Documentation/DocBook/media/v4l/controls.xml

   1   <section id="control">
   2     <title>User Controls</title>
   3
   4     <para>Devices typically have a number of user-settable controls
   5 such as brightness, saturation and so on, which would be presented to
   6 the user on a graphical user interface. But, different devices
   7 will have different controls available, and furthermore, the range of
   8 possible values, and the default value will vary from device to
   9 device. The control ioctls provide the information and a mechanism to
  10 create a nice user interface for these controls that will work
  11 correctly with any device.</para>
  12
  13     <para>All controls are accessed using an ID value. V4L2 defines
  14 several IDs for specific purposes. Drivers can also implement their
  15 own custom controls using <constant>V4L2_CID_PRIVATE_BASE</constant>
  16 and higher values. The pre-defined control IDs have the prefix
  17 <constant>V4L2_CID_</constant>, and are listed in <xref
  18 linkend="control-id" />. The ID is used when querying the attributes of
  19 a control, and when getting or setting the current value.</para>
  20
  21     <para>Generally applications should present controls to the user
  22 without assumptions about their purpose. Each control comes with a
  23 name string the user is supposed to understand. When the purpose is
  24 non-intuitive the driver writer should provide a user manual, a user
  25 interface plug-in or a driver specific panel application. Predefined
  26 IDs were introduced to change a few controls programmatically, for
  27 example to mute a device during a channel switch.</para>
  28
  29     <para>Drivers may enumerate different controls after switching
  30 the current video input or output, tuner or modulator, or audio input
  31 or output. Different in the sense of other bounds, another default and
  32 current value, step size or other menu items. A control with a certain
  33 <emphasis>custom</emphasis> ID can also change name and
  34 type.<footnote>
  35         <para>It will be more convenient for applications if drivers
  36 make use of the <constant>V4L2_CTRL_FLAG_DISABLED</constant> flag, but
  37 that was never required.</para>
  38       </footnote> Control values are stored globally, they do not
  39 change when switching except to stay within the reported bounds. They
  40 also do not change &eg; when the device is opened or closed, when the
  41 tuner radio frequency is changed or generally never without
  42 application request. Since V4L2 specifies no event mechanism, panel
  43 applications intended to cooperate with other panel applications (be
  44 they built into a larger application, as a TV viewer) may need to
  45 regularly poll control values to update their user
  46 interface.<footnote>
  47         <para>Applications could call an ioctl to request events.
  48 After another process called &VIDIOC-S-CTRL; or another ioctl changing
  49 shared properties the &func-select; function would indicate
  50 readability until any ioctl (querying the properties) is
  51 called.</para>
  52       </footnote></para>
  53
  54     <para>
  55       All controls use machine endianness.
  56     </para>
  57
  58     <table pgwide="1" frame="none" id="control-id">
  59       <title>Control IDs</title>
  60       <tgroup cols="3">
  61         &cs-def;
  62         <thead>
  63           <row>
  64             <entry>ID</entry>
  65             <entry>Type</entry>
  66             <entry>Description</entry>
  67           </row>
  68         </thead>
  69         <tbody valign="top">
  70           <row>
  71             <entry><constant>V4L2_CID_BASE</constant></entry>
  72             <entry></entry>
  73             <entry>First predefined ID, equal to
  74 <constant>V4L2_CID_BRIGHTNESS</constant>.</entry>
  75           </row>
  76           <row>
  77             <entry><constant>V4L2_CID_USER_BASE</constant></entry>
  78             <entry></entry>
  79             <entry>Synonym of <constant>V4L2_CID_BASE</constant>.</entry>
  80           </row>
  81           <row>
  82             <entry><constant>V4L2_CID_BRIGHTNESS</constant></entry>
  83             <entry>integer</entry>
  84             <entry>Picture brightness, or more precisely, the black
  85 level.</entry>
  86           </row>
  87           <row>
  88             <entry><constant>V4L2_CID_CONTRAST</constant></entry>
  89             <entry>integer</entry>
  90             <entry>Picture contrast or luma gain.</entry>
  91           </row>
  92           <row>
  93             <entry><constant>V4L2_CID_SATURATION</constant></entry>
  94             <entry>integer</entry>
  95             <entry>Picture color saturation or chroma gain.</entry>
  96           </row>
  97           <row>
  98             <entry><constant>V4L2_CID_HUE</constant></entry>
  99             <entry>integer</entry>
 100             <entry>Hue or color balance.</entry>
 101           </row>
 102           <row>
 103             <entry><constant>V4L2_CID_AUDIO_VOLUME</constant></entry>
 104             <entry>integer</entry>
 105             <entry>Overall audio volume. Note some drivers also
 106 provide an OSS or ALSA mixer interface.</entry>
 107           </row>
 108           <row>
 109             <entry><constant>V4L2_CID_AUDIO_BALANCE</constant></entry>
 110             <entry>integer</entry>
 111             <entry>Audio stereo balance. Minimum corresponds to all
 112 the way left, maximum to right.</entry>
 113           </row>
 114           <row>
 115             <entry><constant>V4L2_CID_AUDIO_BASS</constant></entry>
 116             <entry>integer</entry>
 117             <entry>Audio bass adjustment.</entry>
 118           </row>
 119           <row>
 120             <entry><constant>V4L2_CID_AUDIO_TREBLE</constant></entry>
 121             <entry>integer</entry>
 122             <entry>Audio treble adjustment.</entry>
 123           </row>
 124           <row>
 125             <entry><constant>V4L2_CID_AUDIO_MUTE</constant></entry>
 126             <entry>boolean</entry>
 127             <entry>Mute audio, &ie; set the volume to zero, however
 128 without affecting <constant>V4L2_CID_AUDIO_VOLUME</constant>. Like
 129 ALSA drivers, V4L2 drivers must mute at load time to avoid excessive
 130 noise. Actually the entire device should be reset to a low power
 131 consumption state.</entry>
 132           </row>
 133           <row>
 134             <entry><constant>V4L2_CID_AUDIO_LOUDNESS</constant></entry>
 135             <entry>boolean</entry>
 136             <entry>Loudness mode (bass boost).</entry>
 137           </row>
 138           <row>
 139             <entry><constant>V4L2_CID_BLACK_LEVEL</constant></entry>
 140             <entry>integer</entry>
 141             <entry>Another name for brightness (not a synonym of
 142 <constant>V4L2_CID_BRIGHTNESS</constant>). This control is deprecated
 143 and should not be used in new drivers and applications.</entry>
 144           </row>
 145           <row>
 146             <entry><constant>V4L2_CID_AUTO_WHITE_BALANCE</constant></entry>
 147             <entry>boolean</entry>
 148             <entry>Automatic white balance (cameras).</entry>
 149           </row>
 150           <row>
 151             <entry><constant>V4L2_CID_DO_WHITE_BALANCE</constant></entry>
 152             <entry>button</entry>
 153             <entry>This is an action control. When set (the value is
 154 ignored), the device will do a white balance and then hold the current
 155 setting. Contrast this with the boolean
 156 <constant>V4L2_CID_AUTO_WHITE_BALANCE</constant>, which, when
 157 activated, keeps adjusting the white balance.</entry>
 158           </row>
 159           <row>
 160             <entry><constant>V4L2_CID_RED_BALANCE</constant></entry>
 161             <entry>integer</entry>
 162             <entry>Red chroma balance.</entry>
 163           </row>
 164           <row>
 165             <entry><constant>V4L2_CID_BLUE_BALANCE</constant></entry>
 166             <entry>integer</entry>
 167             <entry>Blue chroma balance.</entry>
 168           </row>
 169           <row>
 170             <entry><constant>V4L2_CID_GAMMA</constant></entry>
 171             <entry>integer</entry>
 172             <entry>Gamma adjust.</entry>
 173           </row>
 174           <row>
 175             <entry><constant>V4L2_CID_WHITENESS</constant></entry>
 176             <entry>integer</entry>
 177             <entry>Whiteness for grey-scale devices. This is a synonym
 178 for <constant>V4L2_CID_GAMMA</constant>. This control is deprecated
 179 and should not be used in new drivers and applications.</entry>
 180           </row>
 181           <row>
 182             <entry><constant>V4L2_CID_EXPOSURE</constant></entry>
 183             <entry>integer</entry>
 184             <entry>Exposure (cameras). [Unit?]</entry>
 185           </row>
 186           <row>
 187             <entry><constant>V4L2_CID_AUTOGAIN</constant></entry>
 188             <entry>boolean</entry>
 189             <entry>Automatic gain/exposure control.</entry>
 190           </row>
 191           <row>
 192             <entry><constant>V4L2_CID_GAIN</constant></entry>
 193             <entry>integer</entry>
 194             <entry>Gain control.</entry>
 195           </row>
 196           <row>
 197             <entry><constant>V4L2_CID_HFLIP</constant></entry>
 198             <entry>boolean</entry>
 199             <entry>Mirror the picture horizontally.</entry>
 200           </row>
 201           <row>
 202             <entry><constant>V4L2_CID_VFLIP</constant></entry>
 203             <entry>boolean</entry>
 204             <entry>Mirror the picture vertically.</entry>
 205           </row>
 206           <row id="v4l2-power-line-frequency">
 207             <entry><constant>V4L2_CID_POWER_LINE_FREQUENCY</constant></entry>
 208             <entry>enum</entry>
 209             <entry>Enables a power line frequency filter to avoid
 210 flicker. Possible values for <constant>enum v4l2_power_line_frequency</constant> are:
 211 <constant>V4L2_CID_POWER_LINE_FREQUENCY_DISABLED</constant> (0),
 212 <constant>V4L2_CID_POWER_LINE_FREQUENCY_50HZ</constant> (1),
 213 <constant>V4L2_CID_POWER_LINE_FREQUENCY_60HZ</constant> (2) and
 214 <constant>V4L2_CID_POWER_LINE_FREQUENCY_AUTO</constant> (3).</entry>
 215           </row>
 216           <row>
 217             <entry><constant>V4L2_CID_HUE_AUTO</constant></entry>
 218             <entry>boolean</entry>
 219             <entry>Enables automatic hue control by the device. The
 220 effect of setting <constant>V4L2_CID_HUE</constant> while automatic
 221 hue control is enabled is undefined, drivers should ignore such
 222 request.</entry>
 223           </row>
 224           <row>
 225             <entry><constant>V4L2_CID_WHITE_BALANCE_TEMPERATURE</constant></entry>
 226             <entry>integer</entry>
 227             <entry>This control specifies the white balance settings
 228 as a color temperature in Kelvin. A driver should have a minimum of
 229 2800 (incandescent) to 6500 (daylight). For more information about
 230 color temperature see <ulink
 231 url="http://en.wikipedia.org/wiki/Color_temperature">Wikipedia</ulink>.</entry>
 232           </row>
 233           <row>
 234             <entry><constant>V4L2_CID_SHARPNESS</constant></entry>
 235             <entry>integer</entry>
 236             <entry>Adjusts the sharpness filters in a camera. The
 237 minimum value disables the filters, higher values give a sharper
 238 picture.</entry>
 239           </row>
 240           <row>
 241             <entry><constant>V4L2_CID_BACKLIGHT_COMPENSATION</constant></entry>
 242             <entry>integer</entry>
 243             <entry>Adjusts the backlight compensation in a camera. The
 244 minimum value disables backlight compensation.</entry>
 245           </row>
 246           <row>
 247             <entry><constant>V4L2_CID_CHROMA_AGC</constant></entry>
 248             <entry>boolean</entry>
 249             <entry>Chroma automatic gain control.</entry>
 250           </row>
 251           <row>
 252             <entry><constant>V4L2_CID_CHROMA_GAIN</constant></entry>
 253             <entry>integer</entry>
 254             <entry>Adjusts the Chroma gain control (for use when chroma AGC
 255             is disabled).</entry>
 256           </row>
 257           <row>
 258             <entry><constant>V4L2_CID_COLOR_KILLER</constant></entry>
 259             <entry>boolean</entry>
 260             <entry>Enable the color killer (&ie; force a black &amp; white image in case of a weak video signal).</entry>
 261           </row>
 262           <row id="v4l2-colorfx">
 263             <entry><constant>V4L2_CID_COLORFX</constant></entry>
 264             <entry>enum</entry>
 265             <entry>Selects a color effect. The following values are defined:
 266             </entry>
 267           </row><row>
 268           <entry></entry>
 269           <entry></entry>
 270             <entrytbl spanname="descr" cols="2">
 271               <tbody valign="top">
 272                 <row>
 273                   <entry><constant>V4L2_COLORFX_NONE</constant>&nbsp;</entry>
 274                   <entry>Color effect is disabled.</entry>
 275                 </row>
 276                 <row>
 277                   <entry><constant>V4L2_COLORFX_ANTIQUE</constant>&nbsp;</entry>
 278                   <entry>An aging (old photo) effect.</entry>
 279                 </row>
 280                 <row>
 281                   <entry><constant>V4L2_COLORFX_ART_FREEZE</constant>&nbsp;</entry>
 282                   <entry>Frost color effect.</entry>
 283                 </row>
 284                 <row>
 285                   <entry><constant>V4L2_COLORFX_AQUA</constant>&nbsp;</entry>
 286                   <entry>Water color, cool tone.</entry>
 287                 </row>
 288                 <row>
 289                   <entry><constant>V4L2_COLORFX_BW</constant>&nbsp;</entry>
 290                   <entry>Black and white.</entry>
 291                 </row>
 292                 <row>
 293                   <entry><constant>V4L2_COLORFX_EMBOSS</constant>&nbsp;</entry>
 294                   <entry>Emboss, the highlights and shadows replace light/dark boundaries
 295                   and low contrast areas are set to a gray background.</entry>
 296                 </row>
 297                 <row>
 298                   <entry><constant>V4L2_COLORFX_GRASS_GREEN</constant>&nbsp;</entry>
 299                   <entry>Grass green.</entry>
 300                 </row>
 301                 <row>
 302                   <entry><constant>V4L2_COLORFX_NEGATIVE</constant>&nbsp;</entry>
 303                   <entry>Negative.</entry>
 304                 </row>
 305                 <row>
 306                   <entry><constant>V4L2_COLORFX_SEPIA</constant>&nbsp;</entry>
 307                   <entry>Sepia tone.</entry>
 308                 </row>
 309                 <row>
 310                   <entry><constant>V4L2_COLORFX_SKETCH</constant>&nbsp;</entry>
 311                   <entry>Sketch.</entry>
 312                 </row>
 313                 <row>
 314                   <entry><constant>V4L2_COLORFX_SKIN_WHITEN</constant>&nbsp;</entry>
 315                   <entry>Skin whiten.</entry>
 316                 </row>
 317                 <row>
 318                   <entry><constant>V4L2_COLORFX_SKY_BLUE</constant>&nbsp;</entry>
 319                   <entry>Sky blue.</entry>
 320                 </row>
 321                 <row>
 322                   <entry><constant>V4L2_COLORFX_SOLARIZATION</constant>&nbsp;</entry>
 323                   <entry>Solarization, the image is partially reversed in tone,
 324                   only color values above or below a certain threshold are inverted.
 325                   </entry>
 326                 </row>
 327                 <row>
 328                   <entry><constant>V4L2_COLORFX_SILHOUETTE</constant>&nbsp;</entry>
 329                   <entry>Silhouette (outline).</entry>
 330                 </row>
 331                 <row>
 332                   <entry><constant>V4L2_COLORFX_VIVID</constant>&nbsp;</entry>
 333                   <entry>Vivid colors.</entry>
 334                 </row>
 335                 <row>
 336                   <entry><constant>V4L2_COLORFX_SET_CBCR</constant>&nbsp;</entry>
 337                   <entry>The Cb and Cr chroma components are replaced by fixed
 338                   coefficients determined by <constant>V4L2_CID_COLORFX_CBCR</constant>
 339                   control.</entry>
 340                 </row>
 341               </tbody>
 342             </entrytbl>
 343           </row>
 344           <row>
 345             <entry><constant>V4L2_CID_COLORFX_CBCR</constant></entry>
 346             <entry>integer</entry>
 347             <entry>Determines the Cb and Cr coefficients for <constant>V4L2_COLORFX_SET_CBCR</constant>
 348             color effect. Bits [7:0] of the supplied 32 bit value are interpreted as
 349             Cr component, bits [15:8] as Cb component and bits [31:16] must be zero.
 350           </entry>
 351           </row>
 352           <row>
 353             <entry><constant>V4L2_CID_AUTOBRIGHTNESS</constant></entry>
 354             <entry>boolean</entry>
 355             <entry>Enable Automatic Brightness.</entry>
 356           </row>
 357           <row>
 358             <entry><constant>V4L2_CID_ROTATE</constant></entry>
 359             <entry>integer</entry>
 360             <entry>Rotates the image by specified angle. Common angles are 90,
 361             270 and 180. Rotating the image to 90 and 270 will reverse the height
 362             and width of the display window. It is necessary to set the new height and
 363             width of the picture using the &VIDIOC-S-FMT; ioctl according to
 364             the rotation angle selected.</entry>
 365           </row>
 366           <row>
 367             <entry><constant>V4L2_CID_BG_COLOR</constant></entry>
 368             <entry>integer</entry>
 369             <entry>Sets the background color on the current output device.
 370             Background color needs to be specified in the RGB24 format. The
 371             supplied 32 bit value is interpreted as bits 0-7 Red color information,
 372             bits 8-15 Green color information, bits 16-23 Blue color
 373             information and bits 24-31 must be zero.</entry>
 374           </row>
 375           <row>
 376             <entry><constant>V4L2_CID_ILLUMINATORS_1</constant>
 377                 <constant>V4L2_CID_ILLUMINATORS_2</constant></entry>
 378             <entry>boolean</entry>
 379             <entry>Switch on or off the illuminator 1 or 2 of the device
 380                 (usually a microscope).</entry>
 381           </row>
 382           <row>
 383             <entry><constant>V4L2_CID_MIN_BUFFERS_FOR_CAPTURE</constant></entry>
 384             <entry>integer</entry>
 385             <entry>This is a read-only control that can be read by the application
 386 and used as a hint to determine the number of CAPTURE buffers to pass to REQBUFS.
 387 The value is the minimum number of CAPTURE buffers that is necessary for hardware
 388 to work.</entry>
 389           </row>
 390           <row>
 391             <entry><constant>V4L2_CID_MIN_BUFFERS_FOR_OUTPUT</constant></entry>
 392             <entry>integer</entry>
 393             <entry>This is a read-only control that can be read by the application
 394 and used as a hint to determine the number of OUTPUT buffers to pass to REQBUFS.
 395 The value is the minimum number of OUTPUT buffers that is necessary for hardware
 396 to work.</entry>
 397           </row>
 398           <row id="v4l2-alpha-component">
 399             <entry><constant>V4L2_CID_ALPHA_COMPONENT</constant></entry>
 400             <entry>integer</entry>
 401             <entry> Sets the alpha color component on the capture device or on
 402             the capture buffer queue of a mem-to-mem device. When a mem-to-mem
 403             device produces frame format that includes an alpha component
 404             (e.g. <link linkend="rgb-formats">packed RGB image formats</link>)
 405             and the alpha value is not defined by the mem-to-mem input data
 406             this control lets you select the alpha component value of all
 407             pixels. It is applicable to any pixel format that contains an alpha
 408             component.
 409             </entry>
 410           </row>
 411           <row>
 412             <entry><constant>V4L2_CID_LASTP1</constant></entry>
 413             <entry></entry>
 414             <entry>End of the predefined control IDs (currently
 415               <constant>V4L2_CID_ALPHA_COMPONENT</constant> + 1).</entry>
 416           </row>
 417           <row>
 418             <entry><constant>V4L2_CID_PRIVATE_BASE</constant></entry>
 419             <entry></entry>
 420             <entry>ID of the first custom (driver specific) control.
 421 Applications depending on particular custom controls should check the
 422 driver name and version, see <xref linkend="querycap" />.</entry>
 423           </row>
 424         </tbody>
 425       </tgroup>
 426     </table>
 427
 428     <para>Applications can enumerate the available controls with the
 429 &VIDIOC-QUERYCTRL; and &VIDIOC-QUERYMENU; ioctls, get and set a
 430 control value with the &VIDIOC-G-CTRL; and &VIDIOC-S-CTRL; ioctls.
 431 Drivers must implement <constant>VIDIOC_QUERYCTRL</constant>,
 432 <constant>VIDIOC_G_CTRL</constant> and
 433 <constant>VIDIOC_S_CTRL</constant> when the device has one or more
 434 controls, <constant>VIDIOC_QUERYMENU</constant> when it has one or
 435 more menu type controls.</para>
 436
 437     <example>
 438       <title>Enumerating all controls</title>
 439
 440       <programlisting>
 441 &v4l2-queryctrl; queryctrl;
 442 &v4l2-querymenu; querymenu;
 443
 444 static void
 445 enumerate_menu (void)
 446 {
 447         printf ("  Menu items:\n");
 448
 449         memset (&amp;querymenu, 0, sizeof (querymenu));
 450         querymenu.id = queryctrl.id;
 451
 452         for (querymenu.index = queryctrl.minimum;
 453              querymenu.index &lt;= queryctrl.maximum;
 454               querymenu.index++) {
 455                 if (0 == ioctl (fd, &VIDIOC-QUERYMENU;, &amp;querymenu)) {
 456                         printf ("  %s\n", querymenu.name);
 457                 }
 458         }
 459 }
 460
 461 memset (&amp;queryctrl, 0, sizeof (queryctrl));
 462
 463 for (queryctrl.id = V4L2_CID_BASE;
 464      queryctrl.id &lt; V4L2_CID_LASTP1;
 465      queryctrl.id++) {
 466         if (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &amp;queryctrl)) {
 467                 if (queryctrl.flags &amp; V4L2_CTRL_FLAG_DISABLED)
 468                         continue;
 469
 470                 printf ("Control %s\n", queryctrl.name);
 471
 472                 if (queryctrl.type == V4L2_CTRL_TYPE_MENU)
 473                         enumerate_menu ();
 474         } else {
 475                 if (errno == EINVAL)
 476                         continue;
 477
 478                 perror ("VIDIOC_QUERYCTRL");
 479                 exit (EXIT_FAILURE);
 480         }
 481 }
 482
 483 for (queryctrl.id = V4L2_CID_PRIVATE_BASE;;
 484      queryctrl.id++) {
 485         if (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &amp;queryctrl)) {
 486                 if (queryctrl.flags &amp; V4L2_CTRL_FLAG_DISABLED)
 487                         continue;
 488
 489                 printf ("Control %s\n", queryctrl.name);
 490
 491                 if (queryctrl.type == V4L2_CTRL_TYPE_MENU)
 492                         enumerate_menu ();
 493         } else {
 494                 if (errno == EINVAL)
 495                         break;
 496
 497                 perror ("VIDIOC_QUERYCTRL");
 498                 exit (EXIT_FAILURE);
 499         }
 500 }
 501 </programlisting>
 502     </example>
 503
 504     <example>
 505       <title>Changing controls</title>
 506
 507       <programlisting>
 508 &v4l2-queryctrl; queryctrl;
 509 &v4l2-control; control;
 510
 511 memset (&amp;queryctrl, 0, sizeof (queryctrl));
 512 queryctrl.id = V4L2_CID_BRIGHTNESS;
 513
 514 if (-1 == ioctl (fd, &VIDIOC-QUERYCTRL;, &amp;queryctrl)) {
 515         if (errno != EINVAL) {
 516                 perror ("VIDIOC_QUERYCTRL");
 517                 exit (EXIT_FAILURE);
 518         } else {
 519                 printf ("V4L2_CID_BRIGHTNESS is not supported\n");
 520         }
 521 } else if (queryctrl.flags &amp; V4L2_CTRL_FLAG_DISABLED) {
 522         printf ("V4L2_CID_BRIGHTNESS is not supported\n");
 523 } else {
 524         memset (&amp;control, 0, sizeof (control));
 525         control.id = V4L2_CID_BRIGHTNESS;
 526         control.value = queryctrl.default_value;
 527
 528         if (-1 == ioctl (fd, &VIDIOC-S-CTRL;, &amp;control)) {
 529                 perror ("VIDIOC_S_CTRL");
 530                 exit (EXIT_FAILURE);
 531         }
 532 }
 533
 534 memset (&amp;control, 0, sizeof (control));
 535 control.id = V4L2_CID_CONTRAST;
 536
 537 if (0 == ioctl (fd, &VIDIOC-G-CTRL;, &amp;control)) {
 538         control.value += 1;
 539
 540         /* The driver may clamp the value or return ERANGE, ignored here */
 541
 542         if (-1 == ioctl (fd, &VIDIOC-S-CTRL;, &amp;control)
 543             &amp;&amp; errno != ERANGE) {
 544                 perror ("VIDIOC_S_CTRL");
 545                 exit (EXIT_FAILURE);
 546         }
 547 /* Ignore if V4L2_CID_CONTRAST is unsupported */
 548 } else if (errno != EINVAL) {
 549         perror ("VIDIOC_G_CTRL");
 550         exit (EXIT_FAILURE);
 551 }
 552
 553 control.id = V4L2_CID_AUDIO_MUTE;
 554 control.value = TRUE; /* silence */
 555
 556 /* Errors ignored */
 557 ioctl (fd, VIDIOC_S_CTRL, &amp;control);
 558 </programlisting>
 559     </example>
 560   </section>
 561
 562   <section id="extended-controls">
 563     <title>Extended Controls</title>
 564
 565     <section>
 566       <title>Introduction</title>
 567
 568       <para>The control mechanism as originally designed was meant
 569 to be used for user settings (brightness, saturation, etc). However,
 570 it turned out to be a very useful model for implementing more
 571 complicated driver APIs where each driver implements only a subset of
 572 a larger API.</para>
 573
 574       <para>The MPEG encoding API was the driving force behind
 575 designing and implementing this extended control mechanism: the MPEG
 576 standard is quite large and the currently supported hardware MPEG
 577 encoders each only implement a subset of this standard. Further more,
 578 many parameters relating to how the video is encoded into an MPEG
 579 stream are specific to the MPEG encoding chip since the MPEG standard
 580 only defines the format of the resulting MPEG stream, not how the
 581 video is actually encoded into that format.</para>
 582
 583       <para>Unfortunately, the original control API lacked some
 584 features needed for these new uses and so it was extended into the
 585 (not terribly originally named) extended control API.</para>
 586
 587       <para>Even though the MPEG encoding API was the first effort
 588 to use the Extended Control API, nowadays there are also other classes
 589 of Extended Controls, such as Camera Controls and FM Transmitter Controls.
 590 The Extended Controls API as well as all Extended Controls classes are
 591 described in the following text.</para>
 592     </section>
 593
 594     <section>
 595       <title>The Extended Control API</title>
 596
 597       <para>Three new ioctls are available: &VIDIOC-G-EXT-CTRLS;,
 598 &VIDIOC-S-EXT-CTRLS; and &VIDIOC-TRY-EXT-CTRLS;. These ioctls act on
 599 arrays of controls (as opposed to the &VIDIOC-G-CTRL; and
 600 &VIDIOC-S-CTRL; ioctls that act on a single control). This is needed
 601 since it is often required to atomically change several controls at
 602 once.</para>
 603
 604       <para>Each of the new ioctls expects a pointer to a
 605 &v4l2-ext-controls;. This structure contains a pointer to the control
 606 array, a count of the number of controls in that array and a control
 607 class. Control classes are used to group similar controls into a
 608 single class. For example, control class
 609 <constant>V4L2_CTRL_CLASS_USER</constant> contains all user controls
 610 (&ie; all controls that can also be set using the old
 611 <constant>VIDIOC_S_CTRL</constant> ioctl). Control class
 612 <constant>V4L2_CTRL_CLASS_MPEG</constant> contains all controls
 613 relating to MPEG encoding, etc.</para>
 614
 615       <para>All controls in the control array must belong to the
 616 specified control class. An error is returned if this is not the
 617 case.</para>
 618
 619       <para>It is also possible to use an empty control array (count
 620 == 0) to check whether the specified control class is
 621 supported.</para>
 622
 623       <para>The control array is a &v4l2-ext-control; array. The
 624 <structname>v4l2_ext_control</structname> structure is very similar to
 625 &v4l2-control;, except for the fact that it also allows for 64-bit
 626 values and pointers to be passed.</para>
 627
 628       <para>It is important to realize that due to the flexibility of
 629 controls it is necessary to check whether the control you want to set
 630 actually is supported in the driver and what the valid range of values
 631 is. So use the &VIDIOC-QUERYCTRL; and &VIDIOC-QUERYMENU; ioctls to
 632 check this. Also note that it is possible that some of the menu
 633 indices in a control of type <constant>V4L2_CTRL_TYPE_MENU</constant>
 634 may not be supported (<constant>VIDIOC_QUERYMENU</constant> will
 635 return an error). A good example is the list of supported MPEG audio
 636 bitrates. Some drivers only support one or two bitrates, others
 637 support a wider range.</para>
 638
 639       <para>
 640         All controls use machine endianness.
 641       </para>
 642     </section>
 643
 644     <section>
 645       <title>Enumerating Extended Controls</title>
 646
 647       <para>The recommended way to enumerate over the extended
 648 controls is by using &VIDIOC-QUERYCTRL; in combination with the
 649 <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant> flag:</para>
 650
 651       <informalexample>
 652         <programlisting>
 653 &v4l2-queryctrl; qctrl;
 654
 655 qctrl.id = V4L2_CTRL_FLAG_NEXT_CTRL;
 656 while (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &amp;qctrl)) {
 657         /* ... */
 658         qctrl.id |= V4L2_CTRL_FLAG_NEXT_CTRL;
 659 }
 660 </programlisting>
 661       </informalexample>
 662
 663       <para>The initial control ID is set to 0 ORed with the
 664 <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant> flag. The
 665 <constant>VIDIOC_QUERYCTRL</constant> ioctl will return the first
 666 control with a higher ID than the specified one. When no such controls
 667 are found an error is returned.</para>
 668
 669       <para>If you want to get all controls within a specific control
 670 class, then you can set the initial
 671 <structfield>qctrl.id</structfield> value to the control class and add
 672 an extra check to break out of the loop when a control of another
 673 control class is found:</para>
 674
 675       <informalexample>
 676         <programlisting>
 677 qctrl.id = V4L2_CTRL_CLASS_MPEG | V4L2_CTRL_FLAG_NEXT_CTRL;
 678 while (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &amp;qctrl)) {
 679         if (V4L2_CTRL_ID2CLASS (qctrl.id) != V4L2_CTRL_CLASS_MPEG)
 680                 break;
 681                 /* ... */
 682                 qctrl.id |= V4L2_CTRL_FLAG_NEXT_CTRL;
 683         }
 684 </programlisting>
 685       </informalexample>
 686
 687       <para>The 32-bit <structfield>qctrl.id</structfield> value is
 688 subdivided into three bit ranges: the top 4 bits are reserved for
 689 flags (&eg; <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant>) and are not
 690 actually part of the ID. The remaining 28 bits form the control ID, of
 691 which the most significant 12 bits define the control class and the
 692 least significant 16 bits identify the control within the control
 693 class. It is guaranteed that these last 16 bits are always non-zero
 694 for controls. The range of 0x1000 and up are reserved for
 695 driver-specific controls. The macro
 696 <constant>V4L2_CTRL_ID2CLASS(id)</constant> returns the control class
 697 ID based on a control ID.</para>
 698
 699       <para>If the driver does not support extended controls, then
 700 <constant>VIDIOC_QUERYCTRL</constant> will fail when used in
 701 combination with <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant>. In
 702 that case the old method of enumerating control should be used (see
 703 1.8). But if it is supported, then it is guaranteed to enumerate over
 704 all controls, including driver-private controls.</para>
 705     </section>
 706
 707     <section>
 708       <title>Creating Control Panels</title>
 709
 710       <para>It is possible to create control panels for a graphical
 711 user interface where the user can select the various controls.
 712 Basically you will have to iterate over all controls using the method
 713 described above. Each control class starts with a control of type
 714 <constant>V4L2_CTRL_TYPE_CTRL_CLASS</constant>.
 715 <constant>VIDIOC_QUERYCTRL</constant> will return the name of this
 716 control class which can be used as the title of a tab page within a
 717 control panel.</para>
 718
 719       <para>The flags field of &v4l2-queryctrl; also contains hints on
 720 the behavior of the control. See the &VIDIOC-QUERYCTRL; documentation
 721 for more details.</para>
 722     </section>
 723
 724     <section id="mpeg-controls">
 725       <title>MPEG Control Reference</title>
 726
 727       <para>Below all controls within the MPEG control class are
 728 described. First the generic controls, then controls specific for
 729 certain hardware.</para>
 730
 731       <section>
 732         <title>Generic MPEG Controls</title>
 733
 734         <table pgwide="1" frame="none" id="mpeg-control-id">
 735           <title>MPEG Control IDs</title>
 736           <tgroup cols="4">
 737             <colspec colname="c1" colwidth="1*" />
 738             <colspec colname="c2" colwidth="6*" />
 739             <colspec colname="c3" colwidth="2*" />
 740             <colspec colname="c4" colwidth="6*" />
 741             <spanspec namest="c1" nameend="c2" spanname="id" />
 742             <spanspec namest="c2" nameend="c4" spanname="descr" />
 743             <thead>
 744               <row>
 745                 <entry spanname="id" align="left">ID</entry>
 746                 <entry align="left">Type</entry>
 747               </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
 748               </row>
 749             </thead>
 750             <tbody valign="top">
 751               <row><entry></entry></row>
 752               <row>
 753                 <entry spanname="id"><constant>V4L2_CID_MPEG_CLASS</constant>&nbsp;</entry>
 754                 <entry>class</entry>
 755               </row><row><entry spanname="descr">The MPEG class
 756 descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
 757 description of this control class. This description can be used as the
 758 caption of a Tab page in a GUI, for example.</entry>
 759               </row>
 760               <row><entry></entry></row>
 761               <row id="v4l2-mpeg-stream-type">
 762                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_TYPE</constant>&nbsp;</entry>
 763                 <entry>enum&nbsp;v4l2_mpeg_stream_type</entry>
 764               </row><row><entry spanname="descr">The MPEG-1, -2 or -4
 765 output stream type. One cannot assume anything here. Each hardware
 766 MPEG encoder tends to support different subsets of the available MPEG
 767 stream types. This control is specific to multiplexed MPEG streams.
 768 The currently defined stream types are:</entry>
 769               </row>
 770               <row>
 771                 <entrytbl spanname="descr" cols="2">
 772                   <tbody valign="top">
 773                     <row>
 774                       <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_PS</constant>&nbsp;</entry>
 775                       <entry>MPEG-2 program stream</entry>
 776                     </row>
 777                     <row>
 778                       <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_TS</constant>&nbsp;</entry>
 779                       <entry>MPEG-2 transport stream</entry>
 780                     </row>
 781                     <row>
 782                       <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG1_SS</constant>&nbsp;</entry>
 783                       <entry>MPEG-1 system stream</entry>
 784                     </row>
 785                     <row>
 786                       <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_DVD</constant>&nbsp;</entry>
 787                       <entry>MPEG-2 DVD-compatible stream</entry>
 788                     </row>
 789                     <row>
 790                       <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG1_VCD</constant>&nbsp;</entry>
 791                       <entry>MPEG-1 VCD-compatible stream</entry>
 792                     </row>
 793                     <row>
 794                       <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_SVCD</constant>&nbsp;</entry>
 795                       <entry>MPEG-2 SVCD-compatible stream</entry>
 796                     </row>
 797                   </tbody>
 798                 </entrytbl>
 799               </row>
 800               <row><entry></entry></row>
 801               <row>
 802                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_PMT</constant>&nbsp;</entry>
 803                 <entry>integer</entry>
 804               </row><row><entry spanname="descr">Program Map Table
 805 Packet ID for the MPEG transport stream (default 16)</entry>
 806               </row>
 807               <row><entry></entry></row>
 808               <row>
 809                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_AUDIO</constant>&nbsp;</entry>
 810                 <entry>integer</entry>
 811               </row><row><entry spanname="descr">Audio Packet ID for
 812 the MPEG transport stream (default 256)</entry>
 813               </row>
 814               <row><entry></entry></row>
 815               <row>
 816                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_VIDEO</constant>&nbsp;</entry>
 817                 <entry>integer</entry>
 818               </row><row><entry spanname="descr">Video Packet ID for
 819 the MPEG transport stream (default 260)</entry>
 820               </row>
 821               <row><entry></entry></row>
 822               <row>
 823                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_PCR</constant>&nbsp;</entry>
 824                 <entry>integer</entry>
 825               </row><row><entry spanname="descr">Packet ID for the
 826 MPEG transport stream carrying PCR fields (default 259)</entry>
 827               </row>
 828               <row><entry></entry></row>
 829               <row>
 830                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PES_ID_AUDIO</constant>&nbsp;</entry>
 831                 <entry>integer</entry>
 832               </row><row><entry spanname="descr">Audio ID for MPEG
 833 PES</entry>
 834               </row>
 835               <row><entry></entry></row>
 836               <row>
 837                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PES_ID_VIDEO</constant>&nbsp;</entry>
 838                 <entry>integer</entry>
 839               </row><row><entry spanname="descr">Video ID for MPEG
 840 PES</entry>
 841               </row>
 842               <row><entry></entry></row>
 843               <row id="v4l2-mpeg-stream-vbi-fmt">
 844                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_VBI_FMT</constant>&nbsp;</entry>
 845                 <entry>enum&nbsp;v4l2_mpeg_stream_vbi_fmt</entry>
 846               </row><row><entry spanname="descr">Some cards can embed
 847 VBI data (&eg; Closed Caption, Teletext) into the MPEG stream. This
 848 control selects whether VBI data should be embedded, and if so, what
 849 embedding method should be used. The list of possible VBI formats
 850 depends on the driver. The currently defined VBI format types
 851 are:</entry>
 852               </row>
 853               <row>
 854                 <entrytbl spanname="descr" cols="2">
 855                   <tbody valign="top">
 856                     <row>
 857                       <entry><constant>V4L2_MPEG_STREAM_VBI_FMT_NONE</constant>&nbsp;</entry>
 858                       <entry>No VBI in the MPEG stream</entry>
 859                     </row>
 860                     <row>
 861                       <entry><constant>V4L2_MPEG_STREAM_VBI_FMT_IVTV</constant>&nbsp;</entry>
 862                       <entry>VBI in private packets, IVTV format (documented
 863 in the kernel sources in the file <filename>Documentation/video4linux/cx2341x/README.vbi</filename>)</entry>
 864                     </row>
 865                   </tbody>
 866                 </entrytbl>
 867               </row>
 868               <row><entry></entry></row>
 869               <row id="v4l2-mpeg-audio-sampling-freq">
 870                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_SAMPLING_FREQ</constant>&nbsp;</entry>
 871                 <entry>enum&nbsp;v4l2_mpeg_audio_sampling_freq</entry>
 872               </row><row><entry spanname="descr">MPEG Audio sampling
 873 frequency. Possible values are:</entry>
 874               </row>
 875               <row>
 876                 <entrytbl spanname="descr" cols="2">
 877                   <tbody valign="top">
 878                     <row>
 879                       <entry><constant>V4L2_MPEG_AUDIO_SAMPLING_FREQ_44100</constant>&nbsp;</entry>
 880                       <entry>44.1 kHz</entry>
 881                     </row>
 882                     <row>
 883                       <entry><constant>V4L2_MPEG_AUDIO_SAMPLING_FREQ_48000</constant>&nbsp;</entry>
 884                       <entry>48 kHz</entry>
 885                     </row>
 886                     <row>
 887                       <entry><constant>V4L2_MPEG_AUDIO_SAMPLING_FREQ_32000</constant>&nbsp;</entry>
 888                       <entry>32 kHz</entry>
 889                     </row>
 890                   </tbody>
 891                 </entrytbl>
 892               </row>
 893               <row><entry></entry></row>
 894               <row id="v4l2-mpeg-audio-encoding">
 895                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_ENCODING</constant>&nbsp;</entry>
 896                 <entry>enum&nbsp;v4l2_mpeg_audio_encoding</entry>
 897               </row><row><entry spanname="descr">MPEG Audio encoding.
 898 This control is specific to multiplexed MPEG streams.
 899 Possible values are:</entry>
 900               </row>
 901               <row>
 902                 <entrytbl spanname="descr" cols="2">
 903                   <tbody valign="top">
 904                     <row>
 905                       <entry><constant>V4L2_MPEG_AUDIO_ENCODING_LAYER_1</constant>&nbsp;</entry>
 906                       <entry>MPEG-1/2 Layer I encoding</entry>
 907                     </row>
 908                     <row>
 909                       <entry><constant>V4L2_MPEG_AUDIO_ENCODING_LAYER_2</constant>&nbsp;</entry>
 910                       <entry>MPEG-1/2 Layer II encoding</entry>
 911                     </row>
 912                     <row>
 913                       <entry><constant>V4L2_MPEG_AUDIO_ENCODING_LAYER_3</constant>&nbsp;</entry>
 914                       <entry>MPEG-1/2 Layer III encoding</entry>
 915                     </row>
 916                     <row>
 917                       <entry><constant>V4L2_MPEG_AUDIO_ENCODING_AAC</constant>&nbsp;</entry>
 918                       <entry>MPEG-2/4 AAC (Advanced Audio Coding)</entry>
 919                     </row>
 920                     <row>
 921                       <entry><constant>V4L2_MPEG_AUDIO_ENCODING_AC3</constant>&nbsp;</entry>
 922                       <entry>AC-3 aka ATSC A/52 encoding</entry>
 923                     </row>
 924                   </tbody>
 925                 </entrytbl>
 926               </row>
 927               <row><entry></entry></row>
 928               <row id="v4l2-mpeg-audio-l1-bitrate">
 929                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_L1_BITRATE</constant>&nbsp;</entry>
 930                 <entry>enum&nbsp;v4l2_mpeg_audio_l1_bitrate</entry>
 931               </row><row><entry spanname="descr">MPEG-1/2 Layer I bitrate.
 932 Possible values are:</entry>
 933               </row>
 934               <row>
 935                 <entrytbl spanname="descr" cols="2">
 936                   <tbody valign="top">
 937                     <row>
 938                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_32K</constant>&nbsp;</entry>
 939                       <entry>32 kbit/s</entry></row>
 940                     <row>
 941                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_64K</constant>&nbsp;</entry>
 942                       <entry>64 kbit/s</entry>
 943                     </row>
 944                     <row>
 945                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_96K</constant>&nbsp;</entry>
 946                       <entry>96 kbit/s</entry>
 947                     </row>
 948                     <row>
 949                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_128K</constant>&nbsp;</entry>
 950                       <entry>128 kbit/s</entry>
 951                     </row>
 952                     <row>
 953                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_160K</constant>&nbsp;</entry>
 954                       <entry>160 kbit/s</entry>
 955                     </row>
 956                     <row>
 957                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_192K</constant>&nbsp;</entry>
 958                       <entry>192 kbit/s</entry>
 959                     </row>
 960                     <row>
 961                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_224K</constant>&nbsp;</entry>
 962                       <entry>224 kbit/s</entry>
 963                     </row>
 964                     <row>
 965                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_256K</constant>&nbsp;</entry>
 966                       <entry>256 kbit/s</entry>
 967                     </row>
 968                     <row>
 969                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_288K</constant>&nbsp;</entry>
 970                       <entry>288 kbit/s</entry>
 971                     </row>
 972                     <row>
 973                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_320K</constant>&nbsp;</entry>
 974                       <entry>320 kbit/s</entry>
 975                     </row>
 976                     <row>
 977                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_352K</constant>&nbsp;</entry>
 978                       <entry>352 kbit/s</entry>
 979                     </row>
 980                     <row>
 981                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_384K</constant>&nbsp;</entry>
 982                       <entry>384 kbit/s</entry>
 983                     </row>
 984                     <row>
 985                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_416K</constant>&nbsp;</entry>
 986                       <entry>416 kbit/s</entry>
 987                     </row>
 988                     <row>
 989                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_448K</constant>&nbsp;</entry>
 990                       <entry>448 kbit/s</entry>
 991                     </row>
 992                   </tbody>
 993                 </entrytbl>
 994               </row>
 995               <row><entry></entry></row>
 996               <row id="v4l2-mpeg-audio-l2-bitrate">
 997                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_L2_BITRATE</constant>&nbsp;</entry>
 998                 <entry>enum&nbsp;v4l2_mpeg_audio_l2_bitrate</entry>
 999               </row><row><entry spanname="descr">MPEG-1/2 Layer II bitrate.
1000 Possible values are:</entry>
1001               </row>
1002               <row>
1003                 <entrytbl spanname="descr" cols="2">
1004                   <tbody valign="top">
1005                     <row>
1006                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_32K</constant>&nbsp;</entry>
1007                       <entry>32 kbit/s</entry>
1008                     </row>
1009                     <row>
1010                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_48K</constant>&nbsp;</entry>
1011                       <entry>48 kbit/s</entry>
1012                     </row>
1013                     <row>
1014                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_56K</constant>&nbsp;</entry>
1015                       <entry>56 kbit/s</entry>
1016                     </row>
1017                     <row>
1018                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_64K</constant>&nbsp;</entry>
1019                       <entry>64 kbit/s</entry>
1020                     </row>
1021                     <row>
1022                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_80K</constant>&nbsp;</entry>
1023                       <entry>80 kbit/s</entry>
1024                     </row>
1025                     <row>
1026                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_96K</constant>&nbsp;</entry>
1027                       <entry>96 kbit/s</entry>
1028                     </row>
1029                     <row>
1030                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_112K</constant>&nbsp;</entry>
1031                       <entry>112 kbit/s</entry>
1032                     </row>
1033                     <row>
1034                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_128K</constant>&nbsp;</entry>
1035                       <entry>128 kbit/s</entry>
1036                     </row>
1037                     <row>
1038                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_160K</constant>&nbsp;</entry>
1039                       <entry>160 kbit/s</entry>
1040                     </row>
1041                     <row>
1042                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_192K</constant>&nbsp;</entry>
1043                       <entry>192 kbit/s</entry>
1044                     </row>
1045                     <row>
1046                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_224K</constant>&nbsp;</entry>
1047                       <entry>224 kbit/s</entry>
1048                     </row>
1049                     <row>
1050                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_256K</constant>&nbsp;</entry>
1051                       <entry>256 kbit/s</entry>
1052                     </row>
1053                     <row>
1054                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_320K</constant>&nbsp;</entry>
1055                       <entry>320 kbit/s</entry>
1056                     </row>
1057                     <row>
1058                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_384K</constant>&nbsp;</entry>
1059                       <entry>384 kbit/s</entry>
1060                     </row>
1061                   </tbody>
1062                 </entrytbl>
1063               </row>
1064               <row><entry></entry></row>
1065               <row id="v4l2-mpeg-audio-l3-bitrate">
1066                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_L3_BITRATE</constant>&nbsp;</entry>
1067                 <entry>enum&nbsp;v4l2_mpeg_audio_l3_bitrate</entry>
1068               </row><row><entry spanname="descr">MPEG-1/2 Layer III bitrate.
1069 Possible values are:</entry>
1070               </row>
1071               <row>
1072                 <entrytbl spanname="descr" cols="2">
1073                   <tbody valign="top">
1074                     <row>
1075                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_32K</constant>&nbsp;</entry>
1076                       <entry>32 kbit/s</entry>
1077                     </row>
1078                     <row>
1079                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_40K</constant>&nbsp;</entry>
1080                       <entry>40 kbit/s</entry>
1081                     </row>
1082                     <row>
1083                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_48K</constant>&nbsp;</entry>
1084                       <entry>48 kbit/s</entry>
1085                     </row>
1086                     <row>
1087                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_56K</constant>&nbsp;</entry>
1088                       <entry>56 kbit/s</entry>
1089                     </row>
1090                     <row>
1091                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_64K</constant>&nbsp;</entry>
1092                       <entry>64 kbit/s</entry>
1093                     </row>
1094                     <row>
1095                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_80K</constant>&nbsp;</entry>
1096                       <entry>80 kbit/s</entry>
1097                     </row>
1098                     <row>
1099                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_96K</constant>&nbsp;</entry>
1100                       <entry>96 kbit/s</entry>
1101                     </row>
1102                     <row>
1103                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_112K</constant>&nbsp;</entry>
1104                       <entry>112 kbit/s</entry>
1105                     </row>
1106                     <row>
1107                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_128K</constant>&nbsp;</entry>
1108                       <entry>128 kbit/s</entry>
1109                     </row>
1110                     <row>
1111                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_160K</constant>&nbsp;</entry>
1112                       <entry>160 kbit/s</entry>
1113                     </row>
1114                     <row>
1115                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_192K</constant>&nbsp;</entry>
1116                       <entry>192 kbit/s</entry>
1117                     </row>
1118                     <row>
1119                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_224K</constant>&nbsp;</entry>
1120                       <entry>224 kbit/s</entry>
1121                     </row>
1122                     <row>
1123                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_256K</constant>&nbsp;</entry>
1124                       <entry>256 kbit/s</entry>
1125                     </row>
1126                     <row>
1127                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_320K</constant>&nbsp;</entry>
1128                       <entry>320 kbit/s</entry>
1129                     </row>
1130                   </tbody>
1131                 </entrytbl>
1132               </row>
1133               <row><entry></entry></row>
1134               <row>
1135                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_AAC_BITRATE</constant>&nbsp;</entry>
1136                 <entry>integer</entry>
1137               </row><row><entry spanname="descr">AAC bitrate in bits per second.</entry>
1138               </row>
1139               <row><entry></entry></row>
1140               <row id="v4l2-mpeg-audio-ac3-bitrate">
1141                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_AC3_BITRATE</constant>&nbsp;</entry>
1142                 <entry>enum&nbsp;v4l2_mpeg_audio_ac3_bitrate</entry>
1143               </row><row><entry spanname="descr">AC-3 bitrate.
1144 Possible values are:</entry>
1145               </row>
1146               <row>
1147                 <entrytbl spanname="descr" cols="2">
1148                   <tbody valign="top">
1149                     <row>
1150                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_32K</constant>&nbsp;</entry>
1151                       <entry>32 kbit/s</entry>
1152                     </row>
1153                     <row>
1154                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_40K</constant>&nbsp;</entry>
1155                       <entry>40 kbit/s</entry>
1156                     </row>
1157                     <row>
1158                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_48K</constant>&nbsp;</entry>
1159                       <entry>48 kbit/s</entry>
1160                     </row>
1161                     <row>
1162                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_56K</constant>&nbsp;</entry>
1163                       <entry>56 kbit/s</entry>
1164                     </row>
1165                     <row>
1166                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_64K</constant>&nbsp;</entry>
1167                       <entry>64 kbit/s</entry>
1168                     </row>
1169                     <row>
1170                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_80K</constant>&nbsp;</entry>
1171                       <entry>80 kbit/s</entry>
1172                     </row>
1173                     <row>
1174                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_96K</constant>&nbsp;</entry>
1175                       <entry>96 kbit/s</entry>
1176                     </row>
1177                     <row>
1178                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_112K</constant>&nbsp;</entry>
1179                       <entry>112 kbit/s</entry>
1180                     </row>
1181                     <row>
1182                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_128K</constant>&nbsp;</entry>
1183                       <entry>128 kbit/s</entry>
1184                     </row>
1185                     <row>
1186                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_160K</constant>&nbsp;</entry>
1187                       <entry>160 kbit/s</entry>
1188                     </row>
1189                     <row>
1190                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_192K</constant>&nbsp;</entry>
1191                       <entry>192 kbit/s</entry>
1192                     </row>
1193                     <row>
1194                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_224K</constant>&nbsp;</entry>
1195                       <entry>224 kbit/s</entry>
1196                     </row>
1197                     <row>
1198                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_256K</constant>&nbsp;</entry>
1199                       <entry>256 kbit/s</entry>
1200                     </row>
1201                     <row>
1202                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_320K</constant>&nbsp;</entry>
1203                       <entry>320 kbit/s</entry>
1204                     </row>
1205                     <row>
1206                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_384K</constant>&nbsp;</entry>
1207                       <entry>384 kbit/s</entry>
1208                     </row>
1209                     <row>
1210                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_448K</constant>&nbsp;</entry>
1211                       <entry>448 kbit/s</entry>
1212                     </row>
1213                     <row>
1214                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_512K</constant>&nbsp;</entry>
1215                       <entry>512 kbit/s</entry>
1216                     </row>
1217                     <row>
1218                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_576K</constant>&nbsp;</entry>
1219                       <entry>576 kbit/s</entry>
1220                     </row>
1221                     <row>
1222                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_640K</constant>&nbsp;</entry>
1223                       <entry>640 kbit/s</entry>
1224                     </row>
1225                   </tbody>
1226                 </entrytbl>
1227               </row>
1228               <row><entry></entry></row>
1229               <row id="v4l2-mpeg-audio-mode">
1230                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_MODE</constant>&nbsp;</entry>
1231                 <entry>enum&nbsp;v4l2_mpeg_audio_mode</entry>
1232               </row><row><entry spanname="descr">MPEG Audio mode.
1233 Possible values are:</entry>
1234               </row>
1235               <row>
1236                 <entrytbl spanname="descr" cols="2">
1237                   <tbody valign="top">
1238                     <row>
1239                       <entry><constant>V4L2_MPEG_AUDIO_MODE_STEREO</constant>&nbsp;</entry>
1240                       <entry>Stereo</entry>
1241                     </row>
1242                     <row>
1243                       <entry><constant>V4L2_MPEG_AUDIO_MODE_JOINT_STEREO</constant>&nbsp;</entry>
1244                       <entry>Joint Stereo</entry>
1245                     </row>
1246                     <row>
1247                       <entry><constant>V4L2_MPEG_AUDIO_MODE_DUAL</constant>&nbsp;</entry>
1248                       <entry>Bilingual</entry>
1249                     </row>
1250                     <row>
1251                       <entry><constant>V4L2_MPEG_AUDIO_MODE_MONO</constant>&nbsp;</entry>
1252                       <entry>Mono</entry>
1253                     </row>
1254                   </tbody>
1255                 </entrytbl>
1256               </row>
1257               <row><entry></entry></row>
1258               <row id="v4l2-mpeg-audio-mode-extension">
1259                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_MODE_EXTENSION</constant>&nbsp;</entry>
1260                 <entry>enum&nbsp;v4l2_mpeg_audio_mode_extension</entry>
1261               </row><row><entry spanname="descr">Joint Stereo
1262 audio mode extension. In Layer I and II they indicate which subbands
1263 are in intensity stereo. All other subbands are coded in stereo. Layer
1264 III is not (yet) supported. Possible values
1265 are:</entry>
1266               </row>
1267               <row>
1268                 <entrytbl spanname="descr" cols="2">
1269                   <tbody valign="top">
1270                     <row>
1271                       <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_4</constant>&nbsp;</entry>
1272                       <entry>Subbands 4-31 in intensity stereo</entry>
1273                     </row>
1274                     <row>
1275                       <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_8</constant>&nbsp;</entry>
1276                       <entry>Subbands 8-31 in intensity stereo</entry>
1277                     </row>
1278                     <row>
1279                       <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_12</constant>&nbsp;</entry>
1280                       <entry>Subbands 12-31 in intensity stereo</entry>
1281                     </row>
1282                     <row>
1283                       <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_16</constant>&nbsp;</entry>
1284                       <entry>Subbands 16-31 in intensity stereo</entry>
1285                     </row>
1286                   </tbody>
1287                 </entrytbl>
1288               </row>
1289               <row><entry></entry></row>
1290               <row id="v4l2-mpeg-audio-emphasis">
1291                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_EMPHASIS</constant>&nbsp;</entry>
1292                 <entry>enum&nbsp;v4l2_mpeg_audio_emphasis</entry>
1293               </row><row><entry spanname="descr">Audio Emphasis.
1294 Possible values are:</entry>
1295               </row>
1296               <row>
1297                 <entrytbl spanname="descr" cols="2">
1298                   <tbody valign="top">
1299                     <row>
1300                       <entry><constant>V4L2_MPEG_AUDIO_EMPHASIS_NONE</constant>&nbsp;</entry>
1301                       <entry>None</entry>
1302                     </row>
1303                     <row>
1304                       <entry><constant>V4L2_MPEG_AUDIO_EMPHASIS_50_DIV_15_uS</constant>&nbsp;</entry>
1305                       <entry>50/15 microsecond emphasis</entry>
1306                     </row>
1307                     <row>
1308                       <entry><constant>V4L2_MPEG_AUDIO_EMPHASIS_CCITT_J17</constant>&nbsp;</entry>
1309                       <entry>CCITT J.17</entry>
1310                     </row>
1311                   </tbody>
1312                 </entrytbl>
1313               </row>
1314               <row><entry></entry></row>
1315               <row id="v4l2-mpeg-audio-crc">
1316                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_CRC</constant>&nbsp;</entry>
1317                 <entry>enum&nbsp;v4l2_mpeg_audio_crc</entry>
1318               </row><row><entry spanname="descr">CRC method. Possible
1319 values are:</entry>
1320               </row>
1321               <row>
1322                 <entrytbl spanname="descr" cols="2">
1323                   <tbody valign="top">
1324                     <row>
1325                       <entry><constant>V4L2_MPEG_AUDIO_CRC_NONE</constant>&nbsp;</entry>
1326                       <entry>None</entry>
1327                     </row>
1328                     <row>
1329                       <entry><constant>V4L2_MPEG_AUDIO_CRC_CRC16</constant>&nbsp;</entry>
1330                       <entry>16 bit parity check</entry>
1331                     </row>
1332                   </tbody>
1333                 </entrytbl>
1334               </row>
1335               <row><entry></entry></row>
1336               <row>
1337                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_MUTE</constant>&nbsp;</entry>
1338                 <entry>boolean</entry>
1339               </row><row><entry spanname="descr">Mutes the audio when
1340 capturing. This is not done by muting audio hardware, which can still
1341 produce a slight hiss, but in the encoder itself, guaranteeing a fixed
1342 and reproducible audio bitstream. 0 = unmuted, 1 = muted.</entry>
1343               </row>
1344               <row><entry></entry></row>
1345               <row id="v4l2-mpeg-audio-dec-playback">
1346                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_DEC_PLAYBACK</constant>&nbsp;</entry>
1347                 <entry>enum&nbsp;v4l2_mpeg_audio_dec_playback</entry>
1348               </row><row><entry spanname="descr">Determines how monolingual audio should be played back.
1349 Possible values are:</entry>
1350               </row>
1351               <row>
1352                 <entrytbl spanname="descr" cols="2">
1353                   <tbody valign="top">
1354                     <row>
1355                       <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_AUTO</constant>&nbsp;</entry>
1356                       <entry>Automatically determines the best playback mode.</entry>
1357                     </row>
1358                     <row>
1359                       <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_STEREO</constant>&nbsp;</entry>
1360                       <entry>Stereo playback.</entry>
1361                     </row>
1362                     <row>
1363                       <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_LEFT</constant>&nbsp;</entry>
1364                       <entry>Left channel playback.</entry>
1365                     </row>
1366                     <row>
1367                       <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_RIGHT</constant>&nbsp;</entry>
1368                       <entry>Right channel playback.</entry>
1369                     </row>
1370                     <row>
1371                       <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_MONO</constant>&nbsp;</entry>
1372                       <entry>Mono playback.</entry>
1373                     </row>
1374                     <row>
1375                       <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_SWAPPED_STEREO</constant>&nbsp;</entry>
1376                       <entry>Stereo playback with swapped left and right channels.</entry>
1377                     </row>
1378                   </tbody>
1379                 </entrytbl>
1380               </row>
1381               <row><entry></entry></row>
1382               <row id="v4l2-mpeg-audio-dec-multilingual-playback">
1383                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_DEC_MULTILINGUAL_PLAYBACK</constant>&nbsp;</entry>
1384                 <entry>enum&nbsp;v4l2_mpeg_audio_dec_playback</entry>
1385               </row><row><entry spanname="descr">Determines how multilingual audio should be played back.</entry>
1386               </row>
1387               <row><entry></entry></row>
1388               <row id="v4l2-mpeg-video-encoding">
1389                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_ENCODING</constant>&nbsp;</entry>
1390                 <entry>enum&nbsp;v4l2_mpeg_video_encoding</entry>
1391               </row><row><entry spanname="descr">MPEG Video encoding
1392 method. This control is specific to multiplexed MPEG streams.
1393 Possible values are:</entry>
1394               </row>
1395               <row>
1396                 <entrytbl spanname="descr" cols="2">
1397                   <tbody valign="top">
1398                     <row>
1399                       <entry><constant>V4L2_MPEG_VIDEO_ENCODING_MPEG_1</constant>&nbsp;</entry>
1400                       <entry>MPEG-1 Video encoding</entry>
1401                     </row>
1402                     <row>
1403                       <entry><constant>V4L2_MPEG_VIDEO_ENCODING_MPEG_2</constant>&nbsp;</entry>
1404                       <entry>MPEG-2 Video encoding</entry>
1405                     </row>
1406                     <row>
1407                       <entry><constant>V4L2_MPEG_VIDEO_ENCODING_MPEG_4_AVC</constant>&nbsp;</entry>
1408                       <entry>MPEG-4 AVC (H.264) Video encoding</entry>
1409                     </row>
1410                   </tbody>
1411                 </entrytbl>
1412               </row>
1413               <row><entry></entry></row>
1414               <row id="v4l2-mpeg-video-aspect">
1415                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_ASPECT</constant>&nbsp;</entry>
1416                 <entry>enum&nbsp;v4l2_mpeg_video_aspect</entry>
1417               </row><row><entry spanname="descr">Video aspect.
1418 Possible values are:</entry>
1419               </row>
1420               <row>
1421                 <entrytbl spanname="descr" cols="2">
1422                   <tbody valign="top">
1423                     <row>
1424                       <entry><constant>V4L2_MPEG_VIDEO_ASPECT_1x1</constant>&nbsp;</entry>
1425                     </row>
1426                     <row>
1427                       <entry><constant>V4L2_MPEG_VIDEO_ASPECT_4x3</constant>&nbsp;</entry>
1428                     </row>
1429                     <row>
1430                       <entry><constant>V4L2_MPEG_VIDEO_ASPECT_16x9</constant>&nbsp;</entry>
1431                     </row>
1432                     <row>
1433                       <entry><constant>V4L2_MPEG_VIDEO_ASPECT_221x100</constant>&nbsp;</entry>
1434                     </row>
1435                   </tbody>
1436                 </entrytbl>
1437               </row>
1438               <row><entry></entry></row>
1439               <row>
1440                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_B_FRAMES</constant>&nbsp;</entry>
1441                 <entry>integer</entry>
1442               </row><row><entry spanname="descr">Number of B-Frames
1443 (default 2)</entry>
1444               </row>
1445               <row><entry></entry></row>
1446               <row>
1447                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_GOP_SIZE</constant>&nbsp;</entry>
1448                 <entry>integer</entry>
1449               </row><row><entry spanname="descr">GOP size (default
1450 12)</entry>
1451               </row>
1452               <row><entry></entry></row>
1453               <row>
1454                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_GOP_CLOSURE</constant>&nbsp;</entry>
1455                 <entry>boolean</entry>
1456               </row><row><entry spanname="descr">GOP closure (default
1457 1)</entry>
1458               </row>
1459               <row><entry></entry></row>
1460               <row>
1461                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_PULLDOWN</constant>&nbsp;</entry>
1462                 <entry>boolean</entry>
1463               </row><row><entry spanname="descr">Enable 3:2 pulldown
1464 (default 0)</entry>
1465               </row>
1466               <row><entry></entry></row>
1467               <row id="v4l2-mpeg-video-bitrate-mode">
1468                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_BITRATE_MODE</constant>&nbsp;</entry>
1469                 <entry>enum&nbsp;v4l2_mpeg_video_bitrate_mode</entry>
1470               </row><row><entry spanname="descr">Video bitrate mode.
1471 Possible values are:</entry>
1472               </row>
1473               <row>
1474                 <entrytbl spanname="descr" cols="2">
1475                   <tbody valign="top">
1476                     <row>
1477                       <entry><constant>V4L2_MPEG_VIDEO_BITRATE_MODE_VBR</constant>&nbsp;</entry>
1478                       <entry>Variable bitrate</entry>
1479                     </row>
1480                     <row>
1481                       <entry><constant>V4L2_MPEG_VIDEO_BITRATE_MODE_CBR</constant>&nbsp;</entry>
1482                       <entry>Constant bitrate</entry>
1483                     </row>
1484                   </tbody>
1485                 </entrytbl>
1486               </row>
1487               <row><entry></entry></row>
1488               <row>
1489                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_BITRATE</constant>&nbsp;</entry>
1490                 <entry>integer</entry>
1491               </row><row><entry spanname="descr">Video bitrate in bits
1492 per second.</entry>
1493               </row>
1494               <row><entry></entry></row>
1495               <row>
1496                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_BITRATE_PEAK</constant>&nbsp;</entry>
1497                 <entry>integer</entry>
1498               </row><row><entry spanname="descr">Peak video bitrate in
1499 bits per second. Must be larger or equal to the average video bitrate.
1500 It is ignored if the video bitrate mode is set to constant
1501 bitrate.</entry>
1502               </row>
1503               <row><entry></entry></row>
1504               <row>
1505                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_TEMPORAL_DECIMATION</constant>&nbsp;</entry>
1506                 <entry>integer</entry>
1507               </row><row><entry spanname="descr">For every captured
1508 frame, skip this many subsequent frames (default 0).</entry>
1509               </row>
1510               <row><entry></entry></row>
1511               <row>
1512                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MUTE</constant>&nbsp;</entry>
1513                 <entry>boolean</entry>
1514               </row>
1515               <row><entry spanname="descr">"Mutes" the video to a
1516 fixed color when capturing. This is useful for testing, to produce a
1517 fixed video bitstream. 0 = unmuted, 1 = muted.</entry>
1518               </row>
1519               <row><entry></entry></row>
1520               <row>
1521                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MUTE_YUV</constant>&nbsp;</entry>
1522                 <entry>integer</entry>
1523               </row><row><entry spanname="descr">Sets the "mute" color
1524 of the video. The supplied 32-bit integer is interpreted as follows (bit
1525 0 = least significant bit):</entry>
1526               </row>
1527               <row>
1528                 <entrytbl spanname="descr" cols="2">
1529                   <tbody valign="top">
1530                     <row>
1531                       <entry>Bit 0:7</entry>
1532                       <entry>V chrominance information</entry>
1533                     </row>
1534                     <row>
1535                       <entry>Bit 8:15</entry>
1536                       <entry>U chrominance information</entry>
1537                     </row>
1538                     <row>
1539                       <entry>Bit 16:23</entry>
1540                       <entry>Y luminance information</entry>
1541                     </row>
1542                     <row>
1543                       <entry>Bit 24:31</entry>
1544                       <entry>Must be zero.</entry>
1545                     </row>
1546                   </tbody>
1547                 </entrytbl>
1548               </row>
1549               <row><entry></entry></row>
1550               <row id="v4l2-mpeg-video-dec-pts">
1551                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_DEC_PTS</constant>&nbsp;</entry>
1552                 <entry>integer64</entry>
1553               </row><row><entry spanname="descr">This read-only control returns the
1554 33-bit video Presentation Time Stamp as defined in ITU T-REC-H.222.0 and ISO/IEC 13818-1 of
1555 the currently displayed frame. This is the same PTS as is used in &VIDIOC-DECODER-CMD;.</entry>
1556               </row>
1557               <row><entry></entry></row>
1558               <row id="v4l2-mpeg-video-dec-frame">
1559                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_DEC_FRAME</constant>&nbsp;</entry>
1560                 <entry>integer64</entry>
1561               </row><row><entry spanname="descr">This read-only control returns the
1562 frame counter of the frame that is currently displayed (decoded). This value is reset to 0 whenever
1563 the decoder is started.</entry>
1564               </row>
1565
1566               <row><entry></entry></row>
1567               <row>
1568                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_DECODER_SLICE_INTERFACE</constant>&nbsp;</entry>
1569                 <entry>boolean</entry>
1570               </row>
1571               <row><entry spanname="descr">If enabled the decoder expects to receive a single slice per buffer, otherwise
1572 the decoder expects a single frame in per buffer. Applicable to the decoder, all codecs.
1573 </entry>
1574               </row>
1575
1576               <row><entry></entry></row>
1577               <row>
1578                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_SAR_ENABLE</constant>&nbsp;</entry>
1579                 <entry>boolean</entry>
1580               </row>
1581               <row><entry spanname="descr">Enable writing sample aspect ratio in the Video Usability Information.
1582 Applicable to the H264 encoder.</entry>
1583               </row>
1584
1585               <row><entry></entry></row>
1586               <row id="v4l2-mpeg-video-h264-vui-sar-idc">
1587                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_SAR_IDC</constant>&nbsp;</entry>
1588                 <entry>enum&nbsp;v4l2_mpeg_video_h264_vui_sar_idc</entry>
1589               </row>
1590               <row><entry spanname="descr">VUI sample aspect ratio indicator for H.264 encoding. The value
1591 is defined in the table E-1 in the standard. Applicable to the H264 encoder.</entry>
1592               </row>
1593               <row>
1594                 <entrytbl spanname="descr" cols="2">
1595                   <tbody valign="top">
1596
1597                         <row>
1598                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_UNSPECIFIED</constant>&nbsp;</entry>
1599                           <entry>Unspecified</entry>
1600                         </row>
1601                         <row>
1602                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_1x1</constant>&nbsp;</entry>
1603                           <entry>1x1</entry>
1604                         </row>
1605                         <row>
1606                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_12x11</constant>&nbsp;</entry>
1607                           <entry>12x11</entry>
1608                         </row>
1609                         <row>
1610                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_10x11</constant>&nbsp;</entry>
1611                           <entry>10x11</entry>
1612                         </row>
1613                         <row>
1614                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_16x11</constant>&nbsp;</entry>
1615                           <entry>16x11</entry>
1616                         </row>
1617                         <row>
1618                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_40x33</constant>&nbsp;</entry>
1619                           <entry>40x33</entry>
1620                         </row>
1621                         <row>
1622                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_24x11</constant>&nbsp;</entry>
1623                           <entry>24x11</entry>
1624                         </row>
1625                         <row>
1626                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_20x11</constant>&nbsp;</entry>
1627                           <entry>20x11</entry>
1628                         </row>
1629                         <row>
1630                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_32x11</constant>&nbsp;</entry>
1631                           <entry>32x11</entry>
1632                         </row>
1633                         <row>
1634                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_80x33</constant>&nbsp;</entry>
1635                           <entry>80x33</entry>
1636                         </row>
1637                         <row>
1638                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_18x11</constant>&nbsp;</entry>
1639                           <entry>18x11</entry>
1640                         </row>
1641                         <row>
1642                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_15x11</constant>&nbsp;</entry>
1643                           <entry>15x11</entry>
1644                         </row>
1645                         <row>
1646                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_64x33</constant>&nbsp;</entry>
1647                           <entry>64x33</entry>
1648                         </row>
1649                         <row>
1650                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_160x99</constant>&nbsp;</entry>
1651                           <entry>160x99</entry>
1652                         </row>
1653                         <row>
1654                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_4x3</constant>&nbsp;</entry>
1655                           <entry>4x3</entry>
1656                         </row>
1657                         <row>
1658                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_3x2</constant>&nbsp;</entry>
1659                           <entry>3x2</entry>
1660                         </row>
1661                         <row>
1662                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_2x1</constant>&nbsp;</entry>
1663                           <entry>2x1</entry>
1664                         </row>
1665                         <row>
1666                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_EXTENDED</constant>&nbsp;</entry>
1667                           <entry>Extended SAR</entry>
1668                         </row>
1669                   </tbody>
1670                 </entrytbl>
1671               </row>
1672
1673               <row><entry></entry></row>
1674               <row>
1675                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_EXT_SAR_WIDTH</constant>&nbsp;</entry>
1676                 <entry>integer</entry>
1677               </row>
1678               <row><entry spanname="descr">Extended sample aspect ratio width for H.264 VUI encoding.
1679 Applicable to the H264 encoder.</entry>
1680               </row>
1681
1682               <row><entry></entry></row>
1683               <row>
1684                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_EXT_SAR_HEIGHT</constant>&nbsp;</entry>
1685                 <entry>integer</entry>
1686               </row>
1687               <row><entry spanname="descr">Extended sample aspect ratio height for H.264 VUI encoding.
1688 Applicable to the H264 encoder.</entry>
1689               </row>
1690
1691               <row><entry></entry></row>
1692               <row id="v4l2-mpeg-video-h264-level">
1693                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LEVEL</constant>&nbsp;</entry>
1694                 <entry>enum&nbsp;v4l2_mpeg_video_h264_level</entry>
1695               </row>
1696               <row><entry spanname="descr">The level information for the H264 video elementary stream.
1697 Applicable to the H264 encoder.
1698 Possible values are:</entry>
1699               </row>
1700               <row>
1701                 <entrytbl spanname="descr" cols="2">
1702                   <tbody valign="top">
1703                     <row>
1704                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_0</constant>&nbsp;</entry>
1705                       <entry>Level 1.0</entry>
1706                     </row>
1707                     <row>
1708                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1B</constant>&nbsp;</entry>
1709                       <entry>Level 1B</entry>
1710                     </row>
1711                     <row>
1712                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_1</constant>&nbsp;</entry>
1713                       <entry>Level 1.1</entry>
1714                     </row>
1715                     <row>
1716                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_2</constant>&nbsp;</entry>
1717                       <entry>Level 1.2</entry>
1718                     </row>
1719                     <row>
1720                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_3</constant>&nbsp;</entry>
1721                       <entry>Level 1.3</entry>
1722                     </row>
1723                     <row>
1724                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_2_0</constant>&nbsp;</entry>
1725                       <entry>Level 2.0</entry>
1726                     </row>
1727                     <row>
1728                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_2_1</constant>&nbsp;</entry>
1729                       <entry>Level 2.1</entry>
1730                     </row>
1731                     <row>
1732                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_2_2</constant>&nbsp;</entry>
1733                       <entry>Level 2.2</entry>
1734                     </row>
1735                     <row>
1736                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_3_0</constant>&nbsp;</entry>
1737                       <entry>Level 3.0</entry>
1738                     </row>
1739                     <row>
1740                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_3_1</constant>&nbsp;</entry>
1741                       <entry>Level 3.1</entry>
1742                     </row>
1743                     <row>
1744                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_3_2</constant>&nbsp;</entry>
1745                       <entry>Level 3.2</entry>
1746                     </row>
1747                     <row>
1748                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_4_0</constant>&nbsp;</entry>
1749                       <entry>Level 4.0</entry>
1750                     </row>
1751                     <row>
1752                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_4_1</constant>&nbsp;</entry>
1753                       <entry>Level 4.1</entry>
1754                     </row>
1755                     <row>
1756                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_4_2</constant>&nbsp;</entry>
1757                       <entry>Level 4.2</entry>
1758                     </row>
1759                     <row>
1760                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_5_0</constant>&nbsp;</entry>
1761                       <entry>Level 5.0</entry>
1762                     </row>
1763                     <row>
1764                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_5_1</constant>&nbsp;</entry>
1765                       <entry>Level 5.1</entry>
1766                     </row>
1767                   </tbody>
1768                 </entrytbl>
1769               </row>
1770
1771               <row><entry></entry></row>
1772               <row id="v4l2-mpeg-video-mpeg4-level">
1773                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_LEVEL</constant>&nbsp;</entry>
1774                 <entry>enum&nbsp;v4l2_mpeg_video_mpeg4_level</entry>
1775               </row>
1776               <row><entry spanname="descr">The level information for the MPEG4 elementary stream.
1777 Applicable to the MPEG4 encoder.
1778 Possible values are:</entry>
1779               </row>
1780               <row>
1781                 <entrytbl spanname="descr" cols="2">
1782                   <tbody valign="top">
1783                     <row>
1784                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_0</constant>&nbsp;</entry>
1785                       <entry>Level 0</entry>
1786                     </row>
1787                     <row>
1788                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_0B</constant>&nbsp;</entry>
1789                       <entry>Level 0b</entry>
1790                     </row>
1791                     <row>
1792                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_1</constant>&nbsp;</entry>
1793                       <entry>Level 1</entry>
1794                     </row>
1795                     <row>
1796                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_2</constant>&nbsp;</entry>
1797                       <entry>Level 2</entry>
1798                     </row>
1799                     <row>
1800                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_3</constant>&nbsp;</entry>
1801                       <entry>Level 3</entry>
1802                     </row>
1803                     <row>
1804                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_3B</constant>&nbsp;</entry>
1805                       <entry>Level 3b</entry>
1806                     </row>
1807                     <row>
1808                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_4</constant>&nbsp;</entry>
1809                       <entry>Level 4</entry>
1810                     </row>
1811                     <row>
1812                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_5</constant>&nbsp;</entry>
1813                       <entry>Level 5</entry>
1814                     </row>
1815                   </tbody>
1816                 </entrytbl>
1817               </row>
1818
1819               <row><entry></entry></row>
1820               <row id="v4l2-mpeg-video-h264-profile">
1821                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_PROFILE</constant>&nbsp;</entry>
1822                 <entry>enum&nbsp;v4l2_mpeg_video_h264_profile</entry>
1823               </row>
1824               <row><entry spanname="descr">The profile information for H264.
1825 Applicable to the H264 encoder.
1826 Possible values are:</entry>
1827               </row>
1828               <row>
1829                 <entrytbl spanname="descr" cols="2">
1830                   <tbody valign="top">
1831                     <row>
1832                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_BASELINE</constant>&nbsp;</entry>
1833                       <entry>Baseline profile</entry>
1834                     </row>
1835                     <row>
1836                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_CONSTRAINED_BASELINE</constant>&nbsp;</entry>
1837                       <entry>Constrained Baseline profile</entry>
1838                     </row>
1839                     <row>
1840                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_MAIN</constant>&nbsp;</entry>
1841                       <entry>Main profile</entry>
1842                     </row>
1843                     <row>
1844                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_EXTENDED</constant>&nbsp;</entry>
1845                       <entry>Extended profile</entry>
1846                     </row>
1847                     <row>
1848                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH</constant>&nbsp;</entry>
1849                       <entry>High profile</entry>
1850                     </row>
1851                     <row>
1852                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_10</constant>&nbsp;</entry>
1853                       <entry>High 10 profile</entry>
1854                     </row>
1855                     <row>
1856                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_422</constant>&nbsp;</entry>
1857                       <entry>High 422 profile</entry>
1858                     </row>
1859                     <row>
1860                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_444_PREDICTIVE</constant>&nbsp;</entry>
1861                       <entry>High 444 Predictive profile</entry>
1862                     </row>
1863                     <row>
1864                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_10_INTRA</constant>&nbsp;</entry>
1865                       <entry>High 10 Intra profile</entry>
1866                     </row>
1867                     <row>
1868                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_422_INTRA</constant>&nbsp;</entry>
1869                       <entry>High 422 Intra profile</entry>
1870                     </row>
1871                     <row>
1872                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_444_INTRA</constant>&nbsp;</entry>
1873                       <entry>High 444 Intra profile</entry>
1874                     </row>
1875                     <row>
1876                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_CAVLC_444_INTRA</constant>&nbsp;</entry>
1877                       <entry>CAVLC 444 Intra profile</entry>
1878                     </row>
1879                     <row>
1880                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_BASELINE</constant>&nbsp;</entry>
1881                       <entry>Scalable Baseline profile</entry>
1882                     </row>
1883                     <row>
1884                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_HIGH</constant>&nbsp;</entry>
1885                       <entry>Scalable High profile</entry>
1886                     </row>
1887                     <row>
1888                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_HIGH_INTRA</constant>&nbsp;</entry>
1889                       <entry>Scalable High Intra profile</entry>
1890                     </row>
1891                     <row>
1892                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_STEREO_HIGH</constant>&nbsp;</entry>
1893                       <entry>Stereo High profile</entry>
1894                     </row>
1895                     <row>
1896                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_MULTIVIEW_HIGH</constant>&nbsp;</entry>
1897                       <entry>Multiview High profile</entry>
1898                     </row>
1899
1900                   </tbody>
1901                 </entrytbl>
1902               </row>
1903
1904               <row><entry></entry></row>
1905               <row id="v4l2-mpeg-video-mpeg4-profile">
1906                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_PROFILE</constant>&nbsp;</entry>
1907                 <entry>enum&nbsp;v4l2_mpeg_video_mpeg4_profile</entry>
1908               </row>
1909               <row><entry spanname="descr">The profile information for MPEG4.
1910 Applicable to the MPEG4 encoder.
1911 Possible values are:</entry>
1912               </row>
1913               <row>
1914                 <entrytbl spanname="descr" cols="2">
1915                   <tbody valign="top">
1916                     <row>
1917                       <entry><constant>V4L2_MPEG_VIDEO_PROFILE_SIMPLE</constant>&nbsp;</entry>
1918                       <entry>Simple profile</entry>
1919                     </row>
1920                     <row>
1921                       <entry><constant>V4L2_MPEG_VIDEO_PROFILE_ADVANCED_SIMPLE</constant>&nbsp;</entry>
1922                       <entry>Advanced Simple profile</entry>
1923                     </row>
1924                     <row>
1925                       <entry><constant>V4L2_MPEG_VIDEO_PROFILE_CORE</constant>&nbsp;</entry>
1926                       <entry>Core profile</entry>
1927                     </row>
1928                     <row>
1929                       <entry><constant>V4L2_MPEG_VIDEO_PROFILE_SIMPLE_SCALABLE</constant>&nbsp;</entry>
1930                       <entry>Simple Scalable profile</entry>
1931                     </row>
1932                     <row>
1933                       <entry><constant>V4L2_MPEG_VIDEO_PROFILE_ADVANCED_CODING_EFFICIENCY</constant>&nbsp;</entry>
1934                       <entry></entry>
1935                     </row>
1936                   </tbody>
1937                 </entrytbl>
1938               </row>
1939
1940               <row><entry></entry></row>
1941               <row>
1942                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MAX_REF_PIC</constant>&nbsp;</entry>
1943                 <entry>integer</entry>
1944               </row>
1945               <row><entry spanname="descr">The maximum number of reference pictures used for encoding.
1946 Applicable to the encoder.
1947 </entry>
1948               </row>
1949
1950               <row><entry></entry></row>
1951               <row id="v4l2-mpeg-video-multi-slice-mode">
1952                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MODE</constant>&nbsp;</entry>
1953                 <entry>enum&nbsp;v4l2_mpeg_video_multi_slice_mode</entry>
1954               </row>
1955               <row><entry spanname="descr">Determines how the encoder should handle division of frame into slices.
1956 Applicable to the encoder.
1957 Possible values are:</entry>
1958               </row>
1959               <row>
1960                 <entrytbl spanname="descr" cols="2">
1961                   <tbody valign="top">
1962                     <row>
1963                       <entry><constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_SINGLE</constant>&nbsp;</entry>
1964                       <entry>Single slice per frame.</entry>
1965                     </row>
1966                     <row>
1967                       <entry><constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_MB</constant>&nbsp;</entry>
1968                       <entry>Multiple slices with set maximum number of macroblocks per slice.</entry>
1969                     </row>
1970                     <row>
1971                       <entry><constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_BYTES</constant>&nbsp;</entry>
1972                       <entry>Multiple slice with set maximum size in bytes per slice.</entry>
1973                     </row>
1974                   </tbody>
1975                 </entrytbl>
1976               </row>
1977
1978               <row><entry></entry></row>
1979               <row>
1980                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MAX_MB</constant>&nbsp;</entry>
1981                 <entry>integer</entry>
1982               </row>
1983               <row><entry spanname="descr">The maximum number of macroblocks in a slice. Used when
1984 <constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MODE</constant> is set to <constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_MB</constant>.
1985 Applicable to the encoder.</entry>
1986               </row>
1987
1988               <row><entry></entry></row>
1989               <row>
1990                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MAX_BYTES</constant>&nbsp;</entry>
1991                 <entry>integer</entry>
1992               </row>
1993               <row><entry spanname="descr">The maximum size of a slice in bytes. Used when
1994 <constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MODE</constant> is set to <constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_BYTES</constant>.
1995 Applicable to the encoder.</entry>
1996               </row>
1997
1998               <row><entry></entry></row>
1999               <row id="v4l2-mpeg-video-h264-loop-filter-mode">
2000                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LOOP_FILTER_MODE</constant>&nbsp;</entry>
2001                 <entry>enum&nbsp;v4l2_mpeg_video_h264_loop_filter_mode</entry>
2002               </row>
2003               <row><entry spanname="descr">Loop filter mode for H264 encoder.
2004 Possible values are:</entry>
2005               </row>
2006               <row>
2007                 <entrytbl spanname="descr" cols="2">
2008                   <tbody valign="top">
2009                     <row>
2010                       <entry><constant>V4L2_MPEG_VIDEO_H264_LOOP_FILTER_MODE_ENABLED</constant>&nbsp;</entry>
2011                       <entry>Loop filter is enabled.</entry>
2012                     </row>
2013                     <row>
2014                       <entry><constant>V4L2_MPEG_VIDEO_H264_LOOP_FILTER_MODE_DISABLED</constant>&nbsp;</entry>
2015                       <entry>Loop filter is disabled.</entry>
2016                     </row>
2017                     <row>
2018                       <entry><constant>V4L2_MPEG_VIDEO_H264_LOOP_FILTER_MODE_DISABLED_AT_SLICE_BOUNDARY</constant>&nbsp;</entry>
2019                       <entry>Loop filter is disabled at the slice boundary.</entry>
2020                     </row>
2021                   </tbody>
2022                 </entrytbl>
2023               </row>
2024
2025               <row><entry></entry></row>
2026               <row>
2027                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LOOP_FILTER_ALPHA</constant>&nbsp;</entry>
2028                 <entry>integer</entry>
2029               </row>
2030               <row><entry spanname="descr">Loop filter alpha coefficient, defined in the H264 standard.
2031 Applicable to the H264 encoder.</entry>
2032               </row>
2033
2034               <row><entry></entry></row>
2035               <row>
2036                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LOOP_FILTER_BETA</constant>&nbsp;</entry>
2037                 <entry>integer</entry>
2038               </row>
2039               <row><entry spanname="descr">Loop filter beta coefficient, defined in the H264 standard.
2040 Applicable to the H264 encoder.</entry>
2041               </row>
2042
2043               <row><entry></entry></row>
2044               <row id="v4l2-mpeg-video-h264-entropy-mode">
2045                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_ENTROPY_MODE</constant>&nbsp;</entry>
2046                 <entry>enum&nbsp;v4l2_mpeg_video_h264_entropy_mode</entry>
2047               </row>
2048               <row><entry spanname="descr">Entropy coding mode for H264 - CABAC/CAVALC.
2049 Applicable to the H264 encoder.
2050 Possible values are:</entry>
2051               </row>
2052               <row>
2053                 <entrytbl spanname="descr" cols="2">
2054                   <tbody valign="top">
2055                     <row>
2056                       <entry><constant>V4L2_MPEG_VIDEO_H264_ENTROPY_MODE_CAVLC</constant>&nbsp;</entry>
2057                       <entry>Use CAVLC entropy coding.</entry>
2058                     </row>
2059                     <row>
2060                       <entry><constant>V4L2_MPEG_VIDEO_H264_ENTROPY_MODE_CABAC</constant>&nbsp;</entry>
2061                       <entry>Use CABAC entropy coding.</entry>
2062                     </row>
2063                   </tbody>
2064                 </entrytbl>
2065               </row>
2066
2067               <row><entry></entry></row>
2068               <row>
2069                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_8X8_TRANSFORM</constant>&nbsp;</entry>
2070                 <entry>boolean</entry>
2071               </row>
2072               <row><entry spanname="descr">Enable 8X8 transform for H264. Applicable to the H264 encoder.</entry>
2073               </row>
2074
2075               <row><entry></entry></row>
2076               <row>
2077                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_CYCLIC_INTRA_REFRESH_MB</constant>&nbsp;</entry>
2078                 <entry>integer</entry>
2079               </row>
2080               <row><entry spanname="descr">Cyclic intra macroblock refresh. This is the number of continuous macroblocks
2081 refreshed every frame. Each frame a successive set of macroblocks is refreshed until the cycle completes and starts from the
2082 top of the frame. Applicable to H264, H263 and MPEG4 encoder.</entry>
2083               </row>
2084
2085               <row><entry></entry></row>
2086               <row>
2087                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_FRAME_RC_ENABLE</constant>&nbsp;</entry>
2088                 <entry>boolean</entry>
2089               </row>
2090               <row><entry spanname="descr">Frame level rate control enable.
2091 If this control is disabled then the quantization parameter for each frame type is constant and set with appropriate controls
2092 (e.g. <constant>V4L2_CID_MPEG_VIDEO_H263_I_FRAME_QP</constant>).
2093 If frame rate control is enabled then quantization parameter is adjusted to meet the chosen bitrate. Minimum and maximum value
2094 for the quantization parameter can be set with appropriate controls (e.g. <constant>V4L2_CID_MPEG_VIDEO_H263_MIN_QP</constant>).
2095 Applicable to encoders.</entry>
2096               </row>
2097
2098               <row><entry></entry></row>
2099               <row>
2100                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>&nbsp;</entry>
2101                 <entry>boolean</entry>
2102               </row>
2103               <row><entry spanname="descr">Macroblock level rate control enable.
2104 Applicable to the MPEG4 and H264 encoders.</entry>
2105               </row>
2106
2107               <row><entry></entry></row>
2108               <row>
2109                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_QPEL</constant>&nbsp;</entry>
2110                 <entry>boolean</entry>
2111               </row>
2112               <row><entry spanname="descr">Quarter pixel motion estimation for MPEG4. Applicable to the MPEG4 encoder.</entry>
2113               </row>
2114
2115               <row><entry></entry></row>
2116               <row>
2117                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_I_FRAME_QP</constant>&nbsp;</entry>
2118                 <entry>integer</entry>
2119               </row>
2120               <row><entry spanname="descr">Quantization parameter for an I frame for H263. Valid range: from 1 to 31.</entry>
2121               </row>
2122
2123               <row><entry></entry></row>
2124               <row>
2125                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_MIN_QP</constant>&nbsp;</entry>
2126                 <entry>integer</entry>
2127               </row>
2128               <row><entry spanname="descr">Minimum quantization parameter for H263. Valid range: from 1 to 31.</entry>
2129               </row>
2130
2131               <row><entry></entry></row>
2132               <row>
2133                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_MAX_QP</constant>&nbsp;</entry>
2134                 <entry>integer</entry>
2135               </row>
2136               <row><entry spanname="descr">Maximum quantization parameter for H263. Valid range: from 1 to 31.</entry>
2137               </row>
2138
2139               <row><entry></entry></row>
2140               <row>
2141                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_P_FRAME_QP</constant>&nbsp;</entry>
2142                 <entry>integer</entry>
2143               </row>
2144               <row><entry spanname="descr">Quantization parameter for an P frame for H263. Valid range: from 1 to 31.</entry>
2145               </row>
2146
2147               <row><entry></entry></row>
2148               <row>
2149                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_B_FRAME_QP</constant>&nbsp;</entry>
2150                 <entry>integer</entry>
2151               </row>
2152               <row><entry spanname="descr">Quantization parameter for an B frame for H263. Valid range: from 1 to 31.</entry>
2153               </row>
2154
2155               <row><entry></entry></row>
2156               <row>
2157                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_I_FRAME_QP</constant>&nbsp;</entry>
2158                 <entry>integer</entry>
2159               </row>
2160               <row><entry spanname="descr">Quantization parameter for an I frame for H264. Valid range: from 0 to 51.</entry>
2161               </row>
2162
2163               <row><entry></entry></row>
2164               <row>
2165                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_MIN_QP</constant>&nbsp;</entry>
2166                 <entry>integer</entry>
2167               </row>
2168               <row><entry spanname="descr">Minimum quantization parameter for H264. Valid range: from 0 to 51.</entry>
2169               </row>
2170
2171               <row><entry></entry></row>
2172               <row>
2173                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_MAX_QP</constant>&nbsp;</entry>
2174                 <entry>integer</entry>
2175               </row>
2176               <row><entry spanname="descr">Maximum quantization parameter for H264. Valid range: from 0 to 51.</entry>
2177               </row>
2178
2179               <row><entry></entry></row>
2180               <row>
2181                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_P_FRAME_QP</constant>&nbsp;</entry>
2182                 <entry>integer</entry>
2183               </row>
2184               <row><entry spanname="descr">Quantization parameter for an P frame for H264. Valid range: from 0 to 51.</entry>
2185               </row>
2186
2187               <row><entry></entry></row>
2188               <row>
2189                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_B_FRAME_QP</constant>&nbsp;</entry>
2190                 <entry>integer</entry>
2191               </row>
2192               <row><entry spanname="descr">Quantization parameter for an B frame for H264. Valid range: from 0 to 51.</entry>
2193               </row>
2194
2195               <row><entry></entry></row>
2196               <row>
2197                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_I_FRAME_QP</constant>&nbsp;</entry>
2198                 <entry>integer</entry>
2199               </row>
2200               <row><entry spanname="descr">Quantization parameter for an I frame for MPEG4. Valid range: from 1 to 31.</entry>
2201               </row>
2202
2203               <row><entry></entry></row>
2204               <row>
2205                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_MIN_QP</constant>&nbsp;</entry>
2206                 <entry>integer</entry>
2207               </row>
2208               <row><entry spanname="descr">Minimum quantization parameter for MPEG4. Valid range: from 1 to 31.</entry>
2209               </row>
2210
2211               <row><entry></entry></row>
2212               <row>
2213                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_MAX_QP</constant>&nbsp;</entry>
2214                 <entry>integer</entry>
2215               </row>
2216               <row><entry spanname="descr">Maximum quantization parameter for MPEG4. Valid range: from 1 to 31.</entry>
2217               </row>
2218
2219               <row><entry></entry></row>
2220               <row>
2221                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_P_FRAME_QP</constant>&nbsp;</entry>
2222                 <entry>integer</entry>
2223               </row>
2224               <row><entry spanname="descr">Quantization parameter for an P frame for MPEG4. Valid range: from 1 to 31.</entry>
2225               </row>
2226
2227               <row><entry></entry></row>
2228               <row>
2229                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_B_FRAME_QP</constant>&nbsp;</entry>
2230                 <entry>integer</entry>
2231               </row>
2232               <row><entry spanname="descr">Quantization parameter for an B frame for MPEG4. Valid range: from 1 to 31.</entry>
2233               </row>
2234
2235               <row><entry></entry></row>
2236               <row>
2237                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VBV_SIZE</constant>&nbsp;</entry>
2238                 <entry>integer</entry>
2239               </row>
2240               <row><entry spanname="descr">The Video Buffer Verifier size in kilobytes, it is used as a limitation of frame skip.
2241 The VBV is defined in the standard as a mean to verify that the produced stream will be successfully decoded.
2242 The standard describes it as "Part of a hypothetical decoder that is conceptually connected to the
2243 output of the encoder. Its purpose is to provide a constraint on the variability of the data rate that an
2244 encoder or editing process may produce.".
2245 Applicable to the MPEG1, MPEG2, MPEG4 encoders.</entry>
2246               </row>
2247
2248               <row><entry></entry></row>
2249               <row id="v4l2-mpeg-video-vbv-delay">
2250                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VBV_DELAY</constant>&nbsp;</entry>
2251                 <entry>integer</entry>
2252               </row><row><entry spanname="descr">Sets the initial delay in milliseconds for
2253 VBV buffer control.</entry>
2254               </row>
2255
2256               <row><entry></entry></row>
2257               <row>
2258                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_CPB_SIZE</constant>&nbsp;</entry>
2259                 <entry>integer</entry>
2260               </row>
2261               <row><entry spanname="descr">The Coded Picture Buffer size in kilobytes, it is used as a limitation of frame skip.
2262 The CPB is defined in the H264 standard as a mean to verify that the produced stream will be successfully decoded.
2263 Applicable to the H264 encoder.</entry>
2264               </row>
2265
2266               <row><entry></entry></row>
2267               <row>
2268                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_I_PERIOD</constant>&nbsp;</entry>
2269                 <entry>integer</entry>
2270               </row>
2271               <row><entry spanname="descr">Period between I-frames in the open GOP for H264. In case of an open GOP
2272 this is the period between two I-frames. The period between IDR (Instantaneous Decoding Refresh) frames is taken from the GOP_SIZE control.
2273 An IDR frame, which stands for Instantaneous Decoding Refresh is an I-frame after which no prior frames are
2274 referenced. This means that a stream can be restarted from an IDR frame without the need to store or decode any
2275 previous frames. Applicable to the H264 encoder.</entry>
2276               </row>
2277
2278               <row><entry></entry></row>
2279               <row id="v4l2-mpeg-video-header-mode">
2280                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_HEADER_MODE</constant>&nbsp;</entry>
2281                 <entry>enum&nbsp;v4l2_mpeg_video_header_mode</entry>
2282               </row>
2283               <row><entry spanname="descr">Determines whether the header is returned as the first buffer or is
2284 it returned together with the first frame. Applicable to encoders.
2285 Possible values are:</entry>
2286               </row>
2287               <row>
2288                 <entrytbl spanname="descr" cols="2">
2289                   <tbody valign="top">
2290                     <row>
2291                       <entry><constant>V4L2_MPEG_VIDEO_HEADER_MODE_SEPARATE</constant>&nbsp;</entry>
2292                       <entry>The stream header is returned separately in the first buffer.</entry>
2293                     </row>
2294                     <row>
2295                       <entry><constant>V4L2_MPEG_VIDEO_HEADER_MODE_JOINED_WITH_1ST_FRAME</constant>&nbsp;</entry>
2296                       <entry>The stream header is returned together with the first encoded frame.</entry>
2297                     </row>
2298                   </tbody>
2299                 </entrytbl>
2300               </row>
2301               <row><entry></entry></row>
2302               <row>
2303                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_DECODER_MPEG4_DEBLOCK_FILTER</constant>&nbsp;</entry>
2304                 <entry>boolean</entry>
2305               </row><row><entry spanname="descr">Enabled the deblocking post processing filter for MPEG4 decoder.
2306 Applicable to the MPEG4 decoder.</entry>
2307               </row>
2308               <row><entry></entry></row>
2309               <row>
2310                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_VOP_TIME_RES</constant>&nbsp;</entry>
2311                 <entry>integer</entry>
2312               </row><row><entry spanname="descr">vop_time_increment_resolution value for MPEG4. Applicable to the MPEG4 encoder.</entry>
2313               </row>
2314               <row><entry></entry></row>
2315               <row>
2316                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_VOP_TIME_INC</constant>&nbsp;</entry>
2317                 <entry>integer</entry>
2318               </row><row><entry spanname="descr">vop_time_increment value for MPEG4. Applicable to the MPEG4 encoder.</entry>
2319               </row>
2320
2321               <row><entry></entry></row>
2322               <row>
2323                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_SEI_FRAME_PACKING</constant>&nbsp;</entry>
2324                 <entry>boolean</entry>
2325               </row>
2326               <row><entry spanname="descr">Enable generation of frame packing supplemental enhancement information in the encoded bitstream.
2327 The frame packing SEI message contains the arrangement of L and R planes for 3D viewing. Applicable to the H264 encoder.</entry>
2328               </row>
2329
2330               <row><entry></entry></row>
2331               <row>
2332                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_SEI_FP_CURRENT_FRAME_0</constant>&nbsp;</entry>
2333                 <entry>boolean</entry>
2334               </row>
2335               <row><entry spanname="descr">Sets current frame as frame0 in frame packing SEI.
2336 Applicable to the H264 encoder.</entry>
2337               </row>
2338
2339               <row><entry></entry></row>
2340               <row id="v4l2-mpeg-video-h264-sei-fp-arrangement-type">
2341                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE</constant>&nbsp;</entry>
2342                 <entry>enum&nbsp;v4l2_mpeg_video_h264_sei_fp_arrangement_type</entry>
2343               </row>
2344               <row><entry spanname="descr">Frame packing arrangement type for H264 SEI.
2345 Applicable to the H264 encoder.
2346 Possible values are:</entry>
2347               </row>
2348               <row>
2349                 <entrytbl spanname="descr" cols="2">
2350                   <tbody valign="top">
2351                     <row>
2352                       <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_CHEKERBOARD</constant>&nbsp;</entry>
2353                       <entry>Pixels are alternatively from L and R.</entry>
2354                     </row>
2355                     <row>
2356                       <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_COLUMN</constant>&nbsp;</entry>
2357                       <entry>L and R are interlaced by column.</entry>
2358                     </row>
2359                     <row>
2360                       <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_ROW</constant>&nbsp;</entry>
2361                       <entry>L and R are interlaced by row.</entry>
2362                     </row>
2363                     <row>
2364                       <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_SIDE_BY_SIDE</constant>&nbsp;</entry>
2365                       <entry>L is on the left, R on the right.</entry>
2366                     </row>
2367                     <row>
2368                       <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_TOP_BOTTOM</constant>&nbsp;</entry>
2369                       <entry>L is on top, R on bottom.</entry>
2370                     </row>
2371                     <row>
2372                       <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_TEMPORAL</constant>&nbsp;</entry>
2373                       <entry>One view per frame.</entry>
2374                     </row>
2375                   </tbody>
2376                 </entrytbl>
2377               </row>
2378
2379               <row><entry></entry></row>
2380               <row>
2381                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO</constant>&nbsp;</entry>
2382                 <entry>boolean</entry>
2383               </row>
2384               <row><entry spanname="descr">Enables flexible macroblock ordering in the encoded bitstream. It is a technique
2385 used for restructuring the ordering of macroblocks in pictures. Applicable to the H264 encoder.</entry>
2386               </row>
2387
2388               <row><entry></entry></row>
2389               <row id="v4l2-mpeg-video-h264-fmo-map-type">
2390                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_MAP_TYPE</constant>&nbsp;</entry>
2391                 <entry>enum&nbsp;v4l2_mpeg_video_h264_fmo_map_type</entry>
2392               </row>
2393               <row><entry spanname="descr">When using FMO, the map type divides the image in different scan patterns of macroblocks.
2394 Applicable to the H264 encoder.
2395 Possible values are:</entry>
2396               </row>
2397               <row>
2398                 <entrytbl spanname="descr" cols="2">
2399                   <tbody valign="top">
2400                     <row>
2401                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_INTERLEAVED_SLICES</constant>&nbsp;</entry>
2402                       <entry>Slices are interleaved one after other with macroblocks in run length order.</entry>
2403                     </row>
2404                     <row>
2405                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_SCATTERED_SLICES</constant>&nbsp;</entry>
2406                       <entry>Scatters the macroblocks based on a mathematical function known to both encoder and decoder.</entry>
2407                     </row>
2408                     <row>
2409                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_FOREGROUND_WITH_LEFT_OVER</constant>&nbsp;</entry>
2410                       <entry>Macroblocks arranged in rectangular areas or regions of interest.</entry>
2411                     </row>
2412                     <row>
2413                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_BOX_OUT</constant>&nbsp;</entry>
2414                       <entry>Slice groups grow in a cyclic way from centre to outwards.</entry>
2415                     </row>
2416                     <row>
2417                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_RASTER_SCAN</constant>&nbsp;</entry>
2418                       <entry>Slice groups grow in raster scan pattern from left to right.</entry>
2419                     </row>
2420                     <row>
2421                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_WIPE_SCAN</constant>&nbsp;</entry>
2422                       <entry>Slice groups grow in wipe scan pattern from top to bottom.</entry>
2423                     </row>
2424                     <row>
2425                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_EXPLICIT</constant>&nbsp;</entry>
2426                       <entry>User defined map type.</entry>
2427                     </row>
2428                   </tbody>
2429                 </entrytbl>
2430               </row>
2431
2432               <row><entry></entry></row>
2433               <row>
2434                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_SLICE_GROUP</constant>&nbsp;</entry>
2435                 <entry>integer</entry>
2436               </row>
2437               <row><entry spanname="descr">Number of slice groups in FMO.
2438 Applicable to the H264 encoder.</entry>
2439               </row>
2440
2441               <row><entry></entry></row>
2442               <row id="v4l2-mpeg-video-h264-fmo-change-direction">
2443                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_CHANGE_DIRECTION</constant>&nbsp;</entry>
2444                 <entry>enum&nbsp;v4l2_mpeg_video_h264_fmo_change_dir</entry>
2445               </row>
2446               <row><entry spanname="descr">Specifies a direction of the slice group change for raster and wipe maps.
2447 Applicable to the H264 encoder.
2448 Possible values are:</entry>
2449               </row>
2450               <row>
2451                 <entrytbl spanname="descr" cols="2">
2452                   <tbody valign="top">
2453                     <row>
2454                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_CHANGE_DIR_RIGHT</constant>&nbsp;</entry>
2455                       <entry>Raster scan or wipe right.</entry>
2456                     </row>
2457                     <row>
2458                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_CHANGE_DIR_LEFT</constant>&nbsp;</entry>
2459                       <entry>Reverse raster scan or wipe left.</entry>
2460                     </row>
2461                   </tbody>
2462                 </entrytbl>
2463               </row>
2464
2465               <row><entry></entry></row>
2466               <row>
2467                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_CHANGE_RATE</constant>&nbsp;</entry>
2468                 <entry>integer</entry>
2469               </row>
2470               <row><entry spanname="descr">Specifies the size of the first slice group for raster and wipe map.
2471 Applicable to the H264 encoder.</entry>
2472               </row>
2473
2474               <row><entry></entry></row>
2475               <row>
2476                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_RUN_LENGTH</constant>&nbsp;</entry>
2477                 <entry>integer</entry>
2478               </row>
2479               <row><entry spanname="descr">Specifies the number of consecutive macroblocks for the interleaved map.
2480 Applicable to the H264 encoder.</entry>
2481               </row>
2482
2483               <row><entry></entry></row>
2484               <row>
2485                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_ASO</constant>&nbsp;</entry>
2486                 <entry>boolean</entry>
2487               </row>
2488               <row><entry spanname="descr">Enables arbitrary slice ordering in encoded bitstream.
2489 Applicable to the H264 encoder.</entry>
2490               </row>
2491
2492               <row><entry></entry></row>
2493               <row>
2494                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_ASO_SLICE_ORDER</constant>&nbsp;</entry>
2495                 <entry>integer</entry>
2496               </row><row><entry spanname="descr">Specifies the slice order in ASO. Applicable to the H264 encoder.
2497 The supplied 32-bit integer is interpreted as follows (bit
2498 0 = least significant bit):</entry>
2499               </row>
2500               <row>
2501                 <entrytbl spanname="descr" cols="2">
2502                   <tbody valign="top">
2503                     <row>
2504                       <entry>Bit 0:15</entry>
2505                       <entry>Slice ID</entry>
2506                     </row>
2507                     <row>
2508                       <entry>Bit 16:32</entry>
2509                       <entry>Slice position or order</entry>
2510                     </row>
2511                   </tbody>
2512                 </entrytbl>
2513               </row>
2514
2515               <row><entry></entry></row>
2516               <row>
2517                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING</constant>&nbsp;</entry>
2518                 <entry>boolean</entry>
2519               </row>
2520               <row><entry spanname="descr">Enables H264 hierarchical coding.
2521 Applicable to the H264 encoder.</entry>
2522               </row>
2523
2524               <row><entry></entry></row>
2525               <row id="v4l2-mpeg-video-h264-hierarchical-coding-type">
2526                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING_TYPE</constant>&nbsp;</entry>
2527                 <entry>enum&nbsp;v4l2_mpeg_video_h264_hierarchical_coding_type</entry>
2528               </row>
2529               <row><entry spanname="descr">Specifies the hierarchical coding type.
2530 Applicable to the H264 encoder.
2531 Possible values are:</entry>
2532               </row>
2533               <row>
2534                 <entrytbl spanname="descr" cols="2">
2535                   <tbody valign="top">
2536                     <row>
2537                       <entry><constant>V4L2_MPEG_VIDEO_H264_HIERARCHICAL_CODING_B</constant>&nbsp;</entry>
2538                       <entry>Hierarchical B coding.</entry>
2539                     </row>
2540                     <row>
2541                       <entry><constant>V4L2_MPEG_VIDEO_H264_HIERARCHICAL_CODING_P</constant>&nbsp;</entry>
2542                       <entry>Hierarchical P coding.</entry>
2543                     </row>
2544                   </tbody>
2545                 </entrytbl>
2546               </row>
2547
2548               <row><entry></entry></row>
2549               <row>
2550                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING_LAYER</constant>&nbsp;</entry>
2551                 <entry>integer</entry>
2552               </row>
2553               <row><entry spanname="descr">Specifies the number of hierarchical coding layers.
2554 Applicable to the H264 encoder.</entry>
2555               </row>
2556
2557               <row><entry></entry></row>
2558               <row>
2559                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING_LAYER_QP</constant>&nbsp;</entry>
2560                 <entry>integer</entry>
2561               </row><row><entry spanname="descr">Specifies a user defined QP for each layer. Applicable to the H264 encoder.
2562 The supplied 32-bit integer is interpreted as follows (bit
2563 0 = least significant bit):</entry>
2564               </row>
2565               <row>
2566                 <entrytbl spanname="descr" cols="2">
2567                   <tbody valign="top">
2568                     <row>
2569                       <entry>Bit 0:15</entry>
2570                       <entry>QP value</entry>
2571                     </row>
2572                     <row>
2573                       <entry>Bit 16:32</entry>
2574                       <entry>Layer number</entry>
2575                     </row>
2576                   </tbody>
2577                 </entrytbl>
2578               </row>
2579
2580             </tbody>
2581           </tgroup>
2582         </table>
2583       </section>
2584
2585       <section>
2586         <title>MFC 5.1 MPEG Controls</title>
2587
2588         <para>The following MPEG class controls deal with MPEG
2589 decoding and encoding settings that are specific to the Multi Format Codec 5.1 device present
2590 in the S5P family of SoCs by Samsung.
2591 </para>
2592
2593         <table pgwide="1" frame="none" id="mfc51-control-id">
2594           <title>MFC 5.1 Control IDs</title>
2595           <tgroup cols="4">
2596             <colspec colname="c1" colwidth="1*" />
2597             <colspec colname="c2" colwidth="6*" />
2598             <colspec colname="c3" colwidth="2*" />
2599             <colspec colname="c4" colwidth="6*" />
2600             <spanspec namest="c1" nameend="c2" spanname="id" />
2601             <spanspec namest="c2" nameend="c4" spanname="descr" />
2602             <thead>
2603               <row>
2604                 <entry spanname="id" align="left">ID</entry>
2605                 <entry align="left">Type</entry>
2606               </row><row><entry spanname="descr" align="left">Description</entry>
2607               </row>
2608             </thead>
2609             <tbody valign="top">
2610               <row><entry></entry></row>
2611               <row>
2612                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_DECODER_H264_DISPLAY_DELAY_ENABLE</constant>&nbsp;</entry>
2613                 <entry>integer</entry>
2614               </row><row><entry spanname="descr">If the display delay is enabled then the decoder has to return a
2615 CAPTURE buffer after processing a certain number of OUTPUT buffers. If this number is low, then it may result in
2616 buffers not being dequeued in display order. In addition hardware may still use those buffers as reference, thus
2617 application should not write to those buffers. This feature can be used for example for generating thumbnails of videos.
2618 Applicable to the H264 decoder.
2619               </entry>
2620               </row>
2621               <row><entry></entry></row>
2622               <row>
2623                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_DECODER_H264_DISPLAY_DELAY</constant>&nbsp;</entry>
2624                 <entry>integer</entry>
2625               </row><row><entry spanname="descr">Display delay value for H264 decoder.
2626 The decoder is forced to return a decoded frame after the set 'display delay' number of frames. If this number is
2627 low it may result in frames returned out of dispaly order, in addition the hardware may still be using the returned buffer
2628 as a reference picture for subsequent frames.
2629 </entry>
2630               </row>
2631               <row><entry></entry></row>
2632               <row>
2633                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_NUM_REF_PIC_FOR_P</constant>&nbsp;</entry>
2634                 <entry>integer</entry>
2635               </row><row><entry spanname="descr">The number of reference pictures used for encoding a P picture.
2636 Applicable to the H264 encoder.</entry>
2637               </row>
2638               <row><entry></entry></row>
2639               <row>
2640                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_PADDING</constant>&nbsp;</entry>
2641                 <entry>boolean</entry>
2642               </row><row><entry spanname="descr">Padding enable in the encoder - use a color instead of repeating border pixels.
2643 Applicable to encoders.</entry>
2644               </row>
2645               <row><entry></entry></row>
2646               <row>
2647                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_PADDING_YUV</constant>&nbsp;</entry>
2648                 <entry>integer</entry>
2649               </row><row><entry spanname="descr">Padding color in the encoder. Applicable to encoders. The supplied 32-bit integer is interpreted as follows (bit
2650 0 = least significant bit):</entry>
2651               </row>
2652               <row>
2653                 <entrytbl spanname="descr" cols="2">
2654                   <tbody valign="top">
2655                     <row>
2656                       <entry>Bit 0:7</entry>
2657                       <entry>V chrominance information</entry>
2658                     </row>
2659                     <row>
2660                       <entry>Bit 8:15</entry>
2661                       <entry>U chrominance information</entry>
2662                     </row>
2663                     <row>
2664                       <entry>Bit 16:23</entry>
2665                       <entry>Y luminance information</entry>
2666                     </row>
2667                     <row>
2668                       <entry>Bit 24:31</entry>
2669                       <entry>Must be zero.</entry>
2670                     </row>
2671                   </tbody>
2672                 </entrytbl>
2673               </row>
2674               <row><entry></entry></row>
2675               <row>
2676                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_RC_REACTION_COEFF</constant>&nbsp;</entry>
2677                 <entry>integer</entry>
2678               </row><row><entry spanname="descr">Reaction coefficient for MFC rate control. Applicable to encoders.
2679 <para>Note 1: Valid only when the frame level RC is enabled.</para>
2680 <para>Note 2: For tight CBR, this field must be small (ex. 2 ~ 10).
2681 For VBR, this field must be large (ex. 100 ~ 1000).</para>
2682 <para>Note 3: It is not recommended to use the greater number than FRAME_RATE * (10^9 / BIT_RATE).</para>
2683 </entry>
2684               </row>
2685               <row><entry></entry></row>
2686               <row>
2687                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_DARK</constant>&nbsp;</entry>
2688                 <entry>boolean</entry>
2689               </row><row><entry spanname="descr">Adaptive rate control for dark region.
2690 Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2691 Applicable to the H264 encoder.</entry>
2692               </row>
2693               <row><entry></entry></row>
2694               <row>
2695                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_SMOOTH</constant>&nbsp;</entry>
2696                 <entry>boolean</entry>
2697               </row><row><entry spanname="descr">Adaptive rate control for smooth region.
2698 Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2699 Applicable to the H264 encoder.</entry>
2700               </row>
2701               <row><entry></entry></row>
2702               <row>
2703                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_STATIC</constant>&nbsp;</entry>
2704                 <entry>boolean</entry>
2705               </row><row><entry spanname="descr">Adaptive rate control for static region.
2706 Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2707 Applicable to the H264 encoder.</entry>
2708               </row>
2709               <row><entry></entry></row>
2710               <row>
2711                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_ACTIVITY</constant>&nbsp;</entry>
2712                 <entry>boolean</entry>
2713               </row><row><entry spanname="descr">Adaptive rate control for activity region.
2714 Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2715 Applicable to the H264 encoder.</entry>
2716               </row>
2717               <row><entry></entry></row>
2718               <row id="v4l2-mpeg-mfc51-video-frame-skip-mode">
2719                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_FRAME_SKIP_MODE</constant>&nbsp;</entry>
2720                 <entry>enum&nbsp;v4l2_mpeg_mfc51_video_frame_skip_mode</entry>
2721               </row>
2722               <row><entry spanname="descr">
2723 Indicates in what conditions the encoder should skip frames. If encoding a frame would cause the encoded stream to be larger then
2724 a chosen data limit then the frame will be skipped.
2725 Possible values are:</entry>
2726               </row>
2727               <row>
2728                 <entrytbl spanname="descr" cols="2">
2729                   <tbody valign="top">
2730                     <row>
2731                       <entry><constant>V4L2_MPEG_MFC51_FRAME_SKIP_MODE_DISABLED</constant>&nbsp;</entry>
2732                       <entry>Frame skip mode is disabled.</entry>
2733                     </row>
2734                     <row>
2735                       <entry><constant>V4L2_MPEG_MFC51_FRAME_SKIP_MODE_LEVEL_LIMIT</constant>&nbsp;</entry>
2736                       <entry>Frame skip mode enabled and buffer limit is set by the chosen level and is defined by the standard.</entry>
2737                     </row>
2738                     <row>
2739                       <entry><constant>V4L2_MPEG_MFC51_FRAME_SKIP_MODE_BUF_LIMIT</constant>&nbsp;</entry>
2740                       <entry>Frame skip mode enabled and buffer limit is set by the VBV (MPEG1/2/4) or CPB (H264) buffer size control.</entry>
2741                     </row>
2742                   </tbody>
2743                 </entrytbl>
2744               </row>
2745               <row><entry></entry></row>
2746               <row>
2747                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_RC_FIXED_TARGET_BIT</constant>&nbsp;</entry>
2748                 <entry>integer</entry>
2749               </row><row><entry spanname="descr">Enable rate-control with fixed target bit.
2750 If this setting is enabled, then the rate control logic of the encoder will calculate the average bitrate
2751 for a GOP and keep it below or equal the set bitrate target. Otherwise the rate control logic calculates the
2752 overall average bitrate for the stream and keeps it below or equal to the set bitrate. In the first case
2753 the average bitrate for the whole stream will be smaller then the set bitrate. This is caused because the
2754 average is calculated for smaller number of frames, on the other hand enabling this setting will ensure that
2755 the stream will meet tight bandwidth contraints. Applicable to encoders.
2756 </entry>
2757               </row>
2758               <row><entry></entry></row>
2759               <row id="v4l2-mpeg-mfc51-video-force-frame-type">
2760                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_FORCE_FRAME_TYPE</constant>&nbsp;</entry>
2761                 <entry>enum&nbsp;v4l2_mpeg_mfc51_video_force_frame_type</entry>
2762               </row>
2763               <row><entry spanname="descr">Force a frame type for the next queued buffer. Applicable to encoders.
2764 Possible values are:</entry>
2765               </row>
2766               <row>
2767                 <entrytbl spanname="descr" cols="2">
2768                   <tbody valign="top">
2769                     <row>
2770                       <entry><constant>V4L2_MPEG_MFC51_FORCE_FRAME_TYPE_DISABLED</constant>&nbsp;</entry>
2771                       <entry>Forcing a specific frame type disabled.</entry>
2772                     </row>
2773                     <row>
2774                       <entry><constant>V4L2_MPEG_MFC51_FORCE_FRAME_TYPE_I_FRAME</constant>&nbsp;</entry>
2775                       <entry>Force an I-frame.</entry>
2776                     </row>
2777                     <row>
2778                       <entry><constant>V4L2_MPEG_MFC51_FORCE_FRAME_TYPE_NOT_CODED</constant>&nbsp;</entry>
2779                       <entry>Force a non-coded frame.</entry>
2780                     </row>
2781                   </tbody>
2782                 </entrytbl>
2783               </row>
2784             </tbody>
2785           </tgroup>
2786         </table>
2787       </section>
2788
2789       <section>
2790         <title>CX2341x MPEG Controls</title>
2791
2792         <para>The following MPEG class controls deal with MPEG
2793 encoding settings that are specific to the Conexant CX23415 and
2794 CX23416 MPEG encoding chips.</para>
2795
2796         <table pgwide="1" frame="none" id="cx2341x-control-id">
2797           <title>CX2341x Control IDs</title>
2798           <tgroup cols="4">
2799             <colspec colname="c1" colwidth="1*" />
2800             <colspec colname="c2" colwidth="6*" />
2801             <colspec colname="c3" colwidth="2*" />
2802             <colspec colname="c4" colwidth="6*" />
2803             <spanspec namest="c1" nameend="c2" spanname="id" />
2804             <spanspec namest="c2" nameend="c4" spanname="descr" />
2805             <thead>
2806               <row>
2807                 <entry spanname="id" align="left">ID</entry>
2808                 <entry align="left">Type</entry>
2809               </row><row><entry spanname="descr" align="left">Description</entry>
2810               </row>
2811             </thead>
2812             <tbody valign="top">
2813               <row><entry></entry></row>
2814               <row id="v4l2-mpeg-cx2341x-video-spatial-filter-mode">
2815                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_SPATIAL_FILTER_MODE</constant>&nbsp;</entry>
2816                 <entry>enum&nbsp;v4l2_mpeg_cx2341x_video_spatial_filter_mode</entry>
2817               </row><row><entry spanname="descr">Sets the Spatial
2818 Filter mode (default <constant>MANUAL</constant>). Possible values
2819 are:</entry>
2820               </row>
2821               <row>
2822                 <entrytbl spanname="descr" cols="2">
2823                   <tbody valign="top">
2824                     <row>
2825                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_SPATIAL_FILTER_MODE_MANUAL</constant>&nbsp;</entry>
2826                       <entry>Choose the filter manually</entry>
2827                     </row>
2828                     <row>
2829                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_SPATIAL_FILTER_MODE_AUTO</constant>&nbsp;</entry>
2830                       <entry>Choose the filter automatically</entry>
2831                     </row>
2832                   </tbody>
2833                 </entrytbl>
2834               </row>
2835               <row><entry></entry></row>
2836               <row>
2837                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_SPATIAL_FILTER</constant>&nbsp;</entry>
2838                 <entry>integer&nbsp;(0-15)</entry>
2839               </row><row><entry spanname="descr">The setting for the
2840 Spatial Filter. 0 = off, 15 = maximum. (Default is 0.)</entry>
2841               </row>
2842               <row><entry></entry></row>
2843               <row id="luma-spatial-filter-type">
2844                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE</constant>&nbsp;</entry>
2845                 <entry>enum&nbsp;v4l2_mpeg_cx2341x_video_luma_spatial_filter_type</entry>
2846               </row><row><entry spanname="descr">Select the algorithm
2847 to use for the Luma Spatial Filter (default
2848 <constant>1D_HOR</constant>). Possible values:</entry>
2849               </row>
2850               <row>
2851                 <entrytbl spanname="descr" cols="2">
2852                   <tbody valign="top">
2853                     <row>
2854                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_OFF</constant>&nbsp;</entry>
2855                       <entry>No filter</entry>
2856                     </row>
2857                     <row>
2858                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_1D_HOR</constant>&nbsp;</entry>
2859                       <entry>One-dimensional horizontal</entry>
2860                     </row>
2861                     <row>
2862                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_1D_VERT</constant>&nbsp;</entry>
2863                       <entry>One-dimensional vertical</entry>
2864                     </row>
2865                     <row>
2866                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_2D_HV_SEPARABLE</constant>&nbsp;</entry>
2867                       <entry>Two-dimensional separable</entry>
2868                     </row>
2869                     <row>
2870                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_2D_SYM_NON_SEPARABLE</constant>&nbsp;</entry>
2871                       <entry>Two-dimensional symmetrical
2872 non-separable</entry>
2873                     </row>
2874                   </tbody>
2875                 </entrytbl>
2876               </row>
2877               <row><entry></entry></row>
2878               <row id="chroma-spatial-filter-type">
2879                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_CHROMA_SPATIAL_FILTER_TYPE</constant>&nbsp;</entry>
2880                 <entry>enum&nbsp;v4l2_mpeg_cx2341x_video_chroma_spatial_filter_type</entry>
2881               </row><row><entry spanname="descr">Select the algorithm
2882 for the Chroma Spatial Filter (default <constant>1D_HOR</constant>).
2883 Possible values are:</entry>
2884               </row>
2885               <row>
2886                 <entrytbl spanname="descr" cols="2">
2887                   <tbody valign="top">
2888                     <row>
2889                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_CHROMA_SPATIAL_FILTER_TYPE_OFF</constant>&nbsp;</entry>
2890                       <entry>No filter</entry>
2891                     </row>
2892                     <row>
2893                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_CHROMA_SPATIAL_FILTER_TYPE_1D_HOR</constant>&nbsp;</entry>
2894                       <entry>One-dimensional horizontal</entry>
2895                     </row>
2896                   </tbody>
2897                 </entrytbl>
2898               </row>
2899               <row><entry></entry></row>
2900               <row id="v4l2-mpeg-cx2341x-video-temporal-filter-mode">
2901                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER_MODE</constant>&nbsp;</entry>
2902                 <entry>enum&nbsp;v4l2_mpeg_cx2341x_video_temporal_filter_mode</entry>
2903               </row><row><entry spanname="descr">Sets the Temporal
2904 Filter mode (default <constant>MANUAL</constant>). Possible values
2905 are:</entry>
2906               </row>
2907               <row>
2908                 <entrytbl spanname="descr" cols="2">
2909                   <tbody valign="top">
2910                     <row>
2911                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER_MODE_MANUAL</constant>&nbsp;</entry>
2912                       <entry>Choose the filter manually</entry>
2913                     </row>
2914                     <row>
2915                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER_MODE_AUTO</constant>&nbsp;</entry>
2916                       <entry>Choose the filter automatically</entry>
2917                     </row>
2918                   </tbody>
2919                 </entrytbl>
2920               </row>
2921               <row><entry></entry></row>
2922               <row>
2923                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER</constant>&nbsp;</entry>
2924                 <entry>integer&nbsp;(0-31)</entry>
2925               </row><row><entry spanname="descr">The setting for the
2926 Temporal Filter. 0 = off, 31 = maximum. (Default is 8 for full-scale
2927 capturing and 0 for scaled capturing.)</entry>
2928               </row>
2929               <row><entry></entry></row>
2930               <row id="v4l2-mpeg-cx2341x-video-median-filter-type">
2931                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE</constant>&nbsp;</entry>
2932                 <entry>enum&nbsp;v4l2_mpeg_cx2341x_video_median_filter_type</entry>
2933               </row><row><entry spanname="descr">Median Filter Type
2934 (default <constant>OFF</constant>). Possible values are:</entry>
2935               </row>
2936               <row>
2937                 <entrytbl spanname="descr" cols="2">
2938                   <tbody valign="top">
2939                     <row>
2940                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_OFF</constant>&nbsp;</entry>
2941                       <entry>No filter</entry>
2942                     </row>
2943                     <row>
2944                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_HOR</constant>&nbsp;</entry>
2945                       <entry>Horizontal filter</entry>
2946                     </row>
2947                     <row>
2948                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_VERT</constant>&nbsp;</entry>
2949                       <entry>Vertical filter</entry>
2950                     </row>
2951                     <row>
2952                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_HOR_VERT</constant>&nbsp;</entry>
2953                       <entry>Horizontal and vertical filter</entry>
2954                     </row>
2955                     <row>
2956                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_DIAG</constant>&nbsp;</entry>
2957                       <entry>Diagonal filter</entry>
2958                     </row>
2959                   </tbody>
2960                 </entrytbl>
2961               </row>
2962               <row><entry></entry></row>
2963               <row>
2964                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_LUMA_MEDIAN_FILTER_BOTTOM</constant>&nbsp;</entry>
2965                 <entry>integer&nbsp;(0-255)</entry>
2966               </row><row><entry spanname="descr">Threshold above which
2967 the luminance median filter is enabled (default 0)</entry>
2968               </row>
2969               <row><entry></entry></row>
2970               <row>
2971                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_LUMA_MEDIAN_FILTER_TOP</constant>&nbsp;</entry>
2972                 <entry>integer&nbsp;(0-255)</entry>
2973               </row><row><entry spanname="descr">Threshold below which
2974 the luminance median filter is enabled (default 255)</entry>
2975               </row>
2976               <row><entry></entry></row>
2977               <row>
2978                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_CHROMA_MEDIAN_FILTER_BOTTOM</constant>&nbsp;</entry>
2979                 <entry>integer&nbsp;(0-255)</entry>
2980               </row><row><entry spanname="descr">Threshold above which
2981 the chroma median filter is enabled (default 0)</entry>
2982               </row>
2983               <row><entry></entry></row>
2984               <row>
2985                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_CHROMA_MEDIAN_FILTER_TOP</constant>&nbsp;</entry>
2986                 <entry>integer&nbsp;(0-255)</entry>
2987               </row><row><entry spanname="descr">Threshold below which
2988 the chroma median filter is enabled (default 255)</entry>
2989               </row>
2990               <row><entry></entry></row>
2991               <row>
2992                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_STREAM_INSERT_NAV_PACKETS</constant>&nbsp;</entry>
2993                 <entry>boolean</entry>
2994               </row>
2995               <row><entry spanname="descr">The CX2341X MPEG encoder
2996 can insert one empty MPEG-2 PES packet into the stream between every
2997 four video frames. The packet size is 2048 bytes, including the
2998 packet_start_code_prefix and stream_id fields. The stream_id is 0xBF
2999 (private stream 2). The payload consists of 0x00 bytes, to be filled
3000 in by the application. 0 = do not insert, 1 = insert packets.</entry>
3001               </row>
3002             </tbody>
3003           </tgroup>
3004         </table>
3005       </section>
3006     </section>
3007
3008     <section id="camera-controls">
3009       <title>Camera Control Reference</title>
3010
3011       <para>The Camera class includes controls for mechanical (or
3012 equivalent digital) features of a device such as controllable lenses
3013 or sensors.</para>
3014
3015     <table pgwide="1" frame="none" id="camera-control-id">
3016       <title>Camera Control IDs</title>
3017       <tgroup cols="4">
3018         <colspec colname="c1" colwidth="1*" />
3019         <colspec colname="c2" colwidth="6*" />
3020         <colspec colname="c3" colwidth="2*" />
3021         <colspec colname="c4" colwidth="6*" />
3022         <spanspec namest="c1" nameend="c2" spanname="id" />
3023         <spanspec namest="c2" nameend="c4" spanname="descr" />
3024         <thead>
3025           <row>
3026             <entry spanname="id" align="left">ID</entry>
3027             <entry align="left">Type</entry>
3028           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
3029           </row>
3030         </thead>
3031         <tbody valign="top">
3032           <row><entry></entry></row>
3033           <row>
3034             <entry spanname="id"><constant>V4L2_CID_CAMERA_CLASS</constant>&nbsp;</entry>
3035             <entry>class</entry>
3036           </row><row><entry spanname="descr">The Camera class
3037 descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
3038 description of this control class.</entry>
3039           </row>
3040           <row><entry></entry></row>
3041
3042           <row id="v4l2-exposure-auto-type">
3043             <entry spanname="id"><constant>V4L2_CID_EXPOSURE_AUTO</constant>&nbsp;</entry>
3044             <entry>enum&nbsp;v4l2_exposure_auto_type</entry>
3045           </row><row><entry spanname="descr">Enables automatic
3046 adjustments of the exposure time and/or iris aperture. The effect of
3047 manual changes of the exposure time or iris aperture while these
3048 features are enabled is undefined, drivers should ignore such
3049 requests. Possible values are:</entry>
3050           </row>
3051           <row>
3052             <entrytbl spanname="descr" cols="2">
3053               <tbody valign="top">
3054                 <row>
3055                   <entry><constant>V4L2_EXPOSURE_AUTO</constant>&nbsp;</entry>
3056                       <entry>Automatic exposure time, automatic iris
3057 aperture.</entry>
3058                 </row>
3059                 <row>
3060                   <entry><constant>V4L2_EXPOSURE_MANUAL</constant>&nbsp;</entry>
3061                   <entry>Manual exposure time, manual iris.</entry>
3062                 </row>
3063                 <row>
3064                   <entry><constant>V4L2_EXPOSURE_SHUTTER_PRIORITY</constant>&nbsp;</entry>
3065                   <entry>Manual exposure time, auto iris.</entry>
3066                 </row>
3067                 <row>
3068                   <entry><constant>V4L2_EXPOSURE_APERTURE_PRIORITY</constant>&nbsp;</entry>
3069                   <entry>Auto exposure time, manual iris.</entry>
3070                 </row>
3071               </tbody>
3072             </entrytbl>
3073           </row>
3074           <row><entry></entry></row>
3075
3076           <row>
3077             <entry spanname="id"><constant>V4L2_CID_EXPOSURE_ABSOLUTE</constant>&nbsp;</entry>
3078             <entry>integer</entry>
3079           </row><row><entry spanname="descr">Determines the exposure
3080 time of the camera sensor. The exposure time is limited by the frame
3081 interval. Drivers should interpret the values as 100 &micro;s units,
3082 where the value 1 stands for 1/10000th of a second, 10000 for 1 second
3083 and 100000 for 10 seconds.</entry>
3084           </row>
3085           <row><entry></entry></row>
3086
3087           <row>
3088             <entry spanname="id"><constant>V4L2_CID_EXPOSURE_AUTO_PRIORITY</constant>&nbsp;</entry>
3089             <entry>boolean</entry>
3090           </row><row><entry spanname="descr">When
3091 <constant>V4L2_CID_EXPOSURE_AUTO</constant> is set to
3092 <constant>AUTO</constant> or <constant>APERTURE_PRIORITY</constant>,
3093 this control determines if the device may dynamically vary the frame
3094 rate. By default this feature is disabled (0) and the frame rate must
3095 remain constant.</entry>
3096           </row>
3097           <row><entry></entry></row>
3098
3099           <row>
3100             <entry spanname="id"><constant>V4L2_CID_EXPOSURE_BIAS</constant>&nbsp;</entry>
3101             <entry>integer menu</entry>
3102           </row><row><entry spanname="descr"> Determines the automatic
3103 exposure compensation, it is effective only when <constant>V4L2_CID_EXPOSURE_AUTO</constant>
3104 control is set to <constant>AUTO</constant>, <constant>SHUTTER_PRIORITY </constant>
3105 or <constant>APERTURE_PRIORITY</constant>.
3106 It is expressed in terms of EV, drivers should interpret the values as 0.001 EV
3107 units, where the value 1000 stands for +1 EV.
3108 <para>Increasing the exposure compensation value is equivalent to decreasing
3109 the exposure value (EV) and will increase the amount of light at the image
3110 sensor. The camera performs the exposure compensation by adjusting absolute
3111 exposure time and/or aperture.</para></entry>
3112           </row>
3113           <row><entry></entry></row>
3114
3115           <row id="v4l2-exposure-metering">
3116             <entry spanname="id"><constant>V4L2_CID_EXPOSURE_METERING</constant>&nbsp;</entry>
3117             <entry>enum&nbsp;v4l2_exposure_metering</entry>
3118           </row><row><entry spanname="descr">Determines how the camera measures
3119 the amount of light available for the frame exposure. Possible values are:</entry>
3120           </row>
3121           <row>
3122             <entrytbl spanname="descr" cols="2">
3123               <tbody valign="top">
3124                 <row>
3125                   <entry><constant>V4L2_EXPOSURE_METERING_AVERAGE</constant>&nbsp;</entry>
3126                   <entry>Use the light information coming from the entire frame
3127 and average giving no weighting to any particular portion of the metered area.
3128                   </entry>
3129                 </row>
3130                 <row>
3131                   <entry><constant>V4L2_EXPOSURE_METERING_CENTER_WEIGHTED</constant>&nbsp;</entry>
3132                   <entry>Average the light information coming from the entire frame
3133 giving priority to the center of the metered area.</entry>
3134                 </row>
3135                 <row>
3136                   <entry><constant>V4L2_EXPOSURE_METERING_SPOT</constant>&nbsp;</entry>
3137                   <entry>Measure only very small area at the center of the frame.</entry>
3138                 </row>
3139               </tbody>
3140             </entrytbl>
3141           </row>
3142           <row><entry></entry></row>
3143
3144           <row>
3145             <entry spanname="id"><constant>V4L2_CID_PAN_RELATIVE</constant>&nbsp;</entry>
3146             <entry>integer</entry>
3147           </row><row><entry spanname="descr">This control turns the
3148 camera horizontally by the specified amount. The unit is undefined. A
3149 positive value moves the camera to the right (clockwise when viewed
3150 from above), a negative value to the left. A value of zero does not
3151 cause motion. This is a write-only control.</entry>
3152           </row>
3153           <row><entry></entry></row>
3154
3155           <row>
3156             <entry spanname="id"><constant>V4L2_CID_TILT_RELATIVE</constant>&nbsp;</entry>
3157             <entry>integer</entry>
3158           </row><row><entry spanname="descr">This control turns the
3159 camera vertically by the specified amount. The unit is undefined. A
3160 positive value moves the camera up, a negative value down. A value of
3161 zero does not cause motion. This is a write-only control.</entry>
3162           </row>
3163           <row><entry></entry></row>
3164
3165           <row>
3166             <entry spanname="id"><constant>V4L2_CID_PAN_RESET</constant>&nbsp;</entry>
3167             <entry>button</entry>
3168           </row><row><entry spanname="descr">When this control is set,
3169 the camera moves horizontally to the default position.</entry>
3170           </row>
3171           <row><entry></entry></row>
3172
3173           <row>
3174             <entry spanname="id"><constant>V4L2_CID_TILT_RESET</constant>&nbsp;</entry>
3175             <entry>button</entry>
3176           </row><row><entry spanname="descr">When this control is set,
3177 the camera moves vertically to the default position.</entry>
3178           </row>
3179           <row><entry></entry></row>
3180
3181           <row>
3182             <entry spanname="id"><constant>V4L2_CID_PAN_ABSOLUTE</constant>&nbsp;</entry>
3183             <entry>integer</entry>
3184           </row><row><entry spanname="descr">This control
3185 turns the camera horizontally to the specified position. Positive
3186 values move the camera to the right (clockwise when viewed from above),
3187 negative values to the left. Drivers should interpret the values as arc
3188 seconds, with valid values between -180 * 3600 and +180 * 3600
3189 inclusive.</entry>
3190           </row>
3191           <row><entry></entry></row>
3192
3193           <row>
3194             <entry spanname="id"><constant>V4L2_CID_TILT_ABSOLUTE</constant>&nbsp;</entry>
3195             <entry>integer</entry>
3196           </row><row><entry spanname="descr">This control
3197 turns the camera vertically to the specified position. Positive values
3198 move the camera up, negative values down. Drivers should interpret the
3199 values as arc seconds, with valid values between -180 * 3600 and +180
3200 * 3600 inclusive.</entry>
3201           </row>
3202           <row><entry></entry></row>
3203
3204           <row>
3205             <entry spanname="id"><constant>V4L2_CID_FOCUS_ABSOLUTE</constant>&nbsp;</entry>
3206             <entry>integer</entry>
3207           </row><row><entry spanname="descr">This control sets the
3208 focal point of the camera to the specified position. The unit is
3209 undefined. Positive values set the focus closer to the camera,
3210 negative values towards infinity.</entry>
3211           </row>
3212           <row><entry></entry></row>
3213
3214           <row>
3215             <entry spanname="id"><constant>V4L2_CID_FOCUS_RELATIVE</constant>&nbsp;</entry>
3216             <entry>integer</entry>
3217           </row><row><entry spanname="descr">This control moves the
3218 focal point of the camera by the specified amount. The unit is
3219 undefined. Positive values move the focus closer to the camera,
3220 negative values towards infinity. This is a write-only control.</entry>
3221           </row>
3222           <row><entry></entry></row>
3223
3224           <row>
3225             <entry spanname="id"><constant>V4L2_CID_FOCUS_AUTO</constant>&nbsp;</entry>
3226             <entry>boolean</entry>
3227           </row><row><entry spanname="descr">Enables continuous automatic
3228 focus adjustments. The effect of manual focus adjustments while this feature
3229 is enabled is undefined, drivers should ignore such requests.</entry>
3230           </row>
3231           <row><entry></entry></row>
3232
3233           <row>
3234             <entry spanname="id"><constant>V4L2_CID_AUTO_FOCUS_START</constant>&nbsp;</entry>
3235             <entry>button</entry>
3236           </row><row><entry spanname="descr">Starts single auto focus process.
3237 The effect of setting this control when <constant>V4L2_CID_FOCUS_AUTO</constant>
3238 is set to <constant>TRUE</constant> (1) is undefined, drivers should ignore
3239 such requests.</entry>
3240           </row>
3241           <row><entry></entry></row>
3242
3243           <row>
3244             <entry spanname="id"><constant>V4L2_CID_AUTO_FOCUS_STOP</constant>&nbsp;</entry>
3245             <entry>button</entry>
3246           </row><row><entry spanname="descr">Aborts automatic focusing
3247 started with <constant>V4L2_CID_AUTO_FOCUS_START</constant> control. It is
3248 effective only when the continuous autofocus is disabled, that is when
3249 <constant>V4L2_CID_FOCUS_AUTO</constant> control is set to <constant>FALSE
3250 </constant> (0).</entry>
3251           </row>
3252           <row><entry></entry></row>
3253
3254           <row id="v4l2-auto-focus-status">
3255             <entry spanname="id">
3256               <constant>V4L2_CID_AUTO_FOCUS_STATUS</constant>&nbsp;</entry>
3257             <entry>bitmask</entry>
3258           </row>
3259           <row><entry spanname="descr">The automatic focus status. This is a read-only
3260           control.</entry>
3261           </row>
3262           <row>
3263             <entrytbl spanname="descr" cols="2">
3264               <tbody valign="top">
3265                 <row>
3266                   <entry><constant>V4L2_AUTO_FOCUS_STATUS_IDLE</constant>&nbsp;</entry>
3267                   <entry>Automatic focus is not active.</entry>
3268                 </row>
3269                 <row>
3270                   <entry><constant>V4L2_AUTO_FOCUS_STATUS_BUSY</constant>&nbsp;</entry>
3271                   <entry>Automatic focusing is in progress.</entry>
3272                 </row>
3273                 <row>
3274                   <entry><constant>V4L2_AUTO_FOCUS_STATUS_REACHED</constant>&nbsp;</entry>
3275                   <entry>Focus has been reached.</entry>
3276                 </row>
3277                 <row>
3278                   <entry><constant>V4L2_AUTO_FOCUS_STATUS_FAILED</constant>&nbsp;</entry>
3279                   <entry>Automatic focus has failed, the driver will not
3280                   transition from this state until another action is
3281                   performed by an application.</entry>
3282                 </row>
3283               </tbody>
3284             </entrytbl>
3285           </row>
3286           <row><entry spanname="descr">
3287 Setting <constant>V4L2_LOCK_FOCUS</constant> lock bit of the <constant>V4L2_CID_3A_LOCK
3288 </constant> control may stop updates of the <constant>V4L2_CID_AUTO_FOCUS_STATUS</constant>
3289 control value.</entry>
3290           </row>
3291           <row><entry></entry></row>
3292
3293           <row id="v4l2-auto-focus-range">
3294             <entry spanname="id">
3295               <constant>V4L2_CID_AUTO_FOCUS_RANGE</constant>&nbsp;</entry>
3296             <entry>enum&nbsp;v4l2_auto_focus_range</entry>
3297           </row>
3298           <row><entry spanname="descr">Determines auto focus distance range
3299 for which lens may be adjusted. </entry>
3300           </row>
3301           <row>
3302             <entrytbl spanname="descr" cols="2">
3303               <tbody valign="top">
3304                 <row>
3305                   <entry><constant>V4L2_AUTO_FOCUS_RANGE_AUTO</constant>&nbsp;</entry>
3306                   <entry>The camera automatically selects the focus range.</entry>
3307                 </row>
3308                 <row>
3309                   <entry><constant>V4L2_AUTO_FOCUS_RANGE_NORMAL</constant>&nbsp;</entry>
3310                   <entry>Normal distance range, limited for best automatic focus
3311 performance.</entry>
3312                 </row>
3313                 <row>
3314                   <entry><constant>V4L2_AUTO_FOCUS_RANGE_MACRO</constant>&nbsp;</entry>
3315                   <entry>Macro (close-up) auto focus. The camera will
3316 use its minimum possible distance for auto focus.</entry>
3317                 </row>
3318                 <row>
3319                   <entry><constant>V4L2_AUTO_FOCUS_RANGE_INFINITY</constant>&nbsp;</entry>
3320                   <entry>The lens is set to focus on an object at infinite distance.</entry>
3321                 </row>
3322               </tbody>
3323             </entrytbl>
3324           </row>
3325           <row><entry></entry></row>
3326
3327           <row>
3328             <entry spanname="id"><constant>V4L2_CID_ZOOM_ABSOLUTE</constant>&nbsp;</entry>
3329             <entry>integer</entry>
3330           </row><row><entry spanname="descr">Specify the objective lens
3331 focal length as an absolute value. The zoom unit is driver-specific and its
3332 value should be a positive integer.</entry>
3333           </row>
3334           <row><entry></entry></row>
3335
3336           <row>
3337             <entry spanname="id"><constant>V4L2_CID_ZOOM_RELATIVE</constant>&nbsp;</entry>
3338             <entry>integer</entry>
3339           </row><row><entry spanname="descr">Specify the objective lens
3340 focal length relatively to the current value. Positive values move the zoom
3341 lens group towards the telephoto direction, negative values towards the
3342 wide-angle direction. The zoom unit is driver-specific. This is a write-only control.</entry>
3343           </row>
3344           <row><entry></entry></row>
3345
3346           <row>
3347             <entry spanname="id"><constant>V4L2_CID_ZOOM_CONTINUOUS</constant>&nbsp;</entry>
3348             <entry>integer</entry>
3349           </row><row><entry spanname="descr">Move the objective lens group
3350 at the specified speed until it reaches physical device limits or until an
3351 explicit request to stop the movement. A positive value moves the zoom lens
3352 group towards the telephoto direction. A value of zero stops the zoom lens
3353 group movement. A negative value moves the zoom lens group towards the
3354 wide-angle direction. The zoom speed unit is driver-specific.</entry>
3355           </row>
3356           <row><entry></entry></row>
3357
3358           <row>
3359             <entry spanname="id"><constant>V4L2_CID_IRIS_ABSOLUTE</constant>&nbsp;</entry>
3360             <entry>integer</entry>
3361           </row><row><entry spanname="descr">This control sets the
3362 camera's aperture to the specified value. The unit is undefined.
3363 Larger values open the iris wider, smaller values close it.</entry>
3364           </row>
3365           <row><entry></entry></row>
3366
3367           <row>
3368             <entry spanname="id"><constant>V4L2_CID_IRIS_RELATIVE</constant>&nbsp;</entry>
3369             <entry>integer</entry>
3370           </row><row><entry spanname="descr">This control modifies the
3371 camera's aperture by the specified amount. The unit is undefined.
3372 Positive values open the iris one step further, negative values close
3373 it one step further. This is a write-only control.</entry>
3374           </row>
3375           <row><entry></entry></row>
3376
3377           <row>
3378             <entry spanname="id"><constant>V4L2_CID_PRIVACY</constant>&nbsp;</entry>
3379             <entry>boolean</entry>
3380           </row><row><entry spanname="descr">Prevent video from being acquired
3381 by the camera. When this control is set to <constant>TRUE</constant> (1), no
3382 image can be captured by the camera. Common means to enforce privacy are
3383 mechanical obturation of the sensor and firmware image processing, but the
3384 device is not restricted to these methods. Devices that implement the privacy
3385 control must support read access and may support write access.</entry>
3386           </row>
3387
3388           <row>
3389             <entry spanname="id"><constant>V4L2_CID_BAND_STOP_FILTER</constant>&nbsp;</entry>
3390             <entry>integer</entry>
3391           </row><row><entry spanname="descr">Switch the band-stop filter of a
3392 camera sensor on or off, or specify its strength. Such band-stop filters can
3393 be used, for example, to filter out the fluorescent light component.</entry>
3394           </row>
3395           <row><entry></entry></row>
3396
3397           <row id="v4l2-auto-n-preset-white-balance">
3398             <entry spanname="id"><constant>V4L2_CID_AUTO_N_PRESET_WHITE_BALANCE</constant>&nbsp;</entry>
3399             <entry>enum&nbsp;v4l2_auto_n_preset_white_balance</entry>
3400           </row><row><entry spanname="descr">Sets white balance to automatic,
3401 manual or a preset. The presets determine color temperature of the light as
3402 a hint to the camera for white balance adjustments resulting in most accurate
3403 color representation. The following white balance presets are listed in order
3404 of increasing color temperature.</entry>
3405           </row>
3406           <row>
3407             <entrytbl spanname="descr" cols="2">
3408               <tbody valign="top">
3409                 <row>
3410                   <entry><constant>V4L2_WHITE_BALANCE_MANUAL</constant>&nbsp;</entry>
3411                   <entry>Manual white balance.</entry>
3412                 </row>
3413                 <row>
3414                   <entry><constant>V4L2_WHITE_BALANCE_AUTO</constant>&nbsp;</entry>
3415                   <entry>Automatic white balance adjustments.</entry>
3416                 </row>
3417                 <row>
3418                   <entry><constant>V4L2_WHITE_BALANCE_INCANDESCENT</constant>&nbsp;</entry>
3419                   <entry>White balance setting for incandescent (tungsten) lighting.
3420 It generally cools down the colors and corresponds approximately to 2500...3500 K
3421 color temperature range.</entry>
3422                 </row>
3423                 <row>
3424                   <entry><constant>V4L2_WHITE_BALANCE_FLUORESCENT</constant>&nbsp;</entry>
3425                   <entry>White balance preset for fluorescent lighting.
3426 It corresponds approximately to 4000...5000 K color temperature.</entry>
3427                 </row>
3428                 <row>
3429                   <entry><constant>V4L2_WHITE_BALANCE_FLUORESCENT_H</constant>&nbsp;</entry>
3430                   <entry>With this setting the camera will compensate for
3431 fluorescent H lighting.</entry>
3432                 </row>
3433                 <row>
3434                   <entry><constant>V4L2_WHITE_BALANCE_HORIZON</constant>&nbsp;</entry>
3435                   <entry>White balance setting for horizon daylight.
3436 It corresponds approximately to 5000 K color temperature.</entry>
3437                 </row>
3438                 <row>
3439                   <entry><constant>V4L2_WHITE_BALANCE_DAYLIGHT</constant>&nbsp;</entry>
3440                   <entry>White balance preset for daylight (with clear sky).
3441 It corresponds approximately to 5000...6500 K color temperature.</entry>
3442                 </row>
3443                 <row>
3444                   <entry><constant>V4L2_WHITE_BALANCE_FLASH</constant>&nbsp;</entry>
3445                   <entry>With this setting the camera will compensate for the flash
3446 light. It slightly warms up the colors and corresponds roughly to 5000...5500 K
3447 color temperature.</entry>
3448                 </row>
3449                 <row>
3450                   <entry><constant>V4L2_WHITE_BALANCE_CLOUDY</constant>&nbsp;</entry>
3451                   <entry>White balance preset for moderately overcast sky.
3452 This option corresponds approximately to 6500...8000 K color temperature
3453 range.</entry>
3454                 </row>
3455                 <row>
3456                   <entry><constant>V4L2_WHITE_BALANCE_SHADE</constant>&nbsp;</entry>
3457                   <entry>White balance preset for shade or heavily overcast
3458 sky. It corresponds approximately to 9000...10000 K color temperature.
3459 </entry>
3460                 </row>
3461               </tbody>
3462             </entrytbl>
3463           </row>
3464           <row><entry></entry></row>
3465
3466           <row id="v4l2-wide-dynamic-range">
3467             <entry spanname="id"><constant>V4L2_CID_WIDE_DYNAMIC_RANGE</constant></entry>
3468             <entry>boolean</entry>
3469           </row>
3470           <row>
3471             <entry spanname="descr">Enables or disables the camera's wide dynamic
3472 range feature. This feature allows to obtain clear images in situations where
3473 intensity of the illumination varies significantly throughout the scene, i.e.
3474 there are simultaneously very dark and very bright areas. It is most commonly
3475 realized in cameras by combining two subsequent frames with different exposure
3476 times. <footnote id="ctypeconv"><para> This control may be changed to a menu
3477 control in the future, if more options are required.</para></footnote></entry>
3478           </row>
3479           <row><entry></entry></row>
3480
3481           <row id="v4l2-image-stabilization">
3482             <entry spanname="id"><constant>V4L2_CID_IMAGE_STABILIZATION</constant></entry>
3483             <entry>boolean</entry>
3484           </row>
3485           <row>
3486             <entry spanname="descr">Enables or disables image stabilization.
3487               <footnoteref linkend="ctypeconv"/></entry>
3488           </row>
3489           <row><entry></entry></row>
3490
3491           <row>
3492             <entry spanname="id"><constant>V4L2_CID_ISO_SENSITIVITY</constant>&nbsp;</entry>
3493             <entry>integer menu</entry>
3494           </row><row><entry spanname="descr">Determines ISO equivalent of an
3495 image sensor indicating the sensor's sensitivity to light. The numbers are
3496 expressed in arithmetic scale, as per <xref linkend="iso12232" /> standard,
3497 where doubling the sensor sensitivity is represented by doubling the numerical
3498 ISO value. Applications should interpret the values as standard ISO values
3499 multiplied by 1000, e.g. control value 800 stands for ISO 0.8. Drivers will
3500 usually support only a subset of standard ISO values. The effect of setting
3501 this control while the <constant>V4L2_CID_ISO_SENSITIVITY_AUTO</constant>
3502 control is set to a value other than <constant>V4L2_CID_ISO_SENSITIVITY_MANUAL
3503 </constant> is undefined, drivers should ignore such requests.</entry>
3504           </row>
3505           <row><entry></entry></row>
3506
3507           <row id="v4l2-iso-sensitivity-auto-type">
3508             <entry spanname="id"><constant>V4L2_CID_ISO_SENSITIVITY_AUTO</constant>&nbsp;</entry>
3509             <entry>enum&nbsp;v4l2_iso_sensitivity_type</entry>
3510           </row><row><entry spanname="descr">Enables or disables automatic ISO
3511 sensitivity adjustments.</entry>
3512           </row>
3513           <row>
3514             <entrytbl spanname="descr" cols="2">
3515               <tbody valign="top">
3516                 <row>
3517                   <entry><constant>V4L2_CID_ISO_SENSITIVITY_MANUAL</constant>&nbsp;</entry>
3518                   <entry>Manual ISO sensitivity.</entry>
3519                 </row>
3520                 <row>
3521                   <entry><constant>V4L2_CID_ISO_SENSITIVITY_AUTO</constant>&nbsp;</entry>
3522                   <entry>Automatic ISO sensitivity adjustments.</entry>
3523                 </row>
3524               </tbody>
3525             </entrytbl>
3526           </row>
3527           <row><entry></entry></row>
3528
3529           <row id="v4l2-scene-mode">
3530             <entry spanname="id"><constant>V4L2_CID_SCENE_MODE</constant>&nbsp;</entry>
3531             <entry>enum&nbsp;v4l2_scene_mode</entry>
3532           </row><row><entry spanname="descr">This control allows to select
3533 scene programs as the camera automatic modes optimized for common shooting
3534 scenes. Within these modes the camera determines best exposure, aperture,
3535 focusing, light metering, white balance and equivalent sensitivity. The
3536 controls of those parameters are influenced by the scene mode control.
3537 An exact behavior in each mode is subject to the camera specification.
3538
3539 <para>When the scene mode feature is not used, this control should be set to
3540 <constant>V4L2_SCENE_MODE_NONE</constant> to make sure the other possibly
3541 related controls are accessible. The following scene programs are defined:
3542 </para>
3543 </entry>
3544           </row>
3545           <row>
3546             <entrytbl spanname="descr" cols="2">
3547               <tbody valign="top">
3548                 <row>
3549                   <entry><constant>V4L2_SCENE_MODE_NONE</constant>&nbsp;</entry>
3550                   <entry>The scene mode feature is disabled.</entry>
3551                 </row>
3552                 <row>
3553                   <entry><constant>V4L2_SCENE_MODE_BACKLIGHT</constant>&nbsp;</entry>
3554                   <entry>Backlight. Compensates for dark shadows when light is
3555                   coming from behind a subject, also by automatically turning
3556                   on the flash.</entry>
3557                 </row>
3558                 <row>
3559                   <entry><constant>V4L2_SCENE_MODE_BEACH_SNOW</constant>&nbsp;</entry>
3560                   <entry>Beach and snow. This mode compensates for all-white or
3561 bright scenes, which tend to look gray and low contrast, when camera's automatic
3562 exposure is based on an average scene brightness. To compensate, this mode
3563 automatically slightly overexposes the frames. The white balance may also be
3564 adjusted to compensate for the fact that reflected snow looks bluish rather
3565 than white.</entry>
3566                 </row>
3567                 <row>
3568                   <entry><constant>V4L2_SCENE_MODE_CANDLELIGHT</constant>&nbsp;</entry>
3569                   <entry>Candle light. The camera generally raises the ISO
3570 sensitivity and lowers the shutter speed. This mode compensates for relatively
3571 close subject in the scene. The flash is disabled in order to preserve the
3572 ambiance of the light.</entry>
3573                 </row>
3574                 <row>
3575                   <entry><constant>V4L2_SCENE_MODE_DAWN_DUSK</constant>&nbsp;</entry>
3576                   <entry>Dawn and dusk. Preserves the colors seen in low
3577 natural light before dusk and after down. The camera may turn off the flash,
3578 and automatically focus at infinity. It will usually boost saturation and
3579 lower the shutter speed.</entry>
3580                 </row>
3581                 <row>
3582                   <entry><constant>V4L2_SCENE_MODE_FALL_COLORS</constant>&nbsp;</entry>
3583                   <entry>Fall colors. Increases saturation and adjusts white
3584 balance for color enhancement. Pictures of autumn leaves get saturated reds
3585 and yellows.</entry>
3586                 </row>
3587                 <row>
3588                   <entry><constant>V4L2_SCENE_MODE_FIREWORKS</constant>&nbsp;</entry>
3589                   <entry>Fireworks. Long exposure times are used to capture
3590 the expanding burst of light from a firework. The camera may invoke image
3591 stabilization.</entry>
3592                 </row>
3593                 <row>
3594                   <entry><constant>V4L2_SCENE_MODE_LANDSCAPE</constant>&nbsp;</entry>
3595                   <entry>Landscape. The camera may choose a small aperture to
3596 provide deep depth of field and long exposure duration to help capture detail
3597 in dim light conditions. The focus is fixed at infinity. Suitable for distant
3598 and wide scenery.</entry>
3599                 </row>
3600                 <row>
3601                   <entry><constant>V4L2_SCENE_MODE_NIGHT</constant>&nbsp;</entry>
3602                   <entry>Night, also known as Night Landscape. Designed for low
3603 light conditions, it preserves detail in the dark areas without blowing out bright
3604 objects. The camera generally sets itself to a medium-to-high ISO sensitivity,
3605 with a relatively long exposure time, and turns flash off. As such, there will be
3606 increased image noise and the possibility of blurred image.</entry>
3607                 </row>
3608                 <row>
3609                   <entry><constant>V4L2_SCENE_MODE_PARTY_INDOOR</constant>&nbsp;</entry>
3610                   <entry>Party and indoor. Designed to capture indoor scenes
3611 that are lit by indoor background lighting as well as the flash. The camera
3612 usually increases ISO sensitivity, and adjusts exposure for the low light
3613 conditions.</entry>
3614                 </row>
3615                 <row>
3616                   <entry><constant>V4L2_SCENE_MODE_PORTRAIT</constant>&nbsp;</entry>
3617                   <entry>Portrait. The camera adjusts the aperture so that the
3618 depth of field is reduced, which helps to isolate the subject against a smooth
3619 background. Most cameras recognize the presence of faces in the scene and focus
3620 on them. The color hue is adjusted to enhance skin tones. The intensity of the
3621 flash is often reduced.</entry>
3622                 </row>
3623                 <row>
3624                   <entry><constant>V4L2_SCENE_MODE_SPORTS</constant>&nbsp;</entry>
3625                   <entry>Sports. Significantly increases ISO and uses a fast
3626 shutter speed to freeze motion of rapidly-moving subjects. Increased image
3627 noise may be seen in this mode.</entry>
3628                 </row>
3629                 <row>
3630                   <entry><constant>V4L2_SCENE_MODE_SUNSET</constant>&nbsp;</entry>
3631                   <entry>Sunset. Preserves deep hues seen in sunsets and
3632 sunrises. It bumps up the saturation.</entry>
3633                 </row>
3634                 <row>
3635                   <entry><constant>V4L2_SCENE_MODE_TEXT</constant>&nbsp;</entry>
3636                   <entry>Text. It applies extra contrast and sharpness, it is
3637 typically a black-and-white mode optimized for readability. Automatic focus
3638 may be switched to close-up mode and this setting may also involve some
3639 lens-distortion correction.</entry>
3640                 </row>
3641               </tbody>
3642             </entrytbl>
3643           </row>
3644           <row><entry></entry></row>
3645
3646           <row>
3647             <entry spanname="id"><constant>V4L2_CID_3A_LOCK</constant></entry>
3648             <entry>bitmask</entry>
3649           </row>
3650           <row>
3651             <entry spanname="descr">This control locks or unlocks the automatic
3652 focus, exposure and white balance. The automatic adjustments can be paused
3653 independently by setting the corresponding lock bit to 1. The camera then retains
3654 the settings until the lock bit is cleared. The following lock bits are defined:
3655 </entry>
3656           </row>
3657           <row>
3658             <entrytbl spanname="descr" cols="2">
3659               <tbody valign="top">
3660                 <row>
3661                   <entry><constant>V4L2_LOCK_EXPOSURE</constant></entry>
3662                   <entry>Automatic exposure adjustments lock.</entry>
3663                 </row>
3664                 <row>
3665                   <entry><constant>V4L2_LOCK_WHITE_BALANCE</constant></entry>
3666                   <entry>Automatic white balance adjustments lock.</entry>
3667                 </row>
3668                 <row>
3669                   <entry><constant>V4L2_LOCK_FOCUS</constant></entry>
3670                   <entry>Automatic focus lock.</entry>
3671                 </row>
3672               </tbody>
3673             </entrytbl>
3674           </row>
3675           <row><entry spanname="descr">
3676 When a given algorithm is not enabled, drivers should ignore requests
3677 to lock it and should return no error. An example might be an application
3678 setting bit <constant>V4L2_LOCK_WHITE_BALANCE</constant> when the
3679 <constant>V4L2_CID_AUTO_WHITE_BALANCE</constant> control is set to
3680 <constant>FALSE</constant>. The value of this control may be changed
3681 by exposure, white balance or focus controls.</entry>
3682           </row>
3683           <row><entry></entry></row>
3684
3685         </tbody>
3686       </tgroup>
3687     </table>
3688   </section>
3689
3690     <section id="fm-tx-controls">
3691       <title>FM Transmitter Control Reference</title>
3692
3693       <para>The FM Transmitter (FM_TX) class includes controls for common features of
3694 FM transmissions capable devices. Currently this class includes parameters for audio
3695 compression, pilot tone generation, audio deviation limiter, RDS transmission and
3696 tuning power features.</para>
3697
3698       <table pgwide="1" frame="none" id="fm-tx-control-id">
3699       <title>FM_TX Control IDs</title>
3700
3701       <tgroup cols="4">
3702         <colspec colname="c1" colwidth="1*" />
3703         <colspec colname="c2" colwidth="6*" />
3704         <colspec colname="c3" colwidth="2*" />
3705         <colspec colname="c4" colwidth="6*" />
3706         <spanspec namest="c1" nameend="c2" spanname="id" />
3707         <spanspec namest="c2" nameend="c4" spanname="descr" />
3708         <thead>
3709           <row>
3710             <entry spanname="id" align="left">ID</entry>
3711             <entry align="left">Type</entry>
3712           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
3713           </row>
3714         </thead>
3715         <tbody valign="top">
3716           <row><entry></entry></row>
3717           <row>
3718             <entry spanname="id"><constant>V4L2_CID_FM_TX_CLASS</constant>&nbsp;</entry>
3719             <entry>class</entry>
3720           </row><row><entry spanname="descr">The FM_TX class
3721 descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
3722 description of this control class.</entry>
3723           </row>
3724           <row>
3725             <entry spanname="id"><constant>V4L2_CID_RDS_TX_DEVIATION</constant>&nbsp;</entry>
3726             <entry>integer</entry>
3727           </row>
3728           <row><entry spanname="descr">Configures RDS signal frequency deviation level in Hz.
3729 The range and step are driver-specific.</entry>
3730           </row>
3731           <row>
3732             <entry spanname="id"><constant>V4L2_CID_RDS_TX_PI</constant>&nbsp;</entry>
3733             <entry>integer</entry>
3734           </row>
3735           <row><entry spanname="descr">Sets the RDS Programme Identification field
3736 for transmission.</entry>
3737           </row>
3738           <row>
3739             <entry spanname="id"><constant>V4L2_CID_RDS_TX_PTY</constant>&nbsp;</entry>
3740             <entry>integer</entry>
3741           </row>
3742           <row><entry spanname="descr">Sets the RDS Programme Type field for transmission.
3743 This encodes up to 31 pre-defined programme types.</entry>
3744           </row>
3745           <row>
3746             <entry spanname="id"><constant>V4L2_CID_RDS_TX_PS_NAME</constant>&nbsp;</entry>
3747             <entry>string</entry>
3748           </row>
3749           <row><entry spanname="descr">Sets the Programme Service name (PS_NAME) for transmission.
3750 It is intended for static display on a receiver. It is the primary aid to listeners in programme service
3751 identification and selection.  In Annex E of <xref linkend="iec62106" />, the RDS specification,
3752 there is a full description of the correct character encoding for Programme Service name strings.
3753 Also from RDS specification, PS is usually a single eight character text. However, it is also possible
3754 to find receivers which can scroll strings sized as 8 x N characters. So, this control must be configured
3755 with steps of 8 characters. The result is it must always contain a string with size multiple of 8.</entry>
3756           </row>
3757           <row>
3758             <entry spanname="id"><constant>V4L2_CID_RDS_TX_RADIO_TEXT</constant>&nbsp;</entry>
3759             <entry>string</entry>
3760           </row>
3761           <row><entry spanname="descr">Sets the Radio Text info for transmission. It is a textual description of
3762 what is being broadcasted. RDS Radio Text can be applied when broadcaster wishes to transmit longer PS names,
3763 programme-related information or any other text. In these cases, RadioText should be used in addition to
3764 <constant>V4L2_CID_RDS_TX_PS_NAME</constant>. The encoding for Radio Text strings is also fully described
3765 in Annex E of <xref linkend="iec62106" />. The length of Radio Text strings depends on which RDS Block is being
3766 used to transmit it, either 32 (2A block) or 64 (2B block).  However, it is also possible
3767 to find receivers which can scroll strings sized as 32 x N or 64 x N characters. So, this control must be configured
3768 with steps of 32 or 64 characters. The result is it must always contain a string with size multiple of 32 or 64. </entry>
3769           </row>
3770           <row>
3771             <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_ENABLED</constant>&nbsp;</entry>
3772             <entry>boolean</entry>
3773           </row>
3774           <row><entry spanname="descr">Enables or disables the audio deviation limiter feature.
3775 The limiter is useful when trying to maximize the audio volume, minimize receiver-generated
3776 distortion and prevent overmodulation.
3777 </entry>
3778           </row>
3779           <row>
3780             <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_RELEASE_TIME</constant>&nbsp;</entry>
3781             <entry>integer</entry>
3782           </row>
3783           <row><entry spanname="descr">Sets the audio deviation limiter feature release time.
3784 Unit is in useconds. Step and range are driver-specific.</entry>
3785           </row>
3786           <row>
3787             <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_DEVIATION</constant>&nbsp;</entry>
3788             <entry>integer</entry>
3789           </row>
3790           <row><entry spanname="descr">Configures audio frequency deviation level in Hz.
3791 The range and step are driver-specific.</entry>
3792           </row>
3793           <row>
3794             <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_ENABLED</constant>&nbsp;</entry>
3795             <entry>boolean</entry>
3796           </row>
3797           <row><entry spanname="descr">Enables or disables the audio compression feature.
3798 This feature amplifies signals below the threshold by a fixed gain and compresses audio
3799 signals above the threshold by the ratio of Threshold/(Gain + Threshold).</entry>
3800           </row>
3801           <row>
3802             <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_GAIN</constant>&nbsp;</entry>
3803             <entry>integer</entry>
3804           </row>
3805           <row><entry spanname="descr">Sets the gain for audio compression feature. It is
3806 a dB value. The range and step are driver-specific.</entry>
3807           </row>
3808           <row>
3809             <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_THRESHOLD</constant>&nbsp;</entry>
3810             <entry>integer</entry>
3811           </row>
3812           <row><entry spanname="descr">Sets the threshold level for audio compression freature.
3813 It is a dB value. The range and step are driver-specific.</entry>
3814           </row>
3815           <row>
3816             <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_ATTACK_TIME</constant>&nbsp;</entry>
3817             <entry>integer</entry>
3818           </row>
3819           <row><entry spanname="descr">Sets the attack time for audio compression feature.
3820 It is a useconds value. The range and step are driver-specific.</entry>
3821           </row>
3822           <row>
3823             <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_RELEASE_TIME</constant>&nbsp;</entry>
3824             <entry>integer</entry>
3825           </row>
3826           <row><entry spanname="descr">Sets the release time for audio compression feature.
3827 It is a useconds value. The range and step are driver-specific.</entry>
3828           </row>
3829           <row>
3830             <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_ENABLED</constant>&nbsp;</entry>
3831             <entry>boolean</entry>
3832           </row>
3833           <row><entry spanname="descr">Enables or disables the pilot tone generation feature.</entry>
3834           </row>
3835           <row>
3836             <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_DEVIATION</constant>&nbsp;</entry>
3837             <entry>integer</entry>
3838           </row>
3839           <row><entry spanname="descr">Configures pilot tone frequency deviation level. Unit is
3840 in Hz. The range and step are driver-specific.</entry>
3841           </row>
3842           <row>
3843             <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_FREQUENCY</constant>&nbsp;</entry>
3844             <entry>integer</entry>
3845           </row>
3846           <row><entry spanname="descr">Configures pilot tone frequency value. Unit is
3847 in Hz. The range and step are driver-specific.</entry>
3848           </row>
3849           <row>
3850             <entry spanname="id"><constant>V4L2_CID_TUNE_PREEMPHASIS</constant>&nbsp;</entry>
3851             <entry>integer</entry>
3852           </row>
3853           <row id="v4l2-preemphasis"><entry spanname="descr">Configures the pre-emphasis value for broadcasting.
3854 A pre-emphasis filter is applied to the broadcast to accentuate the high audio frequencies.
3855 Depending on the region, a time constant of either 50 or 75 useconds is used. The enum&nbsp;v4l2_preemphasis
3856 defines possible values for pre-emphasis. Here they are:</entry>
3857         </row><row>
3858         <entrytbl spanname="descr" cols="2">
3859                   <tbody valign="top">
3860                     <row>
3861                       <entry><constant>V4L2_PREEMPHASIS_DISABLED</constant>&nbsp;</entry>
3862                       <entry>No pre-emphasis is applied.</entry>
3863                     </row>
3864                     <row>
3865                       <entry><constant>V4L2_PREEMPHASIS_50_uS</constant>&nbsp;</entry>
3866                       <entry>A pre-emphasis of 50 uS is used.</entry>
3867                     </row>
3868                     <row>
3869                       <entry><constant>V4L2_PREEMPHASIS_75_uS</constant>&nbsp;</entry>
3870                       <entry>A pre-emphasis of 75 uS is used.</entry>
3871                     </row>
3872                   </tbody>
3873                 </entrytbl>
3874
3875           </row>
3876           <row>
3877             <entry spanname="id"><constant>V4L2_CID_TUNE_POWER_LEVEL</constant>&nbsp;</entry>
3878             <entry>integer</entry>
3879           </row>
3880           <row><entry spanname="descr">Sets the output power level for signal transmission.
3881 Unit is in dBuV. Range and step are driver-specific.</entry>
3882           </row>
3883           <row>
3884             <entry spanname="id"><constant>V4L2_CID_TUNE_ANTENNA_CAPACITOR</constant>&nbsp;</entry>
3885             <entry>integer</entry>
3886           </row>
3887           <row><entry spanname="descr">This selects the value of antenna tuning capacitor
3888 manually or automatically if set to zero. Unit, range and step are driver-specific.</entry>
3889           </row>
3890           <row><entry></entry></row>
3891         </tbody>
3892       </tgroup>
3893       </table>
3894
3895 <para>For more details about RDS specification, refer to
3896 <xref linkend="iec62106" /> document, from CENELEC.</para>
3897     </section>
3898
3899     <section id="flash-controls">
3900       <title>Flash Control Reference</title>
3901
3902       <note>
3903         <title>Experimental</title>
3904
3905         <para>This is an <link linkend="experimental">experimental</link>
3906 interface and may change in the future.</para>
3907       </note>
3908
3909       <para>
3910         The V4L2 flash controls are intended to provide generic access
3911         to flash controller devices. Flash controller devices are
3912         typically used in digital cameras.
3913       </para>
3914
3915       <para>
3916         The interface can support both LED and xenon flash devices. As
3917         of writing this, there is no xenon flash driver using this
3918         interface.
3919       </para>
3920
3921       <section id="flash-controls-use-cases">
3922         <title>Supported use cases</title>
3923
3924         <section>
3925           <title>Unsynchronised LED flash (software strobe)</title>
3926
3927           <para>
3928             Unsynchronised LED flash is controlled directly by the
3929             host as the sensor. The flash must be enabled by the host
3930             before the exposure of the image starts and disabled once
3931             it ends. The host is fully responsible for the timing of
3932             the flash.
3933           </para>
3934
3935           <para>Example of such device: Nokia N900.</para>
3936         </section>
3937
3938         <section>
3939           <title>Synchronised LED flash (hardware strobe)</title>
3940
3941           <para>
3942             The synchronised LED flash is pre-programmed by the host
3943             (power and timeout) but controlled by the sensor through a
3944             strobe signal from the sensor to the flash.
3945           </para>
3946
3947           <para>
3948             The sensor controls the flash duration and timing. This
3949             information typically must be made available to the
3950             sensor.
3951           </para>
3952
3953         </section>
3954
3955         <section>
3956           <title>LED flash as torch</title>
3957
3958           <para>
3959             LED flash may be used as torch in conjunction with another
3960             use case involving camera or individually.
3961           </para>
3962
3963
3964           <table pgwide="1" frame="none" id="flash-control-id">
3965           <title>Flash Control IDs</title>
3966
3967           <tgroup cols="4">
3968         <colspec colname="c1" colwidth="1*" />
3969         <colspec colname="c2" colwidth="6*" />
3970         <colspec colname="c3" colwidth="2*" />
3971         <colspec colname="c4" colwidth="6*" />
3972         <spanspec namest="c1" nameend="c2" spanname="id" />
3973         <spanspec namest="c2" nameend="c4" spanname="descr" />
3974         <thead>
3975           <row>
3976             <entry spanname="id" align="left">ID</entry>
3977             <entry align="left">Type</entry>
3978           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
3979           </row>
3980         </thead>
3981         <tbody valign="top">
3982           <row><entry></entry></row>
3983           <row>
3984             <entry spanname="id"><constant>V4L2_CID_FLASH_CLASS</constant></entry>
3985             <entry>class</entry>
3986           </row>
3987           <row>
3988             <entry spanname="descr">The FLASH class descriptor.</entry>
3989           </row>
3990           <row>
3991             <entry spanname="id"><constant>V4L2_CID_FLASH_LED_MODE</constant></entry>
3992             <entry>menu</entry>
3993           </row>
3994           <row id="v4l2-flash-led-mode">
3995             <entry spanname="descr">Defines the mode of the flash LED,
3996             the high-power white LED attached to the flash controller.
3997             Setting this control may not be possible in presence of
3998             some faults. See V4L2_CID_FLASH_FAULT.</entry>
3999           </row>
4000           <row>
4001             <entrytbl spanname="descr" cols="2">
4002               <tbody valign="top">
4003                 <row>
4004                   <entry><constant>V4L2_FLASH_LED_MODE_NONE</constant></entry>
4005                   <entry>Off.</entry>
4006                 </row>
4007                 <row>
4008                   <entry><constant>V4L2_FLASH_LED_MODE_FLASH</constant></entry>
4009                   <entry>Flash mode.</entry>
4010                 </row>
4011                 <row>
4012                   <entry><constant>V4L2_FLASH_LED_MODE_TORCH</constant></entry>
4013                   <entry>Torch mode. See V4L2_CID_FLASH_TORCH_INTENSITY.</entry>
4014                 </row>
4015               </tbody>
4016             </entrytbl>
4017           </row>
4018           <row>
4019             <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE_SOURCE</constant></entry>
4020             <entry>menu</entry>
4021           </row>
4022           <row id="v4l2-flash-strobe-source"><entry
4023           spanname="descr">Defines the source of the flash LED
4024           strobe.</entry>
4025           </row>
4026           <row>
4027             <entrytbl spanname="descr" cols="2">
4028               <tbody valign="top">
4029                 <row>
4030                   <entry><constant>V4L2_FLASH_STROBE_SOURCE_SOFTWARE</constant></entry>
4031                   <entry>The flash strobe is triggered by using
4032                   the V4L2_CID_FLASH_STROBE control.</entry>
4033                 </row>
4034                 <row>
4035                   <entry><constant>V4L2_FLASH_STROBE_SOURCE_EXTERNAL</constant></entry>
4036                   <entry>The flash strobe is triggered by an
4037                   external source. Typically this is a sensor,
4038                   which makes it possible to synchronises the
4039                   flash strobe start to exposure start.</entry>
4040                 </row>
4041               </tbody>
4042             </entrytbl>
4043           </row>
4044           <row>
4045             <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE</constant></entry>
4046             <entry>button</entry>
4047           </row>
4048           <row>
4049             <entry spanname="descr">Strobe flash. Valid when
4050             V4L2_CID_FLASH_LED_MODE is set to
4051             V4L2_FLASH_LED_MODE_FLASH and V4L2_CID_FLASH_STROBE_SOURCE
4052             is set to V4L2_FLASH_STROBE_SOURCE_SOFTWARE. Setting this
4053             control may not be possible in presence of some faults.
4054             See V4L2_CID_FLASH_FAULT.</entry>
4055           </row>
4056           <row>
4057             <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE_STOP</constant></entry>
4058             <entry>button</entry>
4059           </row>
4060           <row><entry spanname="descr">Stop flash strobe immediately.</entry>
4061           </row>
4062           <row>
4063             <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE_STATUS</constant></entry>
4064             <entry>boolean</entry>
4065           </row>
4066           <row>
4067             <entry spanname="descr">Strobe status: whether the flash
4068             is strobing at the moment or not. This is a read-only
4069             control.</entry>
4070           </row>
4071           <row>
4072             <entry spanname="id"><constant>V4L2_CID_FLASH_TIMEOUT</constant></entry>
4073             <entry>integer</entry>
4074           </row>
4075           <row>
4076             <entry spanname="descr">Hardware timeout for flash. The
4077             flash strobe is stopped after this period of time has
4078             passed from the start of the strobe.</entry>
4079           </row>
4080           <row>
4081             <entry spanname="id"><constant>V4L2_CID_FLASH_INTENSITY</constant></entry>
4082             <entry>integer</entry>
4083           </row>
4084           <row>
4085             <entry spanname="descr">Intensity of the flash strobe when
4086             the flash LED is in flash mode
4087             (V4L2_FLASH_LED_MODE_FLASH). The unit should be milliamps
4088             (mA) if possible.</entry>
4089           </row>
4090           <row>
4091             <entry spanname="id"><constant>V4L2_CID_FLASH_TORCH_INTENSITY</constant></entry>
4092             <entry>integer</entry>
4093           </row>
4094           <row>
4095             <entry spanname="descr">Intensity of the flash LED in
4096             torch mode (V4L2_FLASH_LED_MODE_TORCH). The unit should be
4097             milliamps (mA) if possible. Setting this control may not
4098             be possible in presence of some faults. See
4099             V4L2_CID_FLASH_FAULT.</entry>
4100           </row>
4101           <row>
4102             <entry spanname="id"><constant>V4L2_CID_FLASH_INDICATOR_INTENSITY</constant></entry>
4103             <entry>integer</entry>
4104           </row>
4105           <row>
4106             <entry spanname="descr">Intensity of the indicator LED.
4107             The indicator LED may be fully independent of the flash
4108             LED. The unit should be microamps (uA) if possible.</entry>
4109           </row>
4110           <row>
4111             <entry spanname="id"><constant>V4L2_CID_FLASH_FAULT</constant></entry>
4112             <entry>bitmask</entry>
4113           </row>
4114           <row>
4115             <entry spanname="descr">Faults related to the flash. The
4116             faults tell about specific problems in the flash chip
4117             itself or the LEDs attached to it. Faults may prevent
4118             further use of some of the flash controls. In particular,
4119             V4L2_CID_FLASH_LED_MODE is set to V4L2_FLASH_LED_MODE_NONE
4120             if the fault affects the flash LED. Exactly which faults
4121             have such an effect is chip dependent. Reading the faults
4122             resets the control and returns the chip to a usable state
4123             if possible.</entry>
4124           </row>
4125           <row>
4126             <entrytbl spanname="descr" cols="2">
4127               <tbody valign="top">
4128                 <row>
4129                   <entry><constant>V4L2_FLASH_FAULT_OVER_VOLTAGE</constant></entry>
4130                   <entry>Flash controller voltage to the flash LED
4131                   has exceeded the limit specific to the flash
4132                   controller.</entry>
4133                 </row>
4134                 <row>
4135                   <entry><constant>V4L2_FLASH_FAULT_TIMEOUT</constant></entry>
4136                   <entry>The flash strobe was still on when
4137                   the timeout set by the user ---
4138                   V4L2_CID_FLASH_TIMEOUT control --- has expired.
4139                   Not all flash controllers may set this in all
4140                   such conditions.</entry>
4141                 </row>
4142                 <row>
4143                   <entry><constant>V4L2_FLASH_FAULT_OVER_TEMPERATURE</constant></entry>
4144                   <entry>The flash controller has overheated.</entry>
4145                 </row>
4146                 <row>
4147                   <entry><constant>V4L2_FLASH_FAULT_SHORT_CIRCUIT</constant></entry>
4148                   <entry>The short circuit protection of the flash
4149                   controller has been triggered.</entry>
4150                 </row>
4151                 <row>
4152                   <entry><constant>V4L2_FLASH_FAULT_OVER_CURRENT</constant></entry>
4153                   <entry>Current in the LED power supply has exceeded the limit
4154                   specific to the flash controller.</entry>
4155                 </row>
4156                 <row>
4157                   <entry><constant>V4L2_FLASH_FAULT_INDICATOR</constant></entry>
4158                   <entry>The flash controller has detected a short or open
4159                   circuit condition on the indicator LED.</entry>
4160                 </row>
4161               </tbody>
4162             </entrytbl>
4163           </row>
4164           <row>
4165             <entry spanname="id"><constant>V4L2_CID_FLASH_CHARGE</constant></entry>
4166             <entry>boolean</entry>
4167           </row>
4168           <row><entry spanname="descr">Enable or disable charging of the xenon
4169           flash capacitor.</entry>
4170           </row>
4171           <row>
4172             <entry spanname="id"><constant>V4L2_CID_FLASH_READY</constant></entry>
4173             <entry>boolean</entry>
4174           </row>
4175           <row>
4176             <entry spanname="descr">Is the flash ready to strobe?
4177             Xenon flashes require their capacitors charged before
4178             strobing. LED flashes often require a cooldown period
4179             after strobe during which another strobe will not be
4180             possible. This is a read-only control.</entry>
4181           </row>
4182           <row><entry></entry></row>
4183         </tbody>
4184           </tgroup>
4185           </table>
4186         </section>
4187       </section>
4188     </section>
4189
4190     <section id="jpeg-controls">
4191       <title>JPEG Control Reference</title>
4192       <para>The JPEG class includes controls for common features of JPEG
4193       encoders and decoders. Currently it includes features for codecs
4194       implementing progressive baseline DCT compression process with
4195       Huffman entrophy coding.</para>
4196       <table pgwide="1" frame="none" id="jpeg-control-id">
4197       <title>JPEG Control IDs</title>
4198
4199       <tgroup cols="4">
4200         <colspec colname="c1" colwidth="1*" />
4201         <colspec colname="c2" colwidth="6*" />
4202         <colspec colname="c3" colwidth="2*" />
4203         <colspec colname="c4" colwidth="6*" />
4204         <spanspec namest="c1" nameend="c2" spanname="id" />
4205         <spanspec namest="c2" nameend="c4" spanname="descr" />
4206         <thead>
4207           <row>
4208             <entry spanname="id" align="left">ID</entry>
4209             <entry align="left">Type</entry>
4210           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4211           </row>
4212         </thead>
4213         <tbody valign="top">
4214           <row><entry></entry></row>
4215           <row>
4216             <entry spanname="id"><constant>V4L2_CID_JPEG_CLASS</constant>&nbsp;</entry>
4217             <entry>class</entry>
4218           </row><row><entry spanname="descr">The JPEG class descriptor. Calling
4219           &VIDIOC-QUERYCTRL; for this control will return a description of this
4220           control class.
4221
4222         </entry>
4223           </row>
4224           <row>
4225             <entry spanname="id"><constant>V4L2_CID_JPEG_CHROMA_SUBSAMPLING</constant></entry>
4226             <entry>menu</entry>
4227           </row>
4228           <row id="v4l2-jpeg-chroma-subsampling">
4229             <entry spanname="descr">The chroma subsampling factors describe how
4230             each component of an input image is sampled, in respect to maximum
4231             sample rate in each spatial dimension. See <xref linkend="itu-t81"/>,
4232             clause A.1.1. for more details. The <constant>
4233             V4L2_CID_JPEG_CHROMA_SUBSAMPLING</constant> control determines how
4234             Cb and Cr components are downsampled after coverting an input image
4235             from RGB to Y'CbCr color space.
4236             </entry>
4237           </row>
4238           <row>
4239             <entrytbl spanname="descr" cols="2">
4240               <tbody valign="top">
4241                 <row>
4242                   <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_444</constant>
4243                   </entry><entry>No chroma subsampling, each pixel has
4244                   Y, Cr and Cb values.</entry>
4245                 </row>
4246                 <row>
4247                   <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_422</constant>
4248                   </entry><entry>Horizontally subsample Cr, Cb components
4249                   by a factor of 2.</entry>
4250                 </row>
4251                 <row>
4252                   <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_420</constant>
4253                   </entry><entry>Subsample Cr, Cb components horizontally
4254                   and vertically by 2.</entry>
4255                 </row>
4256                 <row>
4257                   <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_411</constant>
4258                   </entry><entry>Horizontally subsample Cr, Cb components
4259                   by a factor of 4.</entry>
4260                 </row>
4261                 <row>
4262                   <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_410</constant>
4263                   </entry><entry>Subsample Cr, Cb components horizontally
4264                   by 4 and vertically by 2.</entry>
4265                 </row>
4266                 <row>
4267                   <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_GRAY</constant>
4268                   </entry><entry>Use only luminance component.</entry>
4269                 </row>
4270               </tbody>
4271             </entrytbl>
4272           </row>
4273           <row>
4274             <entry spanname="id"><constant>V4L2_CID_JPEG_RESTART_INTERVAL</constant>
4275             </entry><entry>integer</entry>
4276           </row>
4277           <row><entry spanname="descr">
4278               The restart interval determines an interval of inserting RSTm
4279               markers (m = 0..7). The purpose of these markers is to additionally
4280               reinitialize the encoder process, in order to process blocks of
4281               an image independently.
4282               For the lossy compression processes the restart interval unit is
4283               MCU (Minimum Coded Unit) and its value is contained in DRI
4284               (Define Restart Interval) marker. If <constant>
4285               V4L2_CID_JPEG_RESTART_INTERVAL</constant> control is set to 0,
4286               DRI and RSTm markers will not be inserted.
4287             </entry>
4288           </row>
4289           <row id="jpeg-quality-control">
4290             <entry spanname="id"><constant>V4L2_CID_JPEG_COMPRESSION_QUALITY</constant></entry>
4291             <entry>integer</entry>
4292           </row>
4293           <row>
4294             <entry spanname="descr">
4295               <constant>V4L2_CID_JPEG_COMPRESSION_QUALITY</constant> control
4296               determines trade-off between image quality and size.
4297               It provides simpler method for applications to control image quality,
4298               without a need for direct reconfiguration of luminance and chrominance
4299               quantization tables.
4300
4301               In cases where a driver uses quantization tables configured directly
4302               by an application, using interfaces defined elsewhere, <constant>
4303               V4L2_CID_JPEG_COMPRESSION_QUALITY</constant> control should be set
4304               by driver to 0.
4305
4306               <para>The value range of this control is driver-specific. Only
4307               positive, non-zero values are meaningful. The recommended range
4308               is 1 - 100, where larger values correspond to better image quality.
4309               </para>
4310             </entry>
4311             </row>
4312           <row id="jpeg-active-marker-control">
4313             <entry spanname="id"><constant>V4L2_CID_JPEG_ACTIVE_MARKER</constant></entry>
4314             <entry>bitmask</entry>
4315           </row>
4316           <row>
4317             <entry spanname="descr">Specify which JPEG markers are included
4318             in compressed stream. This control is valid only for encoders.
4319             </entry>
4320           </row>
4321           <row>
4322             <entrytbl spanname="descr" cols="2">
4323               <tbody valign="top">
4324                 <row>
4325                   <entry><constant>V4L2_JPEG_ACTIVE_MARKER_APP0</constant></entry>
4326                   <entry>Application data segment APP<subscript>0</subscript>.</entry>
4327                 </row><row>
4328                   <entry><constant>V4L2_JPEG_ACTIVE_MARKER_APP1</constant></entry>
4329                   <entry>Application data segment APP<subscript>1</subscript>.</entry>
4330                 </row><row>
4331                   <entry><constant>V4L2_JPEG_ACTIVE_MARKER_COM</constant></entry>
4332                   <entry>Comment segment.</entry>
4333                 </row><row>
4334                   <entry><constant>V4L2_JPEG_ACTIVE_MARKER_DQT</constant></entry>
4335                   <entry>Quantization tables segment.</entry>
4336                 </row><row>
4337                   <entry><constant>V4L2_JPEG_ACTIVE_MARKER_DHT</constant></entry>
4338                   <entry>Huffman tables segment.</entry>
4339                 </row>
4340               </tbody>
4341             </entrytbl>
4342           </row>
4343           <row><entry></entry></row>
4344         </tbody>
4345       </tgroup>
4346       </table>
4347       <para>For more details about JPEG specification, refer
4348       to <xref linkend="itu-t81"/>, <xref linkend="jfif"/>,
4349       <xref linkend="w3c-jpeg-jfif"/>.</para>
4350     </section>
4351
4352     <section id="image-source-controls">
4353       <title>Image Source Control Reference</title>
4354
4355       <note>
4356         <title>Experimental</title>
4357
4358         <para>This is an <link
4359         linkend="experimental">experimental</link> interface and may
4360         change in the future.</para>
4361       </note>
4362
4363       <para>
4364         The Image Source control class is intended for low-level
4365         control of image source devices such as image sensors. The
4366         devices feature an analogue to digital converter and a bus
4367         transmitter to transmit the image data out of the device.
4368       </para>
4369
4370       <table pgwide="1" frame="none" id="image-source-control-id">
4371       <title>Image Source Control IDs</title>
4372
4373       <tgroup cols="4">
4374         <colspec colname="c1" colwidth="1*" />
4375         <colspec colname="c2" colwidth="6*" />
4376         <colspec colname="c3" colwidth="2*" />
4377         <colspec colname="c4" colwidth="6*" />
4378         <spanspec namest="c1" nameend="c2" spanname="id" />
4379         <spanspec namest="c2" nameend="c4" spanname="descr" />
4380         <thead>
4381           <row>
4382             <entry spanname="id" align="left">ID</entry>
4383             <entry align="left">Type</entry>
4384           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4385           </row>
4386         </thead>
4387         <tbody valign="top">
4388           <row><entry></entry></row>
4389           <row>
4390             <entry spanname="id"><constant>V4L2_CID_IMAGE_SOURCE_CLASS</constant></entry>
4391             <entry>class</entry>
4392           </row>
4393           <row>
4394             <entry spanname="descr">The IMAGE_SOURCE class descriptor.</entry>
4395           </row>
4396           <row>
4397             <entry spanname="id"><constant>V4L2_CID_VBLANK</constant></entry>
4398             <entry>integer</entry>
4399           </row>
4400           <row>
4401             <entry spanname="descr">Vertical blanking. The idle period
4402             after every frame during which no image data is produced.
4403             The unit of vertical blanking is a line. Every line has
4404             length of the image width plus horizontal blanking at the
4405             pixel rate defined by
4406             <constant>V4L2_CID_PIXEL_RATE</constant> control in the
4407             same sub-device.</entry>
4408           </row>
4409           <row>
4410             <entry spanname="id"><constant>V4L2_CID_HBLANK</constant></entry>
4411             <entry>integer</entry>
4412           </row>
4413           <row>
4414             <entry spanname="descr">Horizontal blanking. The idle
4415             period after every line of image data during which no
4416             image data is produced. The unit of horizontal blanking is
4417             pixels.</entry>
4418           </row>
4419           <row>
4420             <entry spanname="id"><constant>V4L2_CID_ANALOGUE_GAIN</constant></entry>
4421             <entry>integer</entry>
4422           </row>
4423           <row>
4424             <entry spanname="descr">Analogue gain is gain affecting
4425             all colour components in the pixel matrix. The gain
4426             operation is performed in the analogue domain before A/D
4427             conversion.
4428             </entry>
4429           </row>
4430           <row><entry></entry></row>
4431         </tbody>
4432       </tgroup>
4433       </table>
4434
4435     </section>
4436
4437     <section id="image-process-controls">
4438       <title>Image Process Control Reference</title>
4439
4440       <note>
4441         <title>Experimental</title>
4442
4443         <para>This is an <link
4444         linkend="experimental">experimental</link> interface and may
4445         change in the future.</para>
4446       </note>
4447
4448       <para>
4449         The Image Source control class is intended for low-level control of
4450         image processing functions. Unlike
4451         <constant>V4L2_CID_IMAGE_SOURCE_CLASS</constant>, the controls in
4452         this class affect processing the image, and do not control capturing
4453         of it.
4454       </para>
4455
4456       <table pgwide="1" frame="none" id="image-process-control-id">
4457       <title>Image Source Control IDs</title>
4458
4459       <tgroup cols="4">
4460         <colspec colname="c1" colwidth="1*" />
4461         <colspec colname="c2" colwidth="6*" />
4462         <colspec colname="c3" colwidth="2*" />
4463         <colspec colname="c4" colwidth="6*" />
4464         <spanspec namest="c1" nameend="c2" spanname="id" />
4465         <spanspec namest="c2" nameend="c4" spanname="descr" />
4466         <thead>
4467           <row>
4468             <entry spanname="id" align="left">ID</entry>
4469             <entry align="left">Type</entry>
4470           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4471           </row>
4472         </thead>
4473         <tbody valign="top">
4474           <row><entry></entry></row>
4475           <row>
4476             <entry spanname="id"><constant>V4L2_CID_IMAGE_PROC_CLASS</constant></entry>
4477             <entry>class</entry>
4478           </row>
4479           <row>
4480             <entry spanname="descr">The IMAGE_PROC class descriptor.</entry>
4481           </row>
4482           <row>
4483             <entry spanname="id"><constant>V4L2_CID_LINK_FREQ</constant></entry>
4484             <entry>integer menu</entry>
4485           </row>
4486           <row>
4487             <entry spanname="descr">Data bus frequency. Together with the
4488             media bus pixel code, bus type (clock cycles per sample), the
4489             data bus frequency defines the pixel rate
4490             (<constant>V4L2_CID_PIXEL_RATE</constant>) in the
4491             pixel array (or possibly elsewhere, if the device is not an
4492             image sensor). The frame rate can be calculated from the pixel
4493             clock, image width and height and horizontal and vertical
4494             blanking. While the pixel rate control may be defined elsewhere
4495             than in the subdev containing the pixel array, the frame rate
4496             cannot be obtained from that information. This is because only
4497             on the pixel array it can be assumed that the vertical and
4498             horizontal blanking information is exact: no other blanking is
4499             allowed in the pixel array. The selection of frame rate is
4500             performed by selecting the desired horizontal and vertical
4501             blanking. The unit of this control is Hz. </entry>
4502           </row>
4503           <row>
4504             <entry spanname="id"><constant>V4L2_CID_PIXEL_RATE</constant></entry>
4505             <entry>64-bit integer</entry>
4506           </row>
4507           <row>
4508             <entry spanname="descr">Pixel rate in the source pads of
4509             the subdev. This control is read-only and its unit is
4510             pixels / second.
4511             </entry>
4512           </row>
4513           <row>
4514             <entry spanname="id"><constant>V4L2_CID_TEST_PATTERN</constant></entry>
4515             <entry>menu</entry>
4516           </row>
4517           <row id="v4l2-test-pattern">
4518             <entry spanname="descr"> Some capture/display/sensor devices have
4519             the capability to generate test pattern images. These hardware
4520             specific test patterns can be used to test if a device is working
4521             properly.</entry>
4522           </row>
4523           <row><entry></entry></row>
4524         </tbody>
4525       </tgroup>
4526       </table>
4527
4528     </section>
4529
4530     <section id="dv-controls">
4531       <title>Digital Video Control Reference</title>
4532
4533       <note>
4534         <title>Experimental</title>
4535
4536         <para>This is an <link
4537         linkend="experimental">experimental</link> interface and may
4538         change in the future.</para>
4539       </note>
4540
4541       <para>
4542         The Digital Video control class is intended to control receivers
4543         and transmitters for <ulink url="http://en.wikipedia.org/wiki/Vga">VGA</ulink>,
4544         <ulink url="http://en.wikipedia.org/wiki/Digital_Visual_Interface">DVI</ulink>
4545         (Digital Visual Interface), HDMI (<xref linkend="hdmi" />) and DisplayPort (<xref linkend="dp" />).
4546         These controls are generally expected to be private to the receiver or transmitter
4547         subdevice that implements them, so they are only exposed on the
4548         <filename>/dev/v4l-subdev*</filename> device node.
4549       </para>
4550
4551       <para>Note that these devices can have multiple input or output pads which are
4552       hooked up to e.g. HDMI connectors. Even though the subdevice will receive or
4553       transmit video from/to only one of those pads, the other pads can still be
4554       active when it comes to EDID (Extended Display Identification Data,
4555       <xref linkend="vesaedid" />) and HDCP (High-bandwidth Digital Content
4556       Protection System, <xref linkend="hdcp" />) processing, allowing the device
4557       to do the fairly slow EDID/HDCP handling in advance. This allows for quick
4558       switching between connectors.</para>
4559
4560       <para>These pads appear in several of the controls in this section as
4561       bitmasks, one bit for each pad. Bit 0 corresponds to pad 0, bit 1 to pad 1,
4562       etc. The maximum value of the control is the set of valid pads.</para>
4563
4564       <table pgwide="1" frame="none" id="dv-control-id">
4565       <title>Digital Video Control IDs</title>
4566
4567       <tgroup cols="4">
4568         <colspec colname="c1" colwidth="1*" />
4569         <colspec colname="c2" colwidth="6*" />
4570         <colspec colname="c3" colwidth="2*" />
4571         <colspec colname="c4" colwidth="6*" />
4572         <spanspec namest="c1" nameend="c2" spanname="id" />
4573         <spanspec namest="c2" nameend="c4" spanname="descr" />
4574         <thead>
4575           <row>
4576             <entry spanname="id" align="left">ID</entry>
4577             <entry align="left">Type</entry>
4578           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4579           </row>
4580         </thead>
4581         <tbody valign="top">
4582           <row><entry></entry></row>
4583           <row>
4584             <entry spanname="id"><constant>V4L2_CID_DV_CLASS</constant></entry>
4585             <entry>class</entry>
4586           </row>
4587           <row>
4588             <entry spanname="descr">The Digital Video class descriptor.</entry>
4589           </row>
4590           <row>
4591             <entry spanname="id"><constant>V4L2_CID_DV_TX_HOTPLUG</constant></entry>
4592             <entry>bitmask</entry>
4593           </row>
4594           <row>
4595             <entry spanname="descr">Many connectors have a hotplug pin which is high
4596             if EDID information is available from the source. This control shows the
4597             state of the hotplug pin as seen by the transmitter.
4598             Each bit corresponds to an output pad on the transmitter. If an output pad
4599             does not have an associated hotplug pin, then the bit for that pad will be 0.
4600             This read-only control is applicable to DVI-D, HDMI and DisplayPort connectors.
4601             </entry>
4602           </row>
4603           <row>
4604             <entry spanname="id"><constant>V4L2_CID_DV_TX_RXSENSE</constant></entry>
4605             <entry>bitmask</entry>
4606           </row>
4607           <row>
4608             <entry spanname="descr">Rx Sense is the detection of pull-ups on the TMDS
4609             clock lines. This normally means that the sink has left/entered standby (i.e.
4610             the transmitter can sense that the receiver is ready to receive video).
4611             Each bit corresponds to an output pad on the transmitter. If an output pad
4612             does not have an associated Rx Sense, then the bit for that pad will be 0.
4613             This read-only control is applicable to DVI-D and HDMI devices.
4614             </entry>
4615           </row>
4616           <row>
4617             <entry spanname="id"><constant>V4L2_CID_DV_TX_EDID_PRESENT</constant></entry>
4618             <entry>bitmask</entry>
4619           </row>
4620           <row>
4621             <entry spanname="descr">When the transmitter sees the hotplug signal from the
4622             receiver it will attempt to read the EDID. If set, then the transmitter has read
4623             at least the first block (= 128 bytes).
4624             Each bit corresponds to an output pad on the transmitter. If an output pad
4625             does not support EDIDs, then the bit for that pad will be 0.
4626             This read-only control is applicable to VGA, DVI-A/D, HDMI and DisplayPort connectors.
4627             </entry>
4628           </row>
4629           <row>
4630             <entry spanname="id"><constant>V4L2_CID_DV_TX_MODE</constant></entry>
4631             <entry id="v4l2-dv-tx-mode">enum v4l2_dv_tx_mode</entry>
4632           </row>
4633           <row>
4634             <entry spanname="descr">HDMI transmitters can transmit in DVI-D mode (just video)
4635             or in HDMI mode (video + audio + auxiliary data). This control selects which mode
4636             to use: V4L2_DV_TX_MODE_DVI_D or V4L2_DV_TX_MODE_HDMI.
4637             This control is applicable to HDMI connectors.
4638             </entry>
4639           </row>
4640           <row>
4641             <entry spanname="id"><constant>V4L2_CID_DV_TX_RGB_RANGE</constant></entry>
4642             <entry id="v4l2-dv-rgb-range">enum v4l2_dv_rgb_range</entry>
4643           </row>
4644           <row>
4645             <entry spanname="descr">Select the quantization range for RGB output. V4L2_DV_RANGE_AUTO
4646             follows the RGB quantization range specified in the standard for the video interface
4647             (ie. <xref linkend="cea861" /> for HDMI). V4L2_DV_RANGE_LIMITED and V4L2_DV_RANGE_FULL override the standard
4648             to be compatible with sinks that have not implemented the standard correctly
4649             (unfortunately quite common for HDMI and DVI-D). Full range allows all possible values to be
4650             used whereas limited range sets the range to (16 &lt;&lt; (N-8)) - (235 &lt;&lt; (N-8))
4651             where N is the number of bits per component.
4652             This control is applicable to VGA, DVI-A/D, HDMI and DisplayPort connectors.
4653             </entry>
4654           </row>
4655           <row>
4656             <entry spanname="id"><constant>V4L2_CID_DV_RX_POWER_PRESENT</constant></entry>
4657             <entry>bitmask</entry>
4658           </row>
4659           <row>
4660             <entry spanname="descr">Detects whether the receiver receives power from the source
4661             (e.g. HDMI carries 5V on one of the pins). This is often used to power an eeprom
4662             which contains EDID information, such that the source can read the EDID even if
4663             the sink is in standby/power off.
4664             Each bit corresponds to an input pad on the transmitter. If an input pad
4665             cannot detect whether power is present, then the bit for that pad will be 0.
4666             This read-only control is applicable to DVI-D, HDMI and DisplayPort connectors.
4667             </entry>
4668           </row>
4669           <row>
4670             <entry spanname="id"><constant>V4L2_CID_DV_RX_RGB_RANGE</constant></entry>
4671             <entry>enum v4l2_dv_rgb_range</entry>
4672           </row>
4673           <row>
4674             <entry spanname="descr">Select the quantization range for RGB input. V4L2_DV_RANGE_AUTO
4675             follows the RGB quantization range specified in the standard for the video interface
4676             (ie. <xref linkend="cea861" /> for HDMI). V4L2_DV_RANGE_LIMITED and V4L2_DV_RANGE_FULL override the standard
4677             to be compatible with sources that have not implemented the standard correctly
4678             (unfortunately quite common for HDMI and DVI-D). Full range allows all possible values to be
4679             used whereas limited range sets the range to (16 &lt;&lt; (N-8)) - (235 &lt;&lt; (N-8))
4680             where N is the number of bits per component.
4681             This control is applicable to VGA, DVI-A/D, HDMI and DisplayPort connectors.
4682             </entry>
4683           </row>
4684           <row><entry></entry></row>
4685         </tbody>
4686       </tgroup>
4687       </table>
4688
4689     </section>
4690 </section>