--- /dev/null
+/*\r
+ * 11/19/04 1.0 moved to LGPL.\r
+ * 01/12/99 Initial version. mdm@techie.com\r
+ *-----------------------------------------------------------------------\r
+ * This program is free software; you can redistribute it and/or modify\r
+ * it under the terms of the GNU Library General Public License as published\r
+ * by the Free Software Foundation; either version 2 of the License, or\r
+ * (at your option) any later version.\r
+ *\r
+ * This program is distributed in the hope that it will be useful,\r
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of\r
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the\r
+ * GNU Library General Public License for more details.\r
+ *\r
+ * You should have received a copy of the GNU Library General Public\r
+ * License along with this program; if not, write to the Free Software\r
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.\r
+ *----------------------------------------------------------------------\r
+ */\r
+\r
+/**\r
+ * The <code>Decoder</code> class encapsulates the details of decoding an MPEG\r
+ * audio frame.\r
+ * \r
+ * @author MDM\r
+ * @version 0.0.7 12/12/99\r
+ * @since 0.0.5\r
+ */\r
+\r
+\r
+public class Decoder implements DecoderErrors {\r
+\r
+ static private final Params DEFAULT_PARAMS = new Params();\r
+\r
+ /**\r
+ * The Bistream from which the MPEG audio frames are read.\r
+ */\r
+ // \r
+ // private Bitstream stream;\r
+\r
+ /**\r
+ * The Obuffer instance that will receive the decoded PCM samples.\r
+ */\r
+ // \r
+ // private Obuffer output;\r
+\r
+ /**\r
+ * Synthesis filter for the left channel.\r
+ */\r
+ // \r
+ // private SynthesisFilter filter1;\r
+\r
+ /**\r
+ * Sythesis filter for the right channel.\r
+ */\r
+ // \r
+ // private SynthesisFilter filter2;\r
+\r
+ /**\r
+ * The decoder used to decode layer III frames.\r
+ */\r
+ \r
+ private LayerIIIDecoder l3decoder;\r
+ // \r
+ // private LayerIIDecoder l2decoder;\r
+ // \r
+ // private LayerIDecoder l1decoder;\r
+\r
+ \r
+ private int outputFrequency;\r
+ \r
+ private int outputChannels;\r
+\r
+ \r
+ private Equalizer equalizer = new Equalizer();\r
+\r
+ \r
+ private Params params;\r
+\r
+ \r
+ private boolean initialized;\r
+\r
+ /**\r
+ * Creates a new <code>Decoder</code> instance with default parameters.\r
+ */\r
+\r
+ public Decoder() {\r
+ this(null);\r
+ }\r
+\r
+ /**\r
+ * Creates a new <code>Decoder</code> instance with default parameters.\r
+ * \r
+ * @param params\r
+ * The <code>Params</code> instance that describes the customizable\r
+ * aspects of the decoder.\r
+ */\r
+ public Decoder(@DELEGATE Params params0) {\r
+\r
+ if (params0 == null) {\r
+ params0 = getDefaultParams();\r
+ }\r
+\r
+ params = params0;\r
+\r
+ Equalizer eq = params.getInitialEqualizerSettings();\r
+ if (eq != null) {\r
+ equalizer.setFrom(eq);\r
+ }\r
+ }\r
+\r
+ static public Params getDefaultParams() {\r
+ return (Params) DEFAULT_PARAMS.clone();\r
+ }\r
+\r
+ // public void setEqualizer(Equalizer eq) {\r
+ // if (eq == null)\r
+ // eq = Equalizer.PASS_THRU_EQ;\r
+ //\r
+ // equalizer.setFrom(eq);\r
+ //\r
+ // float[] factors = equalizer.getBandFactors();\r
+ //\r
+ // if (filter1 != null)\r
+ // filter1.setEQ(factors);\r
+ //\r
+ // if (filter2 != null)\r
+ // filter2.setEQ(factors);\r
+ // }\r
+ \r
+ public void init( Header header) {\r
+ float scalefactor = 32700.0f;\r
+\r
+ int mode = header.mode();\r
+ int layer = header.layer();\r
+ int channels = mode == Header.SINGLE_CHANNEL ? 1 : 2;\r
+\r
+ // set up output buffer if not set up by client.\r
+ // if (output == null)\r
+ // output = new SampleBuffer(header.frequency(), channels);\r
+ SampleBufferWrapper.init(header.frequency(), channels);\r
+\r
+ float[] factors = equalizer.getBandFactors();\r
+ SynthesisFilter filter1 =\r
+ new SynthesisFilter(0, scalefactor, factors);\r
+\r
+ // REVIEW: allow mono output for stereo\r
+ SynthesisFilter filter2 = null;\r
+ if (channels == 2) {\r
+ filter2 = new SynthesisFilter(1, scalefactor, factors);\r
+ }\r
+\r
+ outputChannels = channels;\r
+ outputFrequency = header.frequency();\r
+\r
+ l3decoder = new LayerIIIDecoder(header,filter1, filter2, OutputChannels.BOTH_CHANNELS);\r
+\r
+ }\r
+\r
+ /**\r
+ * Decodes one frame from an MPEG audio bitstream.\r
+ * \r
+ * @param header\r
+ * The header describing the frame to decode.\r
+ * @param bitstream\r
+ * The bistream that provides the bits for te body of the frame.\r
+ * \r
+ * @return A SampleBuffer containing the decoded samples.\r
+ */\r
+ \r
+ public void decodeFrame( Header header) throws DecoderException {\r
+\r
+ SampleBufferWrapper.clear_buffer();\r
+ l3decoder.decode(header);\r
+ // SampleBufferWrapper.getOutput().write_buffer(1);\r
+\r
+ }\r
+\r
+ /**\r
+ * Changes the output buffer. This will take effect the next time\r
+ * decodeFrame() is called.\r
+ */\r
+ // public void setOutputBuffer(Obuffer out) {\r
+ // output = out;\r
+ // }\r
+\r
+ /**\r
+ * Retrieves the sample frequency of the PCM samples output by this decoder.\r
+ * This typically corresponds to the sample rate encoded in the MPEG audio\r
+ * stream.\r
+ * \r
+ * @param the\r
+ * sample rate (in Hz) of the samples written to the output buffer\r
+ * when decoding.\r
+ */\r
+ public int getOutputFrequency() {\r
+ return outputFrequency;\r
+ }\r
+\r
+ /**\r
+ * Retrieves the number of channels of PCM samples output by this decoder.\r
+ * This usually corresponds to the number of channels in the MPEG audio\r
+ * stream, although it may differ.\r
+ * \r
+ * @return The number of output channels in the decoded samples: 1 for mono,\r
+ * or 2 for stereo.\r
+ * \r
+ */\r
+ public int getOutputChannels() {\r
+ return outputChannels;\r
+ }\r
+\r
+ /**\r
+ * Retrieves the maximum number of samples that will be written to the output\r
+ * buffer when one frame is decoded. This can be used to help calculate the\r
+ * size of other buffers whose size is based upon the number of samples\r
+ * written to the output buffer. NB: this is an upper bound and fewer samples\r
+ * may actually be written, depending upon the sample rate and number of\r
+ * channels.\r
+ * \r
+ * @return The maximum number of samples that are written to the output buffer\r
+ * when decoding a single frame of MPEG audio.\r
+ */\r
+ public int getOutputBlockSize() {\r
+ return Obuffer.OBUFFERSIZE;\r
+ }\r
+\r
+ protected DecoderException newDecoderException(int errorcode) {\r
+ return new DecoderException(errorcode, null);\r
+ }\r
+\r
+ protected DecoderException newDecoderException(int errorcode, Throwable throwable) {\r
+ return new DecoderException(errorcode, throwable);\r
+ }\r
+}\r
+\r
+\r
+\r
+\r
+\r
+ /**\r
+ * The <code>Params</code> class presents the customizable aspects of the\r
+ * decoder.\r
+ * <p>\r
+ * Instances of this class are not thread safe.\r
+ */\r
+ public class Params implements Cloneable {\r
+\r
+ // private OutputChannels outputChannels = OutputChannels.BOTH;\r
+ private OutputChannels outputChannels = new OutputChannels(0);\r
+\r
+ private Equalizer equalizer = new Equalizer();\r
+\r
+ public Params() {\r
+ }\r
+\r
+ public Object clone() {\r
+ // TODO: need to have better clone method\r
+ Params clone = new Params();\r
+ clone.outputChannels = new OutputChannels(outputChannels.getChannelsOutputCode());\r
+ clone.equalizer = new Equalizer();\r
+ return clone;\r
+ // try\r
+ // {\r
+ // return super.clone();\r
+ // }\r
+ // catch (CloneNotSupportedException ex)\r
+ // {\r
+ // throw new InternalError(this+": "+ex);\r
+ // }\r
+ }\r
+\r
+ public void setOutputChannels(OutputChannels out) {\r
+ if (out == null)\r
+ throw new NullPointerException("out");\r
+\r
+ outputChannels = out;\r
+ }\r
+\r
+ public OutputChannels getOutputChannels() {\r
+ return outputChannels;\r
+ }\r
+\r
+ /**\r
+ * Retrieves the equalizer settings that the decoder's equalizer will be\r
+ * initialized from.\r
+ * <p>\r
+ * The <code>Equalizer</code> instance returned cannot be changed in real\r
+ * time to affect the decoder output as it is used only to initialize the\r
+ * decoders EQ settings. To affect the decoder's output in realtime, use the\r
+ * Equalizer returned from the getEqualizer() method on the decoder.\r
+ * \r
+ * @return The <code>Equalizer</code> used to initialize the EQ settings of\r
+ * the decoder.\r
+ */\r
+ public Equalizer getInitialEqualizerSettings() {\r
+ return equalizer;\r
+ }\r
+\r
+ }
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projects / IRC.git / blobdiff