/* * 11/19/04 1.0 moved to LGPL. * 16/11/99 Renamed class, added javadoc, and changed table * name from String to 3 chars. mdm@techie.com * 02/15/99 Java Conversion by E.B, javalayer@javazoom.net * * 04/19/97 : Adapted from the ISO MPEG Audio Subgroup Software Simulation * Group's public c source for its MPEG audio decoder. Miscellaneous * changes by Jeff Tsay (ctsay@pasteur.eecs.berkeley.edu). *----------------------------------------------------------------------- * Copyright (c) 1991 MPEG/audio software simulation group, All Rights Reserved * MPEG/audio coding/decoding software, work in progress * NOT for public distribution until verified and approved by the * MPEG/audio committee. For further information, please contact * Davis Pan, 508-493-2241, e-mail: pan@3d.enet.dec.com * * VERSION 4.1 * changes made since last update: * date programmers comment * 27.2.92 F.O.Witte (ITT Intermetall) * 8/24/93 M. Iwadare Changed for 1 pass decoding. * 7/14/94 J. Koller useless 'typedef' before huffcodetab removed *----------------------------------------------------------------------- * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU Library General Public License as published * by the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. *---------------------------------------------------------------------- */ /** * Class to implements Huffman decoder. */ @LATTICE("FIELD>> 4; y[0] = ht[htIdx].val[point][1] & 0xf; error = 0; break; } // hget1bit() is called thousands of times, and so needs to be // ultra fast. /* * if (bitIndex==bitsAvailable) { bitsAvailable = br.readBits(bits, 32); * bitIndex = 0; } */ // if (bits[bitIndex++]!=0) if (br.hget1bit() != 0) { TERMINATE: while (ht[htIdx].val[point][1] >= MXOFF) point += ht[htIdx].val[point][1]; point += ht[htIdx].val[point][1]; } else { TERMINATE: while (ht[htIdx].val[point][0] >= MXOFF) point += ht[htIdx].val[point][0]; point += ht[htIdx].val[point][0]; } level >>>= 1; // MDM: ht[0] is always 0; } while ((level != 0) || (point < 0 /* ht[0].treelen */)); // put back any bits not consumed /* * int unread = (bitsAvailable-bitIndex); if (unread>0) * br.rewindNbits(unread); */ /* Process sign encodings for quadruples tables. */ // System.out.println(ht[htIdx].tablename); if (ht[htIdx].tablename0 == '3' && (ht[htIdx].tablename1 == '2' || ht[htIdx].tablename1 == '3')) { v[0] = (y[0] >> 3) & 1; w[0] = (y[0] >> 2) & 1; x[0] = (y[0] >> 1) & 1; y[0] = y[0] & 1; /* * v, w, x and y are reversed in the bitstream. switch them around to make * test bistream work. */ if (v[0] != 0) if (br.hget1bit() != 0) v[0] = -v[0]; if (w[0] != 0) if (br.hget1bit() != 0) w[0] = -w[0]; if (x[0] != 0) if (br.hget1bit() != 0) x[0] = -x[0]; if (y[0] != 0) if (br.hget1bit() != 0) y[0] = -y[0]; } else { // Process sign and escape encodings for dual tables. // x and y are reversed in the test bitstream. // Reverse x and y here to make test bitstream work. if (ht[htIdx].linbits != 0) if ((ht[htIdx].xlen - 1) == x[0]) x[0] += br.hgetbits(ht[htIdx].linbits); if (x[0] != 0) if (br.hget1bit() != 0) x[0] = -x[0]; if (ht[htIdx].linbits != 0) if ((ht[htIdx].ylen - 1) == y[0]) y[0] += br.hgetbits(ht[htIdx].linbits); if (y[0] != 0) if (br.hget1bit() != 0) y[0] = -y[0]; } return error; } public static void inithuff() { if (ht != null) return; ht = new huffcodetab[HTN]; ht[0] = new huffcodetab("0 ", 0, 0, 0, 0, -1, null, null, ValTab0, 0); ht[1] = new huffcodetab("1 ", 2, 2, 0, 0, -1, null, null, ValTab1, 7); ht[2] = new huffcodetab("2 ", 3, 3, 0, 0, -1, null, null, ValTab2, 17); ht[3] = new huffcodetab("3 ", 3, 3, 0, 0, -1, null, null, ValTab3, 17); ht[4] = new huffcodetab("4 ", 0, 0, 0, 0, -1, null, null, ValTab4, 0); ht[5] = new huffcodetab("5 ", 4, 4, 0, 0, -1, null, null, ValTab5, 31); ht[6] = new huffcodetab("6 ", 4, 4, 0, 0, -1, null, null, ValTab6, 31); ht[7] = new huffcodetab("7 ", 6, 6, 0, 0, -1, null, null, ValTab7, 71); ht[8] = new huffcodetab("8 ", 6, 6, 0, 0, -1, null, null, ValTab8, 71); ht[9] = new huffcodetab("9 ", 6, 6, 0, 0, -1, null, null, ValTab9, 71); ht[10] = new huffcodetab("10 ", 8, 8, 0, 0, -1, null, null, ValTab10, 127); ht[11] = new huffcodetab("11 ", 8, 8, 0, 0, -1, null, null, ValTab11, 127); ht[12] = new huffcodetab("12 ", 8, 8, 0, 0, -1, null, null, ValTab12, 127); ht[13] = new huffcodetab("13 ", 16, 16, 0, 0, -1, null, null, ValTab13, 511); ht[14] = new huffcodetab("14 ", 0, 0, 0, 0, -1, null, null, ValTab14, 0); ht[15] = new huffcodetab("15 ", 16, 16, 0, 0, -1, null, null, ValTab15, 511); ht[16] = new huffcodetab("16 ", 16, 16, 1, 1, -1, null, null, ValTab16, 511); ht[17] = new huffcodetab("17 ", 16, 16, 2, 3, 16, null, null, ValTab16, 511); ht[18] = new huffcodetab("18 ", 16, 16, 3, 7, 16, null, null, ValTab16, 511); ht[19] = new huffcodetab("19 ", 16, 16, 4, 15, 16, null, null, ValTab16, 511); ht[20] = new huffcodetab("20 ", 16, 16, 6, 63, 16, null, null, ValTab16, 511); ht[21] = new huffcodetab("21 ", 16, 16, 8, 255, 16, null, null, ValTab16, 511); ht[22] = new huffcodetab("22 ", 16, 16, 10, 1023, 16, null, null, ValTab16, 511); ht[23] = new huffcodetab("23 ", 16, 16, 13, 8191, 16, null, null, ValTab16, 511); ht[24] = new huffcodetab("24 ", 16, 16, 4, 15, -1, null, null, ValTab24, 512); ht[25] = new huffcodetab("25 ", 16, 16, 5, 31, 24, null, null, ValTab24, 512); ht[26] = new huffcodetab("26 ", 16, 16, 6, 63, 24, null, null, ValTab24, 512); ht[27] = new huffcodetab("27 ", 16, 16, 7, 127, 24, null, null, ValTab24, 512); ht[28] = new huffcodetab("28 ", 16, 16, 8, 255, 24, null, null, ValTab24, 512); ht[29] = new huffcodetab("29 ", 16, 16, 9, 511, 24, null, null, ValTab24, 512); ht[30] = new huffcodetab("30 ", 16, 16, 11, 2047, 24, null, null, ValTab24, 512); ht[31] = new huffcodetab("31 ", 16, 16, 13, 8191, 24, null, null, ValTab24, 512); ht[32] = new huffcodetab("32 ", 1, 16, 0, 0, -1, null, null, ValTab32, 31); ht[33] = new huffcodetab("33 ", 1, 16, 0, 0, -1, null, null, ValTab33, 31); } }