/* * libmad - MPEG audio decoder library * Copyright (C) 2000-2003 Underbit Technologies, Inc. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA * * $Id: layer3.c,v 1.41 2003/05/28 04:24:36 rob Exp $ */# ifdef HAVE_CONFIG_H#  include "config.h"# endif# include "global.h"# include <stdlib.h># include <string.h># ifdef HAVE_ASSERT_H#  include <assert.h># endif# ifdef HAVE_LIMITS_H#  include <limits.h># else#  define CHAR_BIT  8# endif# include "fixed.h"# include "bit.h"# include "stream.h"# include "frame.h"# include "huffman.h"# include "layer3.h"/* --- Layer III ----------------------------------------------------------- */enum {  count1table_select = 0x01,  scalefac_scale     = 0x02,  preflag	     = 0x04,  mixed_block_flag   = 0x08};enum {  I_STEREO  = 0x1,  MS_STEREO = 0x2};struct sideinfo {  unsigned int main_data_begin;  unsigned int private_bits;  unsigned char scfsi[2];  struct granule {    struct channel {      /* from side info */      unsigned short part2_3_length;      unsigned short big_values;      unsigned short global_gain;      unsigned short scalefac_compress;      unsigned char flags;      unsigned char block_type;      unsigned char table_select[3];      unsigned char subblock_gain[3];      unsigned char region0_count;      unsigned char region1_count;      /* from main_data */      unsigned char scalefac[39];	/* scalefac_l and/or scalefac_s */    } ch[2];  } gr[2];};/* * scalefactor bit lengths * derived from section 2.4.2.7 of ISO/IEC 11172-3 */staticstruct {  unsigned char slen1;  unsigned char slen2;} const sflen_table[16] = {  { 0, 0 }, { 0, 1 }, { 0, 2 }, { 0, 3 },  { 3, 0 }, { 1, 1 }, { 1, 2 }, { 1, 3 },  { 2, 1 }, { 2, 2 }, { 2, 3 }, { 3, 1 },  { 3, 2 }, { 3, 3 }, { 4, 2 }, { 4, 3 }};/* * number of LSF scalefactor band values * derived from section 2.4.3.2 of ISO/IEC 13818-3 */staticunsigned char const nsfb_table[6][3][4] = {  { {  6,  5,  5, 5 },    {  9,  9,  9, 9 },    {  6,  9,  9, 9 } },  { {  6,  5,  7, 3 },    {  9,  9, 12, 6 },    {  6,  9, 12, 6 } },  { { 11, 10,  0, 0 },    { 18, 18,  0, 0 },    { 15, 18,  0, 0 } },  { {  7,  7,  7, 0 },    { 12, 12, 12, 0 },    {  6, 15, 12, 0 } },  { {  6,  6,  6, 3 },    { 12,  9,  9, 6 },    {  6, 12,  9, 6 } },  { {  8,  8,  5, 0 },    { 15, 12,  9, 0 },    {  6, 18,  9, 0 } }};/* * MPEG-1 scalefactor band widths * derived from Table B.8 of ISO/IEC 11172-3 */staticunsigned char const sfb_48000_long[] = {   4,  4,  4,  4,  4,  4,  6,  6,  6,   8,  10,  12, 16, 18, 22, 28, 34, 40, 46, 54,  54, 192};staticunsigned char const sfb_44100_long[] = {   4,  4,  4,  4,  4,  4,  6,  6,  8,   8,  10,  12, 16, 20, 24, 28, 34, 42, 50, 54,  76, 158};staticunsigned char const sfb_32000_long[] = {   4,  4,  4,  4,  4,  4,  6,  6,  8,  10,  12,  16, 20, 24, 30, 38, 46, 56, 68, 84, 102,  26};staticunsigned char const sfb_48000_short[] = {   4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  6,   6,  6,  6,  6,  6, 10, 10, 10, 12, 12, 12, 14, 14,  14, 16, 16, 16, 20, 20, 20, 26, 26, 26, 66, 66, 66};staticunsigned char const sfb_44100_short[] = {   4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  6,   6,  6,  8,  8,  8, 10, 10, 10, 12, 12, 12, 14, 14,  14, 18, 18, 18, 22, 22, 22, 30, 30, 30, 56, 56, 56};staticunsigned char const sfb_32000_short[] = {   4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  6,   6,  6,  8,  8,  8, 12, 12, 12, 16, 16, 16, 20, 20,  20, 26, 26, 26, 34, 34, 34, 42, 42, 42, 12, 12, 12};staticunsigned char const sfb_48000_mixed[] = {  /* long */   4,  4,  4,  4,  4,  4,  6,  6,  /* short */  4,  4,  4,  6,  6,  6,  6,  6,  6, 10,              10, 10, 12, 12, 12, 14, 14, 14, 16, 16,              16, 20, 20, 20, 26, 26, 26, 66, 66, 66};staticunsigned char const sfb_44100_mixed[] = {  /* long */   4,  4,  4,  4,  4,  4,  6,  6,  /* short */  4,  4,  4,  6,  6,  6,  8,  8,  8, 10,              10, 10, 12, 12, 12, 14, 14, 14, 18, 18,              18, 22, 22, 22, 30, 30, 30, 56, 56, 56};staticunsigned char const sfb_32000_mixed[] = {  /* long */   4,  4,  4,  4,  4,  4,  6,  6,  /* short */  4,  4,  4,  6,  6,  6,  8,  8,  8, 12,              12, 12, 16, 16, 16, 20, 20, 20, 26, 26,              26, 34, 34, 34, 42, 42, 42, 12, 12, 12};/* * MPEG-2 scalefactor band widths * derived from Table B.2 of ISO/IEC 13818-3 */staticunsigned char const sfb_24000_long[] = {   6,  6,  6,  6,  6,  6,  8, 10, 12,  14,  16,  18, 22, 26, 32, 38, 46, 54, 62, 70,  76,  36};staticunsigned char const sfb_22050_long[] = {   6,  6,  6,  6,  6,  6,  8, 10, 12,  14,  16,  20, 24, 28, 32, 38, 46, 52, 60, 68,  58,  54};# define sfb_16000_long  sfb_22050_longstaticunsigned char const sfb_24000_short[] = {   4,  4,  4,  4,  4,  4,  4,  4,  4,  6,  6,  6,  8,   8,  8, 10, 10, 10, 12, 12, 12, 14, 14, 14, 18, 18,  18, 24, 24, 24, 32, 32, 32, 44, 44, 44, 12, 12, 12};staticunsigned char const sfb_22050_short[] = {   4,  4,  4,  4,  4,  4,  4,  4,  4,  6,  6,  6,  6,   6,  6,  8,  8,  8, 10, 10, 10, 14, 14, 14, 18, 18,  18, 26, 26, 26, 32, 32, 32, 42, 42, 42, 18, 18, 18};staticunsigned char const sfb_16000_short[] = {   4,  4,  4,  4,  4,  4,  4,  4,  4,  6,  6,  6,  8,   8,  8, 10, 10, 10, 12, 12, 12, 14, 14, 14, 18, 18,  18, 24, 24, 24, 30, 30, 30, 40, 40, 40, 18, 18, 18};staticunsigned char const sfb_24000_mixed[] = {  /* long */   6,  6,  6,  6,  6,  6,  /* short */  6,  6,  6,  8,  8,  8, 10, 10, 10, 12,              12, 12, 14, 14, 14, 18, 18, 18, 24, 24,              24, 32, 32, 32, 44, 44, 44, 12, 12, 12};staticunsigned char const sfb_22050_mixed[] = {  /* long */   6,  6,  6,  6,  6,  6,  /* short */  6,  6,  6,  6,  6,  6,  8,  8,  8, 10,              10, 10, 14, 14, 14, 18, 18, 18, 26, 26,              26, 32, 32, 32, 42, 42, 42, 18, 18, 18};staticunsigned char const sfb_16000_mixed[] = {  /* long */   6,  6,  6,  6,  6,  6,  /* short */  6,  6,  6,  8,  8,  8, 10, 10, 10, 12,              12, 12, 14, 14, 14, 18, 18, 18, 24, 24,              24, 30, 30, 30, 40, 40, 40, 18, 18, 18};/* * MPEG 2.5 scalefactor band widths * derived from public sources */# define sfb_12000_long  sfb_16000_long# define sfb_11025_long  sfb_12000_longstaticunsigned char const sfb_8000_long[] = {  12, 12, 12, 12, 12, 12, 16, 20, 24,  28,  32,  40, 48, 56, 64, 76, 90,  2,  2,  2,   2,   2};# define sfb_12000_short  sfb_16000_short# define sfb_11025_short  sfb_12000_shortstaticunsigned char const sfb_8000_short[] = {   8,  8,  8,  8,  8,  8,  8,  8,  8, 12, 12, 12, 16,  16, 16, 20, 20, 20, 24, 24, 24, 28, 28, 28, 36, 36,  36,  2,  2,  2,  2,  2,  2,  2,  2,  2, 26, 26, 26};# define sfb_12000_mixed  sfb_16000_mixed# define sfb_11025_mixed  sfb_12000_mixed/* the 8000 Hz short block scalefactor bands do not break after   the first 36 frequency lines, so this is probably wrong */staticunsigned char const sfb_8000_mixed[] = {  /* long */  12, 12, 12,  /* short */  4,  4,  4,  8,  8,  8, 12, 12, 12, 16, 16, 16,              20, 20, 20, 24, 24, 24, 28, 28, 28, 36, 36, 36,               2,  2,  2,  2,  2,  2,  2,  2,  2, 26, 26, 26};staticstruct {  unsigned char const *l;  unsigned char const *s;  unsigned char const *m;} const sfbwidth_table[9] = {  { sfb_48000_long, sfb_48000_short, sfb_48000_mixed },  { sfb_44100_long, sfb_44100_short, sfb_44100_mixed },  { sfb_32000_long, sfb_32000_short, sfb_32000_mixed },  { sfb_24000_long, sfb_24000_short, sfb_24000_mixed },  { sfb_22050_long, sfb_22050_short, sfb_22050_mixed },  { sfb_16000_long, sfb_16000_short, sfb_16000_mixed },  { sfb_12000_long, sfb_12000_short, sfb_12000_mixed },  { sfb_11025_long, sfb_11025_short, sfb_11025_mixed },  {  sfb_8000_long,  sfb_8000_short,  sfb_8000_mixed }};/* * scalefactor band preemphasis (used only when preflag is set) * derived from Table B.6 of ISO/IEC 11172-3 */staticunsigned char const pretab[22] = {  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 3, 3, 3, 2, 0};/* * table for requantization * * rq_table[x].mantissa * 2^(rq_table[x].exponent) = x^(4/3) */staticstruct fixedfloat {  unsigned long mantissa  : 27;  unsigned short exponent :  5;} const rq_table[8207] = {# include "rq_table.dat"};/* * fractional powers of two * used for requantization and joint stereo decoding * * root_table[3 + x] = 2^(x/4) */staticmad_fixed_t const root_table[7] = {  MAD_F(0x09837f05) /* 2^(-3/4) == 0.59460355750136 */,  MAD_F(0x0b504f33) /* 2^(-2/4) == 0.70710678118655 */,  MAD_F(0x0d744fcd) /* 2^(-1/4) == 0.84089641525371 */,  MAD_F(0x10000000) /* 2^( 0/4) == 1.00000000000000 */,  MAD_F(0x1306fe0a) /* 2^(+1/4) == 1.18920711500272 */,  MAD_F(0x16a09e66) /* 2^(+2/4) == 1.41421356237310 */,  MAD_F(0x1ae89f99) /* 2^(+3/4) == 1.68179283050743 */};/* * coefficients for aliasing reduction * derived from Table B.9 of ISO/IEC 11172-3 * *  c[]  = { -0.6, -0.535, -0.33, -0.185, -0.095, -0.041, -0.0142, -0.0037 } * cs[i] =    1 / sqrt(1 + c[i]^2) * ca[i] = c[i] / sqrt(1 + c[i]^2) */staticmad_fixed_t const cs[8] = {  +MAD_F(0x0db84a81) /* +0.857492926 */, +MAD_F(0x0e1b9d7f) /* +0.881741997 */,  +MAD_F(0x0f31adcf) /* +0.949628649 */, +MAD_F(0x0fbba815) /* +0.983314592 */,  +MAD_F(0x0feda417) /* +0.995517816 */, +MAD_F(0x0ffc8fc8) /* +0.999160558 */,  +MAD_F(0x0fff964c) /* +0.999899195 */, +MAD_F(0x0ffff8d3) /* +0.999993155 */};staticmad_fixed_t const ca[8] = {  -MAD_F(0x083b5fe7) /* -0.514495755 */, -MAD_F(0x078c36d2) /* -0.471731969 */,  -MAD_F(0x05039814) /* -0.313377454 */, -MAD_F(0x02e91dd1) /* -0.181913200 */,  -MAD_F(0x0183603a) /* -0.094574193 */, -MAD_F(0x00a7cb87) /* -0.040965583 */,  -MAD_F(0x003a2847) /* -0.014198569 */, -MAD_F(0x000f27b4) /* -0.003699975 */};/* * IMDCT coefficients for short blocks * derived from section 2.4.3.4.10.2 of ISO/IEC 11172-3 * * imdct_s[i/even][k] = cos((PI / 24) * (2 *       (i / 2) + 7) * (2 * k + 1)) * imdct_s[i /odd][k] = cos((PI / 24) * (2 * (6 + (i-1)/2) + 7) * (2 * k + 1)) */staticmad_fixed_t const imdct_s[6][6] = {# include "imdct_s.dat"};# if !defined(ASO_IMDCT)/* * windowing coefficients for long blocks * derived from section 2.4.3.4.10.3 of ISO/IEC 11172-3 * * window_l[i] = sin((PI / 36) * (i + 1/2)) */staticmad_fixed_t const window_l[36] = {  MAD_F(0x00b2aa3e) /* 0.043619387 */, MAD_F(0x0216a2a2) /* 0.130526192 */,  MAD_F(0x03768962) /* 0.216439614 */, MAD_F(0x04cfb0e2) /* 0.300705800 */,  MAD_F(0x061f78aa) /* 0.382683432 */, MAD_F(0x07635284) /* 0.461748613 */,  MAD_F(0x0898c779) /* 0.537299608 */, MAD_F(0x09bd7ca0) /* 0.608761429 */,  MAD_F(0x0acf37ad) /* 0.675590208 */, MAD_F(0x0bcbe352) /* 0.737277337 */,  MAD_F(0x0cb19346) /* 0.793353340 */, MAD_F(0x0d7e8807) /* 0.843391446 */,  MAD_F(0x0e313245) /* 0.887010833 */, MAD_F(0x0ec835e8) /* 0.923879533 */,  MAD_F(0x0f426cb5) /* 0.953716951 */, MAD_F(0x0f9ee890) /* 0.976296007 */,  MAD_F(0x0fdcf549) /* 0.991444861 */, MAD_F(0x0ffc19fd) /* 0.999048222 */,  MAD_F(0x0ffc19fd) /* 0.999048222 */, MAD_F(0x0fdcf549) /* 0.991444861 */,  MAD_F(0x0f9ee890) /* 0.976296007 */, MAD_F(0x0f426cb5) /* 0.953716951 */,  MAD_F(0x0ec835e8) /* 0.923879533 */, MAD_F(0x0e313245) /* 0.887010833 */,  MAD_F(0x0d7e8807) /* 0.843391446 */, MAD_F(0x0cb19346) /* 0.793353340 */,  MAD_F(0x0bcbe352) /* 0.737277337 */, MAD_F(0x0acf37ad) /* 0.675590208 */,  MAD_F(0x09bd7ca0) /* 0.608761429 */, MAD_F(0x0898c779) /* 0.537299608 */,  MAD_F(0x07635284) /* 0.461748613 */, MAD_F(0x061f78aa) /* 0.382683432 */,  MAD_F(0x04cfb0e2) /* 0.300705800 */, MAD_F(0x03768962) /* 0.216439614 */,  MAD_F(0x0216a2a2) /* 0.130526192 */, MAD_F(0x00b2aa3e) /* 0.043619387 */,};# endif  /* ASO_IMDCT *//* * windowing coefficients for short blocks * derived from section 2.4.3.4.10.3 of ISO/IEC 11172-3 * * window_s[i] = sin((PI / 12) * (i + 1/2)) */staticmad_fixed_t const window_s[12] = {  MAD_F(0x0216a2a2) /* 0.130526192 */, MAD_F(0x061f78aa) /* 0.382683432 */,  MAD_F(0x09bd7ca0) /* 0.608761429 */, MAD_F(0x0cb19346) /* 0.793353340 */,  MAD_F(0x0ec835e8) /* 0.923879533 */, MAD_F(0x0fdcf549) /* 0.991444861 */,  MAD_F(0x0fdcf549) /* 0.991444861 */, MAD_F(0x0ec835e8) /* 0.923879533 */,  MAD_F(0x0cb19346) /* 0.793353340 */, MAD_F(0x09bd7ca0) /* 0.608761429 */,  MAD_F(0x061f78aa) /* 0.382683432 */, MAD_F(0x0216a2a2) /* 0.130526192 */,};/* * coefficients for intensity stereo processing * derived from section 2.4.3.4.9.3 of ISO/IEC 11172-3 * * is_ratio[i] = tan(i * (PI / 12)) * is_table[i] = is_ratio[i] / (1 + is_ratio[i]) */staticmad_fixed_t const is_table[7] = {  MAD_F(0x00000000) /* 0.000000000 */,  MAD_F(0x0361962f) /* 0.211324865 */,  MAD_F(0x05db3d74) /* 0.366025404 */,  MAD_F(0x08000000) /* 0.500000000 */,  MAD_F(0x0a24c28c) /* 0.633974596 */,  MAD_F(0x0c9e69d1) /* 0.788675135 */,  MAD_F(0x10000000) /* 1.000000000 */};/* * coefficients for LSF intensity stereo processing * derived from section 2.4.3.2 of ISO/IEC 13818-3 * * is_lsf_table[0][i] = (1 / sqrt(sqrt(2)))^(i + 1) * is_lsf_table[1][i] = (1 /      sqrt(2)) ^(i + 1) */staticmad_fixed_t const is_lsf_table[2][15] = {  {    MAD_F(0x0d744fcd) /* 0.840896415 */,    MAD_F(0x0b504f33) /* 0.707106781 */,    MAD_F(0x09837f05) /* 0.594603558 */,    MAD_F(0x08000000) /* 0.500000000 */,    MAD_F(0x06ba27e6) /* 0.420448208 */,    MAD_F(0x05a8279a) /* 0.353553391 */,    MAD_F(0x04c1bf83) /* 0.297301779 */,    MAD_F(0x04000000) /* 0.250000000 */,    MAD_F(0x035d13f3) /* 0.210224104 */,    MAD_F(0x02d413cd) /* 0.176776695 */,    MAD_F(0x0260dfc1) /* 0.148650889 */,    MAD_F(0x02000000) /* 0.125000000 */,    MAD_F(0x01ae89fa) /* 0.105112052 */,    MAD_F(0x016a09e6) /* 0.088388348 */,    MAD_F(0x01306fe1) /* 0.074325445 */  }, {    MAD_F(0x0b504f33) /* 0.707106781 */,    MAD_F(0x08000000) /* 0.500000000 */,    MAD_F(0x05a8279a) /* 0.353553391 */,    MAD_F(0x04000000) /* 0.250000000 */,    MAD_F(0x02d413cd) /* 0.176776695 */,    MAD_F(0x02000000) /* 0.125000000 */,    MAD_F(0x016a09e6) /* 0.088388348 */,    MAD_F(0x01000000) /* 0.062500000 */,    MAD_F(0x00b504f3) /* 0.044194174 */,    MAD_F(0x00800000) /* 0.031250000 */,    MAD_F(0x005a827a) /* 0.022097087 */,    MAD_F(0x00400000) /* 0.015625000 */,    MAD_F(0x002d413d) /* 0.011048543 */,    MAD_F(0x00200000) /* 0.007812500 */,    MAD_F(0x0016a09e) /* 0.005524272 */  }};