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/* * mad - MPEG audio decoder * Copyright (C) 2000-2001 Robert Leslie * * 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 1.3 2001-11-06 17:01:28 simons Exp $ */ # ifdef HAVE_CONFIG_H # include "config.h" # endif # include "global.h" # ifndef EMBED # include <string.h> # include <assert.h> # include <stdio.h> # ifdef HAVE_LIMITS_H # include <limits.h> # else # define CHAR_BIT 8 # endif #else # define assert(x) # 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 }; 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 */ static struct { 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 */ static unsigned 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 */ static unsigned 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 }; static unsigned 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 }; static unsigned 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 }; static unsigned 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 }; static unsigned 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 }; static unsigned 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 }; static unsigned 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 }; static unsigned 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 }; static unsigned 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 */ static unsigned 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 }; static unsigned 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_long static unsigned 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 }; static unsigned 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 }; static unsigned 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 }; static unsigned 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 }; static unsigned 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 }; static unsigned 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_long static unsigned 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_short static unsigned 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 */ static unsigned 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 }; static struct { 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 */ static unsigned 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) * MM: shortened table */ #define RQ_START_BITS 7 static struct fixedfloat { unsigned long mantissa : 27; unsigned short exponent : 5; } const rq_table[512] = { # include "rq_short.dat" }; /* * fractional powers of two * used for requantization and joint stereo decoding * * root_table[3 + x] = 2^(x/4) */ static mad_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) */ static mad_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 */ }; static mad_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)) */ static mad_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)) */ static mad_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)) */ static mad_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]) */ static mad_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) */ static mad_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 */ } }; /* * NAME: III_sideinfo() * DESCRIPTION: decode frame side information from a bitstream */ static enum mad_error III_sideinfo(struct mad_bitptr *ptr, unsigned int nch, int lsf, struct sideinfo *si, unsigned int *data_bitlen, unsigned int *priv_bitlen) { unsigned int ngr, gr, ch, i; enum mad_error result = 0; *data_bitlen = 0; *priv_bitlen = lsf ? ((nch == 1) ? 1 : 2) : ((nch == 1) ? 5 : 3); si->main_data_begin = mad_bit_read(ptr, lsf ? 8 : 9); si->private_bits = mad_bit_read(ptr, *priv_bitlen); ngr = 1; if (!lsf) { ngr = 2; for (ch = 0; ch < nch; ++ch) si->scfsi[ch] = mad_bit_read(ptr, 4); } for (gr = 0; gr < ngr; ++gr) { struct granule *granule = &si->gr[gr]; for (ch = 0; ch < nch; ++ch) { struct channel *channel = &granule->ch[ch]; channel->part2_3_length = mad_bit_read(ptr, 12); channel->big_values = mad_bit_read(ptr, 9); channel->global_gain = mad_bit_read(ptr, 8); channel->scalefac_compress = mad_bit_read(ptr, lsf ? 9 : 4); *data_bitlen += channel->part2_3_length; if (channel->big_values > 288 && result == 0) result = MAD_ERROR_BADBIGVALUES; channel->flags = 0; /* window_switching_flag */ if (mad_bit_read(ptr, 1)) { channel->block_type = mad_bit_read(ptr, 2); if (channel->block_type == 0 && result == 0) result = MAD_ERROR_BADBLOCKTYPE; if (!lsf && channel->block_type == 2 && si->scfsi[ch] && result == 0) result = MAD_ERROR_BADSCFSI; channel->region0_count = 7; channel->region1_count = 36; if (mad_bit_read(ptr, 1)) channel->flags |= mixed_block_flag; else if (channel->block_type == 2) channel->region0_count = 8; for (i = 0; i < 2; ++i) channel->table_select[i] = mad_bit_read(ptr, 5); # if defined(DEBUG) channel->table_select[2] = 4; /* not used */ # endif for (i = 0; i < 3; ++i) channel->subblock_gain[i] = mad_bit_read(ptr, 3); } else { channel->block_type = 0; for (i = 0; i < 3; ++i) channel->table_select[i] = mad_bit_read(ptr, 5); channel->region0_count = mad_bit_read(ptr, 4); channel->region1_count = mad_bit_read(ptr, 3); } /* [preflag,] scalefac_scale, count1table_select */ channel->flags |= mad_bit_read(ptr, lsf ? 2 : 3); } } return result; } /* * NAME: III_scalefactors_lsf() * DESCRIPTION: decode channel scalefactors for LSF from a bitstream */ static unsigned int III_scalefactors_lsf(struct mad_bitptr *ptr, struct channel *channel, struct channel *gr1ch, int mode_extension) { struct mad_bitptr start; unsigned int scalefac_compress, index, slen[4], part, n, i; unsigned char const *nsfb; start = *ptr; scalefac_compress = channel->scalefac_compress; index = (channel->block_type == 2) ? ((channel->flags & mixed_block_flag) ? 2 : 1) : 0; if (!((mode_extension & 0x1) && gr1ch)) { if (scalefac_compress < 400) { slen[0] = (scalefac_compress >> 4) / 5; slen[1] = (scalefac_compress >> 4) % 5; slen[2] = (scalefac_compress % 16) >> 2; slen[3] = scalefac_compress % 4; nsfb = nsfb_table[0][index]; } else if (scalefac_compress < 500) { scalefac_compress -= 400; slen[0] = (scalefac_compress >> 2) / 5; slen[1] = (scalefac_compress >> 2) % 5; slen[2] = scalefac_compress % 4; slen[3] = 0; nsfb = nsfb_table[1][index]; } else { scalefac_compress -= 500; slen[0] = scalefac_compress / 3; slen[1] = scalefac_compress % 3; slen[2] = 0; slen[3] = 0; channel->flags |= preflag; nsfb = nsfb_table[2][index]; } n = 0; for (part = 0; part < 4; ++part) { for (i = 0; i < nsfb[part]; ++i) channel->scalefac[n++] = mad_bit_read(ptr, slen[part]); } while (n < 39) channel->scalefac[n++] = 0; } else { /* (mode_extension & 0x1) && gr1ch (i.e. ch == 1) */ scalefac_compress >>= 1; if (scalefac_compress < 180) { slen[0] = scalefac_compress / 36; slen[1] = (scalefac_compress % 36) / 6; slen[2] = (scalefac_compress % 36) % 6; slen[3] = 0; nsfb = nsfb_table[3][index]; } else if (scalefac_compress < 244) { scalefac_compress -= 180; slen[0] = (scalefac_compress % 64) >> 4; slen[1] = (scalefac_compress % 16) >> 2; slen[2] = scalefac_compress % 4; slen[3] = 0; nsfb = nsfb_table[4][index]; } else { scalefac_compress -= 244; slen[0] = scalefac_compress / 3; slen[1] = scalefac_compress % 3; slen[2] = 0; slen[3] = 0; nsfb = nsfb_table[5][index]; } n = 0; for (part = 0; part < 4; ++part) { unsigned int max, is_pos; max = (1 << slen[part]) - 1; for (i = 0; i < nsfb[part]; ++i) { is_pos = mad_bit_read(ptr, slen[part]); channel->scalefac[n] = is_pos; gr1ch->scalefac[n++] = (is_pos == max); } } while (n < 39) { channel->scalefac[n] = 0; gr1ch->scalefac[n++] = 0; /* apparently not illegal */ } } return mad_bit_length(&start, ptr); } /* * NAME: III_scalefactors() * DESCRIPTION: decode channel scalefactors of one granule from a bitstream */ static unsigned int III_scalefactors(struct mad_bitptr *ptr, struct channel *channel, struct channel const *gr0ch, unsigned int scfsi) { struct mad_bitptr start; unsigned int slen1, slen2, sfbi; start = *ptr; slen1 = sflen_table[channel->scalefac_compress].slen1; slen2 = sflen_table[channel->scalefac_compress].slen2; if (channel->block_type == 2) { unsigned int nsfb; sfbi = 0; nsfb = (channel->flags & mixed_block_flag) ? 8 + 3 * 3 : 6 * 3; while (nsfb--) channel->scalefac[sfbi++] = mad_bit_read(ptr, slen1); nsfb = 6 * 3; while (nsfb--) channel->scalefac[sfbi++] = mad_bit_read(ptr, slen2); nsfb = 1 * 3; while (nsfb--) channel->scalefac[sfbi++] = 0; } else { /* channel->block_type != 2 */ if (scfsi & 0x8) { for (sfbi = 0; sfbi < 6; ++sfbi) channel->scalefac[sfbi] = gr0ch->scalefac[sfbi]; } else { for (sfbi = 0; sfbi < 6; ++sfbi) channel->scalefac[sfbi] = mad_bit_read(ptr, slen1); } if (scfsi & 0x4) { for (sfbi = 6; sfbi < 11; ++sfbi) channel->scalefac[sfbi] = gr0ch->scalefac[sfbi]; } else { for (sfbi = 6; sfbi < 11; ++sfbi) channel->scalefac[sfbi] = mad_bit_read(ptr, slen1); } if (scfsi & 0x2) { for (sfbi = 11; sfbi < 16; ++sfbi) channel->scalefac[sfbi] = gr0ch->scalefac[sfbi]; } else { for (sfbi = 11; sfbi < 16; ++sfbi) channel->scalefac[sfbi] = mad_bit_read(ptr, slen2); } if (scfsi & 0x1) { for (sfbi = 16; sfbi < 21; ++sfbi) channel->scalefac[sfbi] = gr0ch->scalefac[sfbi]; } else { for (sfbi = 16; sfbi < 21; ++sfbi) channel->scalefac[sfbi] = mad_bit_read(ptr, slen2); } channel->scalefac[21] = 0; } return mad_bit_length(&start, ptr); } /* * NAME: III_exponents() * DESCRIPTION: calculate scalefactor exponents */ static void III_exponents(struct channel const *channel, unsigned char const *sfbwidth, signed int exponents[39]) { signed int gain; unsigned int scalefac_multiplier, sfbi; gain = (signed int) channel->global_gain - 210; scalefac_multiplier = (channel->flags & scalefac_scale) ? 2 : 1; if (channel->block_type == 2) { unsigned int l; signed int gain0, gain1, gain2; sfbi = l = 0; if (channel->flags & mixed_block_flag) { unsigned int premask; premask = (channel->flags & preflag) ? ~0 : 0; /* long block subbands 0-1 */ while (l < 36) { exponents[sfbi] = gain - (signed int) ((channel->scalefac[sfbi] + (pretab[sfbi] & premask)) << scalefac_multiplier); l += sfbwidth[sfbi++]; } } /* this is probably wrong for 8000 Hz short/mixed blocks */ gain0 = gain - 8 * (signed int) channel->subblock_gain[0]; gain1 = gain - 8 * (signed int) channel->subblock_gain[1]; gain2 = gain - 8 * (signed int) channel->subblock_gain[2]; while (l < 576) { exponents[sfbi + 0] = gain0 - (signed int) (channel->scalefac[sfbi + 0] << scalefac_multiplier); exponents[sfbi + 1] = gain1 - (signed int) (channel->scalefac[sfbi + 1] << scalefac_multiplier); exponents[sfbi + 2] = gain2 - (signed int) (channel->scalefac[sfbi + 2] << scalefac_multiplier); l += 3 * sfbwidth[sfbi]; sfbi += 3; } } else { /* channel->block_type != 2 */ if (channel->flags & preflag) { for (sfbi = 0; sfbi < 22; ++sfbi) { exponents[sfbi] = gain - (signed int) ((channel->scalefac[sfbi] + pretab[sfbi]) << scalefac_multiplier); } } else { for (sfbi = 0; sfbi < 22; ++sfbi) { exponents[sfbi] = gain - (signed int) (channel->scalefac[sfbi] << scalefac_multiplier); } } } } /* * NAME: III_requantize() * DESCRIPTION: requantize one (positive) value */ static mad_fixed_t III_requantize(unsigned int value, signed int exp) { mad_fixed_t requantized; signed int frac; struct fixedfloat const *power; /* * long blocks: * xr[i] = sign(is[i]) * abs(is[i])^(4/3) * * 2^((1/4) * (global_gain - 210)) * * 2^-(scalefac_multiplier * * (scalefac_l[sfb] + preflag * pretab[sfb])) * * short blocks: * xr[i] = sign(is[i]) * abs(is[i])^(4/3) * * 2^((1/4) * (global_gain - 210 - 8 * subblock_gain[w])) * * 2^-(scalefac_multiplier * scalefac_s[sfb][w]) * * where: * scalefac_multiplier = (scalefac_scale + 1) / 2 */ frac = exp % 4; exp /= 4; /* MM: recalculation for short table */ if (value < (1 << RQ_START_BITS)) power = &rq_table[value]; else { int bits = 0, tmp = value; while (tmp != 0) { tmp <<= 1; bits++; } bits -= RQ_START_BITS; value &= ~((1 << bits) - 1); power = &rq_table[value]; } requantized = power->mantissa; exp += power->exponent; if (exp < 0) { if (-exp >= sizeof(mad_fixed_t) * CHAR_BIT) { /* underflow */ requantized = 0; } else requantized >>= -exp; } else { if (exp >= 5) { /* overflow */ # if defined(DEBUG) fprintf(stderr, "requantize overflow (%f * 2^%d)\n", mad_f_todouble(requantized), exp); # endif requantized = MAD_F_MAX; } else requantized <<= exp; } return frac ? mad_f_mul(requantized, root_table[3 + frac]) : requantized; } /* we must take care that sz >= bits and sz < sizeof(long) lest bits == 0 */ # define MASK(cache, sz, bits) \ (((cache) >> ((sz) - (bits))) & ((1 << (bits)) - 1)) # define MASK1BIT(cache, sz) \ ((cache) & (1 << ((sz) - 1))) /* * NAME: III_huffdecode() * DESCRIPTION: decode Huffman code words of one channel of one granule */ static enum mad_error III_huffdecode(struct mad_bitptr *ptr, mad_fixed_t xr[576], struct channel *channel, unsigned char const *sfbwidth, unsigned int part2_length) { signed int exponents[39], exp; signed int const *expptr; struct mad_bitptr peek; signed int bits_left, cachesz; register mad_fixed_t *xrptr; mad_fixed_t const *sfbound; register unsigned long bitcache; bits_left = (signed) channel->part2_3_length - (signed) part2_length; if (bits_left < 0) return MAD_ERROR_BADPART3LEN; III_exponents(channel, sfbwidth, exponents); peek = *ptr; mad_bit_skip(ptr, bits_left); /* align bit reads to byte boundaries */ cachesz = mad_bit_bitsleft(&peek); cachesz += ((32 - 1 - 24) + (24 - cachesz)) & ~7; bitcache = mad_bit_read(&peek, cachesz); bits_left -= cachesz; xrptr = &xr[0]; /* big_values */ { unsigned int region, rcount; struct hufftable const *entry; union huffpair const *table; unsigned int linbits, startbits, big_values, reqhits; mad_fixed_t reqcache[16]; sfbound = xrptr + *sfbwidth++; rcount = channel->region0_count + 1; entry = &mad_huff_pair_table[channel->table_select[region = 0]]; table = entry->table; linbits = entry->linbits; startbits = entry->startbits; if (table == 0) return MAD_ERROR_BADHUFFTABLE; expptr = &exponents[0]; exp = *expptr++; reqhits = 0; big_values = channel->big_values; while (big_values-- && cachesz + bits_left > 0) { union huffpair const *pair; unsigned int clumpsz, value; register mad_fixed_t requantized; if (xrptr == sfbound) { sfbound += *sfbwidth++; /* change table if region boundary */ if (--rcount == 0) { if (region == 0) rcount = channel->region1_count + 1; else rcount = 0; /* all remaining */ entry = &mad_huff_pair_table[channel->table_select[++region]]; table = entry->table; linbits = entry->linbits; startbits = entry->startbits; if (table == 0) return MAD_ERROR_BADHUFFTABLE; } if (exp != *expptr) { exp = *expptr; reqhits = 0; } ++expptr; } if (cachesz < 21) { unsigned int bits; bits = ((32 - 1 - 21) + (21 - cachesz)) & ~7; bitcache = (bitcache << bits) | mad_bit_read(&peek, bits); cachesz += bits; bits_left -= bits; } /* hcod (0..19) */ clumpsz = startbits; pair = &table[MASK(bitcache, cachesz, clumpsz)]; while (!pair->final) { cachesz -= clumpsz; clumpsz = pair->ptr.bits; pair = &table[pair->ptr.offset + MASK(bitcache, cachesz, clumpsz)]; } cachesz -= pair->value.hlen; { int xy_sel; /* MM: joint x and y */ value = pair->value.x; /* x (0..14) and y (0..14) and x (0..1) and y (0..1) */ for (xy_sel = 0; xy_sel < 2; xy_sel++) { if (value == 0) xrptr[xy_sel] = 0; else { if (value == 15 && linbits) { if (cachesz < linbits + 2 - xy_sel) { bitcache = (bitcache << 16) | mad_bit_read(&peek, 16); cachesz += 16; bits_left -= 16; } value += MASK(bitcache, cachesz, linbits); cachesz -= linbits; requantized = III_requantize(value, exp); } else { if (reqhits & (1 << value)) requantized = reqcache[value]; else { reqhits |= (1 << value); requantized = reqcache[value] = III_requantize(value, exp); } } xrptr[xy_sel] = MASK1BIT(bitcache, cachesz--) ? -requantized : requantized; } value = pair->value.y; } } xrptr += 2; } } if (cachesz + bits_left < 0) return MAD_ERROR_BADHUFFDATA; /* big_values overrun */ /* count1 */ { union huffquad const *table; register mad_fixed_t requantized; table = mad_huff_quad_table[channel->flags & count1table_select]; requantized = III_requantize(1, exp); while (cachesz + bits_left > 0 && xrptr <= &xr[572]) { union huffquad const *quad; /* hcod (1..6) */ if (cachesz < 10) { bitcache = (bitcache << 16) | mad_bit_read(&peek, 16); cachesz += 16; bits_left -= 16; } quad = &table[MASK(bitcache, cachesz, 4)]; /* quad tables guaranteed to have at most one extra lookup */ if (!quad->final) { cachesz -= 4; quad = &table[quad->ptr.offset + MASK(bitcache, cachesz, quad->ptr.bits)]; } cachesz -= quad->value.hlen; /* MM: code joined */ { int sel_12; int vw_xy_sel = *((int *) &quad->value); for (sel_12 = 0; sel_12 < 2; sel_12++) { if (xrptr == sfbound) { sfbound += *sfbwidth++; if (exp != *expptr) { exp = *expptr; requantized = III_requantize(1, exp); } ++expptr; } { int tmp = MASK1BIT(bitcache, cachesz--) ? -requantized : requantized; /* v (0..1) or x (0..1) */ xrptr[0] = vw_xy_sel&4 ? tmp : 0; /* w (0..1) or y (0..1) */ xrptr[1] = vw_xy_sel&8 ? tmp : 0; } xrptr += 2; vw_xy_sel >>= 2; } } } if (cachesz + bits_left < 0) { # if 0 && defined(DEBUG) fprintf(stderr, "huffman count1 overrun (%d bits)\n", -(cachesz + bits_left)); # endif /* technically the bitstream is misformatted, but apparently some encoders are just a bit sloppy with stuffing bits */ xrptr -= 4; } } assert(-bits_left <= MAD_BUFFER_GUARD * CHAR_BIT); # if 0 && defined(DEBUG) if (bits_left < 0) fprintf(stderr, "read %d bits too many\n", -bits_left); else if (cachesz + bits_left > 0) fprintf(stderr, "%d stuffing bits\n", cachesz + bits_left); # endif /* rzero */ while (xrptr < &xr[576]) { xrptr[0] = 0; xrptr[1] = 0; xrptr += 2; } return 0; } # undef MASK # undef MASK1BIT /* * NAME: III_reorder() * DESCRIPTION: reorder frequency lines of a short block into subband order */ static void III_reorder(mad_fixed_t xr[576], struct channel const *channel, unsigned char const sfbwidth[39]) { mad_fixed_t tmp[32][3][6]; unsigned int sb, l, sfbi, f, w, sbw[3], sw[3]; /* this is probably wrong for 8000 Hz mixed blocks */ if (channel->flags & mixed_block_flag) sb = 2, sfbi = 3 * 3; else sb = 0, sfbi = 0; for (w = 0; w < 3; ++w) { sbw[w] = sb; sw[w] = 0; } f = sfbwidth[sfbi]; w = 0; for (l = 18 * sb; l < 576; ++l) { tmp[sbw[w]][w][sw[w]++] = xr[l]; if (sw[w] == 6) { sw[w] = 0; ++sbw[w]; } if (--f == 0) { if (++w == 3) w = 0; f = sfbwidth[++sfbi]; } } memcpy(&xr[18 * sb], &tmp[sb], (576 - 18 * sb) * sizeof(mad_fixed_t)); } /* * NAME: III_stereo() * DESCRIPTION: perform joint stereo processing on a granule */ static enum mad_error III_stereo(mad_fixed_t xr[2][576], struct granule const *granule, struct mad_header *header, unsigned char const *sfbwidth) { short modes[39]; unsigned int sfbi, l, n, i; enum { i_stereo = 0x1, ms_stereo = 0x2 }; if (granule->ch[0].block_type != granule->ch[1].block_type || (granule->ch[0].flags & mixed_block_flag) != (granule->ch[1].flags & mixed_block_flag)) return MAD_ERROR_BADSTEREO; for (i = 0; i < 39; ++i) modes[i] = header->mode_extension; /* intensity stereo */ if (header->mode_extension & i_stereo) { struct channel const *right_ch = &granule->ch[1]; mad_fixed_t const *right_xr = xr[1]; unsigned int is_pos; header->flags |= MAD_FLAG_I_STEREO; /* first determine which scalefactor bands are to be processed */ if (right_ch->block_type == 2) { unsigned int lower, start, max, bound[3], w; lower = start = max = bound[0] = bound[1] = bound[2] = 0; sfbi = l = 0; if (right_ch->flags & mixed_block_flag) { while (l < 36) { n = sfbwidth[sfbi++]; for (i = 0; i < n; ++i) { if (right_xr[i]) { lower = sfbi; break; } } right_xr += n; l += n; } start = sfbi; } w = 0; while (l < 576) { n = sfbwidth[sfbi++]; for (i = 0; i < n; ++i) { if (right_xr[i]) { max = bound[w] = sfbi; break; } } right_xr += n; l += n; w = (w + 1) % 3; } if (max) lower = start; /* long blocks */ for (i = 0; i < lower; ++i) modes[i] = header->mode_extension & ~i_stereo; /* short blocks */ w = 0; for (i = start; i < max; ++i) { if (i < bound[w]) modes[i] = header->mode_extension & ~i_stereo; w = (w + 1) % 3; } } else { /* right_ch->block_type != 2 */ unsigned int bound; bound = 0; for (sfbi = l = 0; l < 576; l += n) { n = sfbwidth[sfbi++]; for (i = 0; i < n; ++i) { if (right_xr[i]) { bound = sfbi; break; } } right_xr += n; } for (i = 0; i < bound; ++i) modes[i] = header->mode_extension & ~i_stereo; } /* now do the actual processing */ if (header->flags & MAD_FLAG_LSF_EXT) { unsigned char const *illegal_pos = granule[1].ch[1].scalefac; mad_fixed_t const *lsf_scale; /* intensity_scale */ lsf_scale = is_lsf_table[right_ch->scalefac_compress & 0x1]; for (sfbi = l = 0; l < 576; ++sfbi, l += n) { n = sfbwidth[sfbi]; if (!(modes[sfbi] & i_stereo)) continue; if (illegal_pos[sfbi]) { modes[sfbi] &= ~i_stereo; continue; } is_pos = right_ch->scalefac[sfbi]; for (i = 0; i < n; ++i) { register mad_fixed_t left; left = xr[0][l + i]; if (is_pos == 0) xr[1][l + i] = left; else { register mad_fixed_t opposite; opposite = mad_f_mul(left, lsf_scale[(is_pos - 1) / 2]); if (is_pos & 1) { xr[0][l + i] = opposite; xr[1][l + i] = left; } else xr[1][l + i] = opposite; } } } } else { /* !(header->flags & MAD_FLAG_LSF_EXT) */ for (sfbi = l = 0; l < 576; ++sfbi, l += n) { n = sfbwidth[sfbi]; if (!(modes[sfbi] & i_stereo)) continue; is_pos = right_ch->scalefac[sfbi]; if (is_pos >= 7) { /* illegal intensity position */ modes[sfbi] &= ~i_stereo; continue; } for (i = 0; i < n; ++i) { register mad_fixed_t left; left = xr[0][l + i]; xr[0][l + i] = mad_f_mul(left, is_table[ is_pos]); xr[1][l + i] = mad_f_mul(left, is_table[6 - is_pos]); } } } } /* middle/side stereo */ if (header->mode_extension & ms_stereo) { register mad_fixed_t invsqrt2; header->flags |= MAD_FLAG_MS_STEREO; invsqrt2 = root_table[3 + -2]; for (sfbi = l = 0; l < 576; ++sfbi, l += n) { n = sfbwidth[sfbi]; if (modes[sfbi] != ms_stereo) continue; for (i = 0; i < n; ++i) { register mad_fixed_t m, s; m = xr[0][l + i]; s = xr[1][l + i]; xr[0][l + i] = mad_f_mul(m + s, invsqrt2); /* l = (m + s) / sqrt(2) */ xr[1][l + i] = mad_f_mul(m - s, invsqrt2); /* r = (m - s) / sqrt(2) */ } } } return 0; } /* * NAME: III_aliasreduce() * DESCRIPTION: perform frequency line alias reduction */ static void III_aliasreduce(mad_fixed_t xr[576], int lines) { mad_fixed_t const *bound; int i; bound = &xr[lines]; for (xr += 18; xr < bound; xr += 18) { for (i = 0; i < 8; ++i) { register mad_fixed_t *aptr, *bptr, a, b; register mad_fixed64hi_t hi; register mad_fixed64lo_t lo; aptr = &xr[-1 - i]; bptr = &xr[ i]; a = *aptr; b = *bptr; # if defined(ASO_ZEROCHECK) if (a | b) { # endif MAD_F_ML0(hi, lo, a, cs[i]); MAD_F_MLA(hi, lo, -b, ca[i]); *aptr = MAD_F_MLZ(hi, lo); MAD_F_ML0(hi, lo, b, cs[i]); MAD_F_MLA(hi, lo, a, ca[i]); *bptr = MAD_F_MLZ(hi, lo); # if defined(ASO_ZEROCHECK) } # endif } } } # if defined(ASO_IMDCT) void III_imdct_l(mad_fixed_t const [18], mad_fixed_t [36], unsigned int); # else /* * NAME: imdct36 * DESCRIPTION: perform X[18]->x[36] IMDCT */ static inline void imdct36(mad_fixed_t const X[18], mad_fixed_t x[36]) { mad_fixed_t t0, t1, t2, t3, t4, t5, t6, t7; mad_fixed_t t8, t9, t10, t11, t12, t13, t14, t15; register mad_fixed64hi_t hi; register mad_fixed64lo_t lo; MAD_F_ML0(hi, lo, X[4], MAD_F(0x0ec835e8)); MAD_F_MLA(hi, lo, X[13], MAD_F(0x061f78aa)); t6 = MAD_F_MLZ(hi, lo); MAD_F_MLA(hi, lo, (t14 = X[1] - X[10]), -MAD_F(0x061f78aa)); MAD_F_MLA(hi, lo, (t15 = X[7] + X[16]), -MAD_F(0x0ec835e8)); t0 = MAD_F_MLZ(hi, lo); MAD_F_MLA(hi, lo, (t8 = X[0] - X[11] - X[12]), MAD_F(0x0216a2a2)); MAD_F_MLA(hi, lo, (t9 = X[2] - X[9] - X[14]), MAD_F(0x09bd7ca0)); MAD_F_MLA(hi, lo, (t10 = X[3] - X[8] - X[15]), -MAD_F(0x0cb19346)); MAD_F_MLA(hi, lo, (t11 = X[5] - X[6] - X[17]), -MAD_F(0x0fdcf549)); x[7] = MAD_F_MLZ(hi, lo); x[10] = -x[7]; MAD_F_ML0(hi, lo, t8, -MAD_F(0x0cb19346)); MAD_F_MLA(hi, lo, t9, MAD_F(0x0fdcf549)); MAD_F_MLA(hi, lo, t10, MAD_F(0x0216a2a2)); MAD_F_MLA(hi, lo, t11, -MAD_F(0x09bd7ca0)); x[19] = x[34] = MAD_F_MLZ(hi, lo) - t0; t12 = X[0] - X[3] + X[8] - X[11] - X[12] + X[15]; t13 = X[2] + X[5] - X[6] - X[9] - X[14] - X[17]; MAD_F_ML0(hi, lo, t12, -MAD_F(0x0ec835e8)); MAD_F_MLA(hi, lo, t13, MAD_F(0x061f78aa)); x[22] = x[31] = MAD_F_MLZ(hi, lo) + t0; MAD_F_ML0(hi, lo, X[1], -MAD_F(0x09bd7ca0)); MAD_F_MLA(hi, lo, X[7], MAD_F(0x0216a2a2)); MAD_F_MLA(hi, lo, X[10], -MAD_F(0x0fdcf549)); MAD_F_MLA(hi, lo, X[16], MAD_F(0x0cb19346)); t1 = MAD_F_MLZ(hi, lo) + t6; MAD_F_ML0(hi, lo, X[0], MAD_F(0x03768962)); MAD_F_MLA(hi, lo, X[2], MAD_F(0x0e313245)); MAD_F_MLA(hi, lo, X[3], -MAD_F(0x0ffc19fd)); MAD_F_MLA(hi, lo, X[5], -MAD_F(0x0acf37ad)); MAD_F_MLA(hi, lo, X[6], MAD_F(0x04cfb0e2)); MAD_F_MLA(hi, lo, X[8], -MAD_F(0x0898c779)); MAD_F_MLA(hi, lo, X[9], MAD_F(0x0d7e8807)); MAD_F_MLA(hi, lo, X[11], MAD_F(0x0f426cb5)); MAD_F_MLA(hi, lo, X[12], -MAD_F(0x0bcbe352)); MAD_F_MLA(hi, lo, X[14], MAD_F(0x00b2aa3e)); MAD_F_MLA(hi, lo, X[15], -MAD_F(0x07635284)); MAD_F_MLA(hi, lo, X[17], -MAD_F(0x0f9ee890)); x[6] = MAD_F_MLZ(hi, lo) + t1; x[11] = -x[6]; MAD_F_ML0(hi, lo, X[0], -MAD_F(0x0f426cb5)); MAD_F_MLA(hi, lo, X[2], -MAD_F(0x00b2aa3e)); MAD_F_MLA(hi, lo, X[3], MAD_F(0x0898c779)); MAD_F_MLA(hi, lo, X[5], MAD_F(0x0f9ee890)); MAD_F_MLA(hi, lo, X[6], MAD_F(0x0acf37ad)); MAD_F_MLA(hi, lo, X[8], -MAD_F(0x07635284)); MAD_F_MLA(hi, lo, X[9], -MAD_F(0x0e313245)); MAD_F_MLA(hi, lo, X[11], -MAD_F(0x0bcbe352)); MAD_F_MLA(hi, lo, X[12], -MAD_F(0x03768962)); MAD_F_MLA(hi, lo, X[14], MAD_F(0x0d7e8807)); MAD_F_MLA(hi, lo, X[15], MAD_F(0x0ffc19fd)); MAD_F_MLA(hi, lo, X[17], MAD_F(0x04cfb0e2)); x[23] = x[30] = MAD_F_MLZ(hi, lo) + t1; MAD_F_ML0(hi, lo, X[0], -MAD_F(0x0bcbe352)); MAD_F_MLA(hi, lo, X[2], MAD_F(0x0d7e8807)); MAD_F_MLA(hi, lo, X[3], -MAD_F(0x07635284)); MAD_F_MLA(hi, lo, X[5], MAD_F(0x04cfb0e2)); MAD_F_MLA(hi, lo, X[6], MAD_F(0x0f9ee890)); MAD_F_MLA(hi, lo, X[8], -MAD_F(0x0ffc19fd)); MAD_F_MLA(hi, lo, X[9], -MAD_F(0x00b2aa3e)); MAD_F_MLA(hi, lo, X[11], MAD_F(0x03768962)); MAD_F_MLA(hi, lo, X[12], -MAD_F(0x0f426cb5)); MAD_F_MLA(hi, lo, X[14], MAD_F(0x0e313245)); MAD_F_MLA(hi, lo, X[15], MAD_F(0x0898c779)); MAD_F_MLA(hi, lo, X[17], -MAD_F(0x0acf37ad)); x[18] = x[35] = MAD_F_MLZ(hi, lo) - t1; MAD_F_ML0(hi, lo, X[4], MAD_F(0x061f78aa)); MAD_F_MLA(hi, lo, X[13], -MAD_F(0x0ec835e8)); t7 = MAD_F_MLZ(hi, lo); MAD_F_MLA(hi, lo, X[1], -MAD_F(0x0cb19346)); MAD_F_MLA(hi, lo, X[7], MAD_F(0x0fdcf549)); MAD_F_MLA(hi, lo, X[10], MAD_F(0x0216a2a2)); MAD_F_MLA(hi, lo, X[16], -MAD_F(0x09bd7ca0)); t2 = MAD_F_MLZ(hi, lo); MAD_F_MLA(hi, lo, X[0], MAD_F(0x04cfb0e2)); MAD_F_MLA(hi, lo, X[2], MAD_F(0x0ffc19fd)); MAD_F_MLA(hi, lo, X[3], -MAD_F(0x0d7e8807)); MAD_F_MLA(hi, lo, X[5], MAD_F(0x03768962)); MAD_F_MLA(hi, lo, X[6], -MAD_F(0x0bcbe352)); MAD_F_MLA(hi, lo, X[8], -MAD_F(0x0e313245)); MAD_F_MLA(hi, lo, X[9], MAD_F(0x07635284)); MAD_F_MLA(hi, lo, X[11], -MAD_F(0x0acf37ad)); MAD_F_MLA(hi, lo, X[12], MAD_F(0x0f9ee890)); MAD_F_MLA(hi, lo, X[14], MAD_F(0x0898c779)); MAD_F_MLA(hi, lo, X[15], MAD_F(0x00b2aa3e)); MAD_F_MLA(hi, lo, X[17], MAD_F(0x0f426cb5)); x[5] = MAD_F_MLZ(hi, lo); x[12] = -x[5]; MAD_F_ML0(hi, lo, X[0], MAD_F(0x0acf37ad)); MAD_F_MLA(hi, lo, X[2], -MAD_F(0x0898c779)); MAD_F_MLA(hi, lo, X[3], MAD_F(0x0e313245)); MAD_F_MLA(hi, lo, X[5], -MAD_F(0x0f426cb5)); MAD_F_MLA(hi, lo, X[6], -MAD_F(0x03768962)); MAD_F_MLA(hi, lo, X[8], MAD_F(0x00b2aa3e)); MAD_F_MLA(hi, lo, X[9], -MAD_F(0x0ffc19fd)); MAD_F_MLA(hi, lo, X[11], MAD_F(0x0f9ee890)); MAD_F_MLA(hi, lo, X[12], -MAD_F(0x04cfb0e2)); MAD_F_MLA(hi, lo, X[14], MAD_F(0x07635284)); MAD_F_MLA(hi, lo, X[15], MAD_F(0x0d7e8807)); MAD_F_MLA(hi, lo, X[17], -MAD_F(0x0bcbe352)); x[0] = MAD_F_MLZ(hi, lo) + t2; x[17] = -x[0]; MAD_F_ML0(hi, lo, X[0], -MAD_F(0x0f9ee890)); MAD_F_MLA(hi, lo, X[2], -MAD_F(0x07635284)); MAD_F_MLA(hi, lo, X[3], -MAD_F(0x00b2aa3e)); MAD_F_MLA(hi, lo, X[5], MAD_F(0x0bcbe352)); MAD_F_MLA(hi, lo, X[6], MAD_F(0x0f426cb5)); MAD_F_MLA(hi, lo, X[8], MAD_F(0x0d7e8807)); MAD_F_MLA(hi, lo, X[9], MAD_F(0x0898c779)); MAD_F_MLA(hi, lo, X[11], -MAD_F(0x04cfb0e2)); MAD_F_MLA(hi, lo, X[12], -MAD_F(0x0acf37ad)); MAD_F_MLA(hi, lo, X[14], -MAD_F(0x0ffc19fd)); MAD_F_MLA(hi, lo, X[15], -MAD_F(0x0e313245)); MAD_F_MLA(hi, lo, X[17], -MAD_F(0x03768962)); x[24] = x[29] = MAD_F_MLZ(hi, lo) + t2; MAD_F_ML0(hi, lo, X[1], -MAD_F(0x0216a2a2)); MAD_F_MLA(hi, lo, X[7], -MAD_F(0x09bd7ca0)); MAD_F_MLA(hi, lo, X[10], MAD_F(0x0cb19346)); MAD_F_MLA(hi, lo, X[16], MAD_F(0x0fdcf549)); t3 = MAD_F_MLZ(hi, lo) + t7; MAD_F_ML0(hi, lo, X[0], MAD_F(0x00b2aa3e)); MAD_F_MLA(hi, lo, X[2], MAD_F(0x03768962)); MAD_F_MLA(hi, lo, X[3], -MAD_F(0x04cfb0e2)); MAD_F_MLA(hi, lo, X[5], -MAD_F(0x07635284)); MAD_F_MLA(hi, lo, X[6], MAD_F(0x0898c779)); MAD_F_MLA(hi, lo, X[8], MAD_F(0x0acf37ad)); MAD_F_MLA(hi, lo, X[9], -MAD_F(0x0bcbe352)); MAD_F_MLA(hi, lo, X[11], -MAD_F(0x0d7e8807)); MAD_F_MLA(hi, lo, X[12], MAD_F(0x0e313245)); MAD_F_MLA(hi, lo, X[14], MAD_F(0x0f426cb5)); MAD_F_MLA(hi, lo, X[15], -MAD_F(0x0f9ee890)); MAD_F_MLA(hi, lo, X[17], -MAD_F(0x0ffc19fd)); x[8] = MAD_F_MLZ(hi, lo) + t3; x[9] = -x[8]; MAD_F_ML0(hi, lo, X[0], -MAD_F(0x0e313245)); MAD_F_MLA(hi, lo, X[2], MAD_F(0x0bcbe352)); MAD_F_MLA(hi, lo, X[3], MAD_F(0x0f9ee890)); MAD_F_MLA(hi, lo, X[5], -MAD_F(0x0898c779)); MAD_F_MLA(hi, lo, X[6], -MAD_F(0x0ffc19fd)); MAD_F_MLA(hi, lo, X[8], MAD_F(0x04cfb0e2)); MAD_F_MLA(hi, lo, X[9], MAD_F(0x0f426cb5)); MAD_F_MLA(hi, lo, X[11], -MAD_F(0x00b2aa3e)); MAD_F_MLA(hi, lo, X[12], -MAD_F(0x0d7e8807)); MAD_F_MLA(hi, lo, X[14], -MAD_F(0x03768962)); MAD_F_MLA(hi, lo, X[15], MAD_F(0x0acf37ad)); MAD_F_MLA(hi, lo, X[17], MAD_F(0x07635284)); x[21] = x[32] = MAD_F_MLZ(hi, lo) + t3; MAD_F_ML0(hi, lo, X[0], -MAD_F(0x0d7e8807)); MAD_F_MLA(hi, lo, X[2], MAD_F(0x0f426cb5)); MAD_F_MLA(hi, lo, X[3], MAD_F(0x0acf37ad)); MAD_F_MLA(hi, lo, X[5], -MAD_F(0x0ffc19fd)); MAD_F_MLA(hi, lo, X[6], -MAD_F(0x07635284)); MAD_F_MLA(hi, lo, X[8], MAD_F(0x0f9ee890)); MAD_F_MLA(hi, lo, X[9], MAD_F(0x03768962)); MAD_F_MLA(hi, lo, X[11], -MAD_F(0x0e313245)); MAD_F_MLA(hi, lo, X[12], MAD_F(0x00b2aa3e)); MAD_F_MLA(hi, lo, X[14], MAD_F(0x0bcbe352)); MAD_F_MLA(hi, lo, X[15], -MAD_F(0x04cfb0e2)); MAD_F_MLA(hi, lo, X[17], -MAD_F(0x0898c779)); x[20] = x[33] = MAD_F_MLZ(hi, lo) - t3; MAD_F_ML0(hi, lo, t14, -MAD_F(0x0ec835e8)); MAD_F_MLA(hi, lo, t15, MAD_F(0x061f78aa)); t4 = MAD_F_MLZ(hi, lo) - t7; MAD_F_ML0(hi, lo, t12, MAD_F(0x061f78aa)); MAD_F_MLA(hi, lo, t13, MAD_F(0x0ec835e8)); x[4] = MAD_F_MLZ(hi, lo) + t4; x[13] = -x[4]; MAD_F_ML0(hi, lo, t8, MAD_F(0x09bd7ca0)); MAD_F_MLA(hi, lo, t9, -MAD_F(0x0216a2a2)); MAD_F_MLA(hi, lo, t10, MAD_F(0x0fdcf549)); MAD_F_MLA(hi, lo, t11, -MAD_F(0x0cb19346)); x[1] = MAD_F_MLZ(hi, lo) + t4; x[16] = -x[1]; MAD_F_ML0(hi, lo, t8, -MAD_F(0x0fdcf549)); MAD_F_MLA(hi, lo, t9, -MAD_F(0x0cb19346)); MAD_F_MLA(hi, lo, t10, -MAD_F(0x09bd7ca0)); MAD_F_MLA(hi, lo, t11, -MAD_F(0x0216a2a2)); x[25] = x[28] = MAD_F_MLZ(hi, lo) + t4; MAD_F_ML0(hi, lo, X[1], -MAD_F(0x0fdcf549)); MAD_F_MLA(hi, lo, X[7], -MAD_F(0x0cb19346)); MAD_F_MLA(hi, lo, X[10], -MAD_F(0x09bd7ca0)); MAD_F_MLA(hi, lo, X[16], -MAD_F(0x0216a2a2)); t5 = MAD_F_MLZ(hi, lo) - t6; MAD_F_ML0(hi, lo, X[0], MAD_F(0x0898c779)); MAD_F_MLA(hi, lo, X[2], MAD_F(0x04cfb0e2)); MAD_F_MLA(hi, lo, X[3], MAD_F(0x0bcbe352)); MAD_F_MLA(hi, lo, X[5], MAD_F(0x00b2aa3e)); MAD_F_MLA(hi, lo, X[6], MAD_F(0x0e313245)); MAD_F_MLA(hi, lo, X[8], -MAD_F(0x03768962)); MAD_F_MLA(hi, lo, X[9], MAD_F(0x0f9ee890)); MAD_F_MLA(hi, lo, X[11], -MAD_F(0x07635284)); MAD_F_MLA(hi, lo, X[12], MAD_F(0x0ffc19fd)); MAD_F_MLA(hi, lo, X[14], -MAD_F(0x0acf37ad)); MAD_F_MLA(hi, lo, X[15], MAD_F(0x0f426cb5)); MAD_F_MLA(hi, lo, X[17], -MAD_F(0x0d7e8807)); x[2] = MAD_F_MLZ(hi, lo) + t5; x[15] = -x[2]; MAD_F_ML0(hi, lo, X[0], MAD_F(0x07635284)); MAD_F_MLA(hi, lo, X[2], MAD_F(0x0acf37ad)); MAD_F_MLA(hi, lo, X[3], MAD_F(0x03768962)); MAD_F_MLA(hi, lo, X[5], MAD_F(0x0d7e8807)); MAD_F_MLA(hi, lo, X[6], -MAD_F(0x00b2aa3e)); MAD_F_MLA(hi, lo, X[8], MAD_F(0x0f426cb5)); MAD_F_MLA(hi, lo, X[9], -MAD_F(0x04cfb0e2)); MAD_F_MLA(hi, lo, X[11], MAD_F(0x0ffc19fd)); MAD_F_MLA(hi, lo, X[12], -MAD_F(0x0898c779)); MAD_F_MLA(hi, lo, X[14], MAD_F(0x0f9ee890)); MAD_F_MLA(hi, lo, X[15], -MAD_F(0x0bcbe352)); MAD_F_MLA(hi, lo, X[17], MAD_F(0x0e313245)); x[3] = MAD_F_MLZ(hi, lo) + t5; x[14] = -x[3]; MAD_F_ML0(hi, lo, X[0], -MAD_F(0x0ffc19fd)); MAD_F_MLA(hi, lo, X[2], -MAD_F(0x0f9ee890)); MAD_F_MLA(hi, lo, X[3], -MAD_F(0x0f426cb5)); MAD_F_MLA(hi, lo, X[5], -MAD_F(0x0e313245)); MAD_F_MLA(hi, lo, X[6], -MAD_F(0x0d7e8807)); MAD_F_MLA(hi, lo, X[8], -MAD_F(0x0bcbe352)); MAD_F_MLA(hi, lo, X[9], -MAD_F(0x0acf37ad)); MAD_F_MLA(hi, lo, X[11], -MAD_F(0x0898c779)); MAD_F_MLA(hi, lo, X[12], -MAD_F(0x07635284)); MAD_F_MLA(hi, lo, X[14], -MAD_F(0x04cfb0e2)); MAD_F_MLA(hi, lo, X[15], -MAD_F(0x03768962)); MAD_F_MLA(hi, lo, X[17], -MAD_F(0x00b2aa3e)); x[26] = x[27] = MAD_F_MLZ(hi, lo) + t5; } /* * NAME: III_imdct_l() * DESCRIPTION: perform IMDCT and windowing for long blocks */ static void III_imdct_l(mad_fixed_t const X[18], mad_fixed_t z[36], unsigned int block_type) { unsigned int i; /* IMDCT */ imdct36(X, z); /* windowing */ switch (block_type) { case 0: /* normal window */ # if defined(ASO_INTERLEAVE1) { register mad_fixed_t tmp1, tmp2; tmp1 = window_l[0]; tmp2 = window_l[1]; for (i = 0; i < 34; i += 2) { z[i + 0] = mad_f_mul(z[i + 0], tmp1); tmp1 = window_l[i + 2]; z[i + 1] = mad_f_mul(z[i + 1], tmp2); tmp2 = window_l[i + 3]; } z[34] = mad_f_mul(z[34], tmp1); z[35] = mad_f_mul(z[35], tmp2); } # elif defined(ASO_INTERLEAVE2) { register mad_fixed_t tmp1, tmp2; tmp1 = z[0]; tmp2 = window_l[0]; for (i = 0; i < 35; ++i) { z[i] = mad_f_mul(tmp1, tmp2); tmp1 = z[i + 1]; tmp2 = window_l[i + 1]; } z[35] = mad_f_mul(tmp1, tmp2); } # elif 1 for (i = 0; i < 36; i += 4) { z[i + 0] = mad_f_mul(z[i + 0], window_l[i + 0]); z[i + 1] = mad_f_mul(z[i + 1], window_l[i + 1]); z[i + 2] = mad_f_mul(z[i + 2], window_l[i + 2]); z[i + 3] = mad_f_mul(z[i + 3], window_l[i + 3]); } # else for (i = 0; i < 36; ++i) z[i] = mad_f_mul(z[i], window_l[i]); # endif break; case 1: /* start block */ for (i = 0; i < 18; ++i) z[i] = mad_f_mul(z[i], window_l[i]); /* (i = 18; i < 24; ++i) z[i] unchanged */ for (i = 24; i < 30; ++i) z[i] = mad_f_mul(z[i], window_s[i - 18]); for (i = 30; i < 36; ++i) z[i] = 0; break; case 3: /* stop block */ for (i = 0; i < 6; ++i) z[i] = 0; for (i = 6; i < 12; ++i) z[i] = mad_f_mul(z[i], window_s[i - 6]); /* (i = 12; i < 18; ++i) z[i] unchanged */ for (i = 18; i < 36; ++i) z[i] = mad_f_mul(z[i], window_l[i]); break; } } # endif /* ASO_IMDCT */ /* * NAME: III_imdct_s() * DESCRIPTION: perform IMDCT and windowing for short blocks */ static void III_imdct_s(mad_fixed_t const X[18], mad_fixed_t z[36]) { mad_fixed_t y[36], *yptr; mad_fixed_t const *wptr; int w, i; register mad_fixed64hi_t hi; register mad_fixed64lo_t lo; /* IMDCT */ yptr = &y[0]; for (w = 0; w < 3; ++w) { register mad_fixed_t const (*s)[6]; s = imdct_s; for (i = 0; i < 3; ++i) { MAD_F_ML0(hi, lo, X[0], (*s)[0]); MAD_F_MLA(hi, lo, X[1], (*s)[1]); MAD_F_MLA(hi, lo, X[2], (*s)[2]); MAD_F_MLA(hi, lo, X[3], (*s)[3]); MAD_F_MLA(hi, lo, X[4], (*s)[4]); MAD_F_MLA(hi, lo, X[5], (*s)[5]); yptr[i + 0] = MAD_F_MLZ(hi, lo); yptr[5 - i] = -yptr[i + 0]; ++s; MAD_F_ML0(hi, lo, X[0], (*s)[0]); MAD_F_MLA(hi, lo, X[1], (*s)[1]); MAD_F_MLA(hi, lo, X[2], (*s)[2]); MAD_F_MLA(hi, lo, X[3], (*s)[3]); MAD_F_MLA(hi, lo, X[4], (*s)[4]); MAD_F_MLA(hi, lo, X[5], (*s)[5]); yptr[ i + 6] = MAD_F_MLZ(hi, lo); yptr[11 - i] = yptr[i + 6]; ++s; } yptr += 12; X += 6; } /* windowing, overlapping and concatenation */ yptr = &y[0]; wptr = &window_s[0]; for (i = 0; i < 6; ++i) { z[i + 0] = 0; z[i + 6] = mad_f_mul(yptr[ 0 + 0], wptr[0]); MAD_F_ML0(hi, lo, yptr[ 0 + 6], wptr[6]); MAD_F_MLA(hi, lo, yptr[12 + 0], wptr[0]); z[i + 12] = MAD_F_MLZ(hi, lo); MAD_F_ML0(hi, lo, yptr[12 + 6], wptr[6]); MAD_F_MLA(hi, lo, yptr[24 + 0], wptr[0]); z[i + 18] = MAD_F_MLZ(hi, lo); z[i + 24] = mad_f_mul(yptr[24 + 6], wptr[6]); z[i + 30] = 0; ++yptr; ++wptr; } } /* * NAME: III_overlap() * DESCRIPTION: perform overlap-add of windowed IMDCT outputs */ static void III_overlap(mad_fixed_t const output[36], mad_fixed_t overlap[18], mad_fixed_t sample[18][32], unsigned int sb) { unsigned int i; # if defined(ASO_INTERLEAVE2) { register mad_fixed_t tmp1, tmp2; tmp1 = overlap[0]; tmp2 = overlap[1]; for (i = 0; i < 16; i += 2) { sample[i + 0][sb] = output[i + 0] + tmp1; overlap[i + 0] = output[i + 0 + 18]; tmp1 = overlap[i + 2]; sample[i + 1][sb] = output[i + 1] + tmp2; overlap[i + 1] = output[i + 1 + 18]; tmp2 = overlap[i + 3]; } sample[16][sb] = output[16] + tmp1; overlap[16] = output[16 + 18]; sample[17][sb] = output[17] + tmp2; overlap[17] = output[17 + 18]; } # elif 0 for (i = 0; i < 18; i += 2) { sample[i + 0][sb] = output[i + 0] + overlap[i + 0]; overlap[i + 0] = output[i + 0 + 18]; sample[i + 1][sb] = output[i + 1] + overlap[i + 1]; overlap[i + 1] = output[i + 1 + 18]; } # else for (i = 0; i < 18; ++i) { sample[i][sb] = output[i] + overlap[i]; overlap[i] = output[i + 18]; } # endif } /* * NAME: III_overlap_z() * DESCRIPTION: perform "overlap-add" of zero IMDCT outputs */ static inline void III_overlap_z(mad_fixed_t overlap[18], mad_fixed_t sample[18][32], unsigned int sb) { unsigned int i; # if defined(ASO_INTERLEAVE2) { register mad_fixed_t tmp1, tmp2; tmp1 = overlap[0]; tmp2 = overlap[1]; for (i = 0; i < 16; i += 2) { sample[i + 0][sb] = tmp1; overlap[i + 0] = 0; tmp1 = overlap[i + 2]; sample[i + 1][sb] = tmp2; overlap[i + 1] = 0; tmp2 = overlap[i + 3]; } sample[16][sb] = tmp1; overlap[16] = 0; sample[17][sb] = tmp2; overlap[17] = 0; } # else for (i = 0; i < 18; ++i) { sample[i][sb] = overlap[i]; overlap[i] = 0; } # endif } /* * NAME: III_freqinver() * DESCRIPTION: perform subband frequency inversion for odd sample lines */ static void III_freqinver(mad_fixed_t sample[18][32], unsigned int sb) { unsigned int i; # if 1 || defined(ASO_INTERLEAVE1) || defined(ASO_INTERLEAVE2) { register mad_fixed_t tmp1, tmp2; tmp1 = sample[1][sb]; tmp2 = sample[3][sb]; for (i = 1; i < 13; i += 4) { sample[i + 0][sb] = -tmp1; tmp1 = sample[i + 4][sb]; sample[i + 2][sb] = -tmp2; tmp2 = sample[i + 6][sb]; } sample[13][sb] = -tmp1; tmp1 = sample[17][sb]; sample[15][sb] = -tmp2; sample[17][sb] = -tmp1; } # else for (i = 1; i < 18; i += 2) sample[i][sb] = -sample[i][sb]; # endif } /* * NAME: III_decode() * DESCRIPTION: decode frame main_data */ static int III_decode(struct mad_bitptr *ptr, struct mad_frame *frame, struct sideinfo *si, unsigned int nch) { struct mad_header *header = &frame->header; unsigned int sfreqi, ngr, gr; { unsigned int sfreq; sfreq = header->samplerate; if (header->flags & MAD_FLAG_MPEG_2_5_EXT) sfreq *= 2; /* 48000 => 0, 44100 => 1, 32000 => 2, 24000 => 3, 22050 => 4, 16000 => 5 */ sfreqi = ((sfreq >> 7) & 0x000f) + ((sfreq >> 15) & 0x0001) - 8; if (header->flags & MAD_FLAG_MPEG_2_5_EXT) sfreqi += 3; } /* scalefactors, Huffman decoding, requantization */ ngr = (header->flags & MAD_FLAG_LSF_EXT) ? 1 : 2; for (gr = 0; gr < ngr; ++gr) { struct granule *granule = &si->gr[gr]; unsigned char const *sfbwidth = 0; mad_fixed_t xr[2][576]; unsigned int ch; enum mad_error error; for (ch = 0; ch < nch; ++ch) { struct channel *channel = &granule->ch[ch]; unsigned int part2_length; sfbwidth = sfbwidth_table[sfreqi].l; if (channel->block_type == 2) { sfbwidth = (channel->flags & mixed_block_flag) ? sfbwidth_table[sfreqi].m : sfbwidth_table[sfreqi].s; } if (header->flags & MAD_FLAG_LSF_EXT) { part2_length = III_scalefactors_lsf(ptr, channel, ch == 0 ? 0 : &si->gr[1].ch[1], header->mode_extension); } else { part2_length = III_scalefactors(ptr, channel, &si->gr[0].ch[ch], gr == 0 ? 0 : si->scfsi[ch]); } error = III_huffdecode(ptr, xr[ch], channel, sfbwidth, part2_length); if (error) return error; } /* joint stereo processing */ if (header->mode == MAD_MODE_JOINT_STEREO && header->mode_extension) { error = III_stereo(xr, granule, header, sfbwidth); if (error) return error; } /* reordering, alias reduction, IMDCT, overlap-add, frequency inversion */ for (ch = 0; ch < nch; ++ch) { struct channel const *channel = &granule->ch[ch]; mad_fixed_t (*sample)[32] = &frame->sbsample[ch][18 * gr]; unsigned int sb, l, i, sblimit; mad_fixed_t output[36]; if (channel->block_type == 2) { III_reorder(xr[ch], channel, sfbwidth_table[sfreqi].s); # if !defined(OPT_STRICT) /* * According to ISO/IEC 11172-3, "Alias reduction is not applied for * granules with block_type == 2 (short block)." However, other * sources suggest alias reduction should indeed be performed on the * lower two subbands of mixed blocks. Most other implementations do * this, so by default we will too. */ if (channel->flags & mixed_block_flag) III_aliasreduce(xr[ch], 36); # endif } else III_aliasreduce(xr[ch], 576); l = 0; /* subbands 0-1 */ if (channel->block_type != 2 || (channel->flags & mixed_block_flag)) { unsigned int block_type; block_type = channel->block_type; if (channel->flags & mixed_block_flag) block_type = 0; /* long blocks */ for (sb = 0; sb < 2; ++sb, l += 18) { III_imdct_l(&xr[ch][l], output, block_type); III_overlap(output, (*frame->overlap)[ch][sb], sample, sb); } } else { /* short blocks */ for (sb = 0; sb < 2; ++sb, l += 18) { III_imdct_s(&xr[ch][l], output); III_overlap(output, (*frame->overlap)[ch][sb], sample, sb); } } III_freqinver(sample, 1); /* (nonzero) subbands 2-31 */ i = 576; while (i > 36 && xr[ch][i - 1] == 0) --i; sblimit = 32 - (576 - i) / 18; if (channel->block_type != 2) { /* long blocks */ for (sb = 2; sb < sblimit; ++sb, l += 18) { III_imdct_l(&xr[ch][l], output, channel->block_type); III_overlap(output, (*frame->overlap)[ch][sb], sample, sb); if (sb & 1) III_freqinver(sample, sb); } } else { /* short blocks */ for (sb = 2; sb < sblimit; ++sb, l += 18) { III_imdct_s(&xr[ch][l], output); III_overlap(output, (*frame->overlap)[ch][sb], sample, sb); if (sb & 1) III_freqinver(sample, sb); } } /* remaining (zero) subbands */ for (sb = sblimit; sb < 32; ++sb) { III_overlap_z((*frame->overlap)[ch][sb], sample, sb); if (sb & 1) III_freqinver(sample, sb); } } } return 0; } unsigned char g_main_data[MAD_BUFFER_MDLEN]; mad_fixed_t g_frame_overlap [2][32][18]; /* * NAME: layer->III() * DESCRIPTION: decode a single Layer III frame */ int mad_layer_III(struct mad_stream *stream, struct mad_frame *frame) { struct mad_header *header = &frame->header; unsigned int nch, priv_bitlen, next_md_begin = 0; unsigned int si_len, data_bitlen, md_len; unsigned int frame_space, frame_used, frame_free; struct mad_bitptr ptr; struct sideinfo si; enum mad_error error; int result = 0; /* allocate Layer III dynamic structures */ if (!stream->main_data) stream->main_data = (unsigned char *)stream->buffer; //&g_main_data; frame->overlap = &g_frame_overlap; nch = MAD_NCHANNELS(header); si_len = (header->flags & MAD_FLAG_LSF_EXT) ? (nch == 1 ? 9 : 17) : (nch == 1 ? 17 : 32); /* check frame sanity */ if (stream->next_frame - mad_bit_nextbyte(&stream->ptr) < (signed int) si_len) { stream->error = MAD_ERROR_BADFRAMELEN; stream->md_len = 0; return -1; } /* check CRC word */ if (header->flags & MAD_FLAG_PROTECTION) { header->crc_check = mad_bit_crc(stream->ptr, si_len * CHAR_BIT, header->crc_check); if (header->crc_check != header->crc_target && !(frame->options & MAD_OPTION_IGNORECRC)) { stream->error = MAD_ERROR_BADCRC; result = -1; } } /* decode frame side information */ error = III_sideinfo(&stream->ptr, nch, header->flags & MAD_FLAG_LSF_EXT, &si, &data_bitlen, &priv_bitlen); if (error && result == 0) { stream->error = error; result = -1; } header->flags |= priv_bitlen; header->private_bits |= si.private_bits; /* find main_data of next frame */ { struct mad_bitptr peek; unsigned long header; mad_bit_init(&peek, stream->next_frame); header = mad_bit_read(&peek, 32); if ((header & 0xffe60000L) /* syncword | layer */ == 0xffe20000L) { if (!(header & 0x00010000L)) /* protection_bit */ mad_bit_skip(&peek, 16); /* crc_check */ next_md_begin = mad_bit_read(&peek, (header & 0x00080000L) /* ID */ ? 9 : 8); } mad_bit_finish(&peek); } /* find main_data of this frame */ frame_space = stream->next_frame - mad_bit_nextbyte(&stream->ptr); if (next_md_begin > si.main_data_begin + frame_space) next_md_begin = 0; md_len = si.main_data_begin + frame_space - next_md_begin; frame_used = 0; if (si.main_data_begin == 0) { ptr = stream->ptr; stream->md_len = 0; frame_used = md_len; } else { if (si.main_data_begin > stream->md_len) { if (result == 0) { stream->error = MAD_ERROR_BADDATAPTR; result = -1; } } else { mad_bit_init(&ptr, stream->main_data + stream->md_len - si.main_data_begin); if (md_len > si.main_data_begin) { assert(stream->md_len + md_len - si.main_data_begin <= MAD_BUFFER_MDLEN); memcpy(stream->main_data + stream->md_len, mad_bit_nextbyte(&stream->ptr), frame_used = md_len - si.main_data_begin); stream->md_len += frame_used; } } } frame_free = frame_space - frame_used; /* decode main_data */ if (result == 0) { error = III_decode(&ptr, frame, &si, nch); if (error) { stream->error = error; result = -1; } } /* designate ancillary bits */ stream->anc_ptr = ptr; stream->anc_bitlen = md_len * CHAR_BIT - data_bitlen; /* fprintf(stderr, "main_data_begin:%u, md_len:%u, frame_free:%u, " "data_bitlen:%u, anc_bitlen: %u\n", si.main_data_begin, md_len, frame_free, data_bitlen, stream->anc_bitlen);*/ /* preload main_data buffer with up to 511 bytes for next frame(s) */ if (frame_free >= next_md_begin) { memcpy(stream->main_data, stream->next_frame - next_md_begin, next_md_begin); stream->md_len = next_md_begin; } else { if (md_len < si.main_data_begin) { unsigned int extra; extra = si.main_data_begin - md_len; if (extra + frame_free > next_md_begin) extra = next_md_begin - frame_free; if (extra < stream->md_len) { memmove(stream->main_data, stream->main_data + stream->md_len - extra, extra); stream->md_len = extra; } } else stream->md_len = 0; memcpy(stream->main_data + stream->md_len, stream->next_frame - frame_free, frame_free); stream->md_len += frame_free; } return result; }
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