#pragma warning(disable:4206) // nonstandard extension used : translation unit is empty #ifdef COMPILE_ME /*____________________________________________________________________________ FreeAmp - The Free MP3 Player MP3 Decoder originally Copyright (C) 1995-1997 Xing Technology Corp. http://www.xingtech.com Portions Copyright (C) 1998-1999 EMusic.com 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., 675 Mass Ave, Cambridge, MA 02139, USA. $Id: cupini.c,v 1.3 1999/10/19 07:13:08 elrod Exp $ ____________________________________________________________________________*/ /*========================================================= initialization for cup.c - include to cup.c mpeg audio decoder portable "c" mod 8/6/96 add 8 bit output mod 5/10/95 add quick (low precision) window mod 5/16/95 sb limit for reduced samprate output changed from 94% to 100% of Nyquist sb mod 11/15/95 for Layer I =========================================================*/ /*-- compiler bug, floating constant overflow w/ansi --*/ #ifdef _MSC_VER #pragma warning(disable:4056) #endif static const long steps[18] = { 0, 3, 5, 7, 9, 15, 31, 63, 127, 255, 511, 1023, 2047, 4095, 8191, 16383, 32767, 65535}; /* ABCD_INDEX = lookqt[mode][sr_index][br_index] */ /* -1 = invalid */ static const signed char lookqt[4][3][16] = { {{1, -1, -1, -1, 2, -1, 2, 0, 0, 0, 1, 1, 1, 1, 1, -1}, /* 44ks stereo */ {0, -1, -1, -1, 2, -1, 2, 0, 0, 0, 0, 0, 0, 0, 0, -1}, /* 48ks */ {1, -1, -1, -1, 3, -1, 3, 0, 0, 0, 1, 1, 1, 1, 1, -1}}, /* 32ks */ {{1, -1, -1, -1, 2, -1, 2, 0, 0, 0, 1, 1, 1, 1, 1, -1}, /* 44ks joint stereo */ {0, -1, -1, -1, 2, -1, 2, 0, 0, 0, 0, 0, 0, 0, 0, -1}, /* 48ks */ {1, -1, -1, -1, 3, -1, 3, 0, 0, 0, 1, 1, 1, 1, 1, -1}}, /* 32ks */ {{1, -1, -1, -1, 2, -1, 2, 0, 0, 0, 1, 1, 1, 1, 1, -1}, /* 44ks dual chan */ {0, -1, -1, -1, 2, -1, 2, 0, 0, 0, 0, 0, 0, 0, 0, -1}, /* 48ks */ {1, -1, -1, -1, 3, -1, 3, 0, 0, 0, 1, 1, 1, 1, 1, -1}}, /* 32ks */ // mono extended beyond legal br index // 1,2,2,0,0,0,1,1,1,1,1,1,1,1,1,-1, /* 44ks single chan */ // 0,2,2,0,0,0,0,0,0,0,0,0,0,0,0,-1, /* 48ks */ // 1,3,3,0,0,0,1,1,1,1,1,1,1,1,1,-1, /* 32ks */ // legal mono {{1, 2, 2, 0, 0, 0, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1}, /* 44ks single chan */ {0, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, -1, -1, -1, -1, -1}, /* 48ks */ {1, 3, 3, 0, 0, 0, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1}}, /* 32ks */ }; static const long sr_table[8] = {22050L, 24000L, 16000L, 1L, 44100L, 48000L, 32000L, 1L}; /* bit allocation table look up */ /* table per mpeg spec tables 3b2a/b/c/d /e is mpeg2 */ /* look_bat[abcd_index][4][16] */ static const unsigned char look_bat[5][4][16] = { /* LOOK_BATA */ {{0, 1, 3, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17}, {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 17}, {0, 1, 2, 3, 4, 5, 6, 17, 0, 0, 0, 0, 0, 0, 0, 0}, {0, 1, 2, 17, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}}, /* LOOK_BATB */ {{0, 1, 3, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17}, {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 17}, {0, 1, 2, 3, 4, 5, 6, 17, 0, 0, 0, 0, 0, 0, 0, 0}, {0, 1, 2, 17, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}}, /* LOOK_BATC */ {{0, 1, 2, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16}, {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, {0, 1, 2, 4, 5, 6, 7, 8, 0, 0, 0, 0, 0, 0, 0, 0}, {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}}, /* LOOK_BATD */ {{0, 1, 2, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16}, {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, {0, 1, 2, 4, 5, 6, 7, 8, 0, 0, 0, 0, 0, 0, 0, 0}, {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}}, /* LOOK_BATE */ {{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}, {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, {0, 1, 2, 4, 5, 6, 7, 8, 0, 0, 0, 0, 0, 0, 0, 0}, {0, 1, 2, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}}, }; /* look_nbat[abcd_index]][4] */ static const unsigned char look_nbat[5][4] = { {3, 8, 12, 4}, {3, 8, 12, 7}, {2, 0, 6, 0}, {2, 0, 10, 0}, {4, 0, 7, 19}, }; void sbt_mono(float *sample, short *pcm, int n); void sbt_dual(float *sample, short *pcm, int n); void sbt_dual_mono(float *sample, short *pcm, int n); void sbt_dual_left(float *sample, short *pcm, int n); void sbt_dual_right(float *sample, short *pcm, int n); void sbt16_mono(float *sample, short *pcm, int n); void sbt16_dual(float *sample, short *pcm, int n); void sbt16_dual_mono(float *sample, short *pcm, int n); void sbt16_dual_left(float *sample, short *pcm, int n); void sbt16_dual_right(float *sample, short *pcm, int n); void sbt8_mono(float *sample, short *pcm, int n); void sbt8_dual(float *sample, short *pcm, int n); void sbt8_dual_mono(float *sample, short *pcm, int n); void sbt8_dual_left(float *sample, short *pcm, int n); void sbt8_dual_right(float *sample, short *pcm, int n); /*--- 8 bit output ---*/ void sbtB_mono(float *sample, unsigned char *pcm, int n); void sbtB_dual(float *sample, unsigned char *pcm, int n); void sbtB_dual_mono(float *sample, unsigned char *pcm, int n); void sbtB_dual_left(float *sample, unsigned char *pcm, int n); void sbtB_dual_right(float *sample, unsigned char *pcm, int n); void sbtB16_mono(float *sample, unsigned char *pcm, int n); void sbtB16_dual(float *sample, unsigned char *pcm, int n); void sbtB16_dual_mono(float *sample, unsigned char *pcm, int n); void sbtB16_dual_left(float *sample, unsigned char *pcm, int n); void sbtB16_dual_right(float *sample, unsigned char *pcm, int n); void sbtB8_mono(float *sample, unsigned char *pcm, int n); void sbtB8_dual(float *sample, unsigned char *pcm, int n); void sbtB8_dual_mono(float *sample, unsigned char *pcm, int n); void sbtB8_dual_left(float *sample, unsigned char *pcm, int n); void sbtB8_dual_right(float *sample, unsigned char *pcm, int n); static const SBT_FUNCTION sbt_table[2][3][5] = { {{sbt_mono, sbt_dual, sbt_dual_mono, sbt_dual_left, sbt_dual_right}, {sbt16_mono, sbt16_dual, sbt16_dual_mono, sbt16_dual_left, sbt16_dual_right}, {sbt8_mono, sbt8_dual, sbt8_dual_mono, sbt8_dual_left, sbt8_dual_right}}, {{(SBT_FUNCTION) sbtB_mono, (SBT_FUNCTION) sbtB_dual, (SBT_FUNCTION) sbtB_dual_mono, (SBT_FUNCTION) sbtB_dual_left, (SBT_FUNCTION) sbtB_dual_right}, {(SBT_FUNCTION) sbtB16_mono, (SBT_FUNCTION) sbtB16_dual, (SBT_FUNCTION) sbtB16_dual_mono, (SBT_FUNCTION) sbtB16_dual_left, (SBT_FUNCTION) sbtB16_dual_right}, {(SBT_FUNCTION) sbtB8_mono, (SBT_FUNCTION) sbtB8_dual, (SBT_FUNCTION) sbtB8_dual_mono, (SBT_FUNCTION) sbtB8_dual_left, (SBT_FUNCTION) sbtB8_dual_right}}, }; static const int out_chans[5] = {1, 2, 1, 1, 1}; int audio_decode_initL1(MPEG_HEAD * h, int framebytes_arg, int reduction_code, int transform_code, int convert_code, int freq_limit); void sbt_init(); IN_OUT L1audio_decode(unsigned char *bs, signed short *pcm); IN_OUT L2audio_decode(unsigned char *bs, signed short *pcm); IN_OUT L3audio_decode(unsigned char *bs, unsigned char *pcm); static const AUDIO_DECODE_ROUTINE decode_routine_table[4] = { L2audio_decode, (AUDIO_DECODE_ROUTINE)L3audio_decode, L2audio_decode, L1audio_decode,}; /*---------------------------------------------------------*/ static void table_init() { int i, j; int code; static int iOnceOnly=0; if (!iOnceOnly++) { /*-- c_values (dequant) --*/ for (i = 1; i < 18; i++) look_c_value[i] = 2.0F / steps[i]; /*-- scale factor table, scale by 32768 for 16 pcm output --*/ for (i = 0; i < 64; i++) sf_table[i] = (float) (32768.0 * 2.0 * pow(2.0, -i / 3.0)); /*-- grouped 3 level lookup table 5 bit token --*/ for (i = 0; i < 32; i++) { code = i; for (j = 0; j < 3; j++) { group3_table[i][j] = (char) ((code % 3) - 1); code /= 3; } } /*-- grouped 5 level lookup table 7 bit token --*/ for (i = 0; i < 128; i++) { code = i; for (j = 0; j < 3; j++) { group5_table[i][j] = (char) ((code % 5) - 2); code /= 5; } } /*-- grouped 9 level lookup table 10 bit token --*/ for (i = 0; i < 1024; i++) { code = i; for (j = 0; j < 3; j++) { group9_table[i][j] = (short) ((code % 9) - 4); code /= 9; } } } } /*---------------------------------------------------------*/ int L1audio_decode_init(MPEG_HEAD * h, int framebytes_arg, int reduction_code, int transform_code, int convert_code, int freq_limit); int L3audio_decode_init(MPEG_HEAD * h, int framebytes_arg, int reduction_code, int transform_code, int convert_code, int freq_limit); /*---------------------------------------------------------*/ /* mpeg_head defined in mhead.h frame bytes is without pad */ int audio_decode_init(MPEG_HEAD * h, int framebytes_arg, int reduction_code, int transform_code, int convert_code, int freq_limit) { int i, j, k; static int first_pass = 1; int abcd_index; long samprate; int limit; int bit_code; if (first_pass) { table_init(); first_pass = 0; } /* select decoder routine Layer I,II,III */ audio_decode_routine = decode_routine_table[h->option & 3]; if (h->option == 3) /* layer I */ return L1audio_decode_init(h, framebytes_arg, reduction_code, transform_code, convert_code, freq_limit); if (h->option == 1) /* layer III */ return L3audio_decode_init(h, framebytes_arg, reduction_code, transform_code, convert_code, freq_limit); transform_code = transform_code; /* not used, asm compatability */ bit_code = 0; if (convert_code & 8) bit_code = 1; convert_code = convert_code & 3; /* higher bits used by dec8 freq cvt */ if (reduction_code < 0) reduction_code = 0; if (reduction_code > 2) reduction_code = 2; if (freq_limit < 1000) freq_limit = 1000; pMP3Stream->framebytes = framebytes_arg; /* check if code handles */ if (h->option != 2) return 0; /* layer II only */ if (h->sr_index == 3) return 0; /* reserved */ /* compute abcd index for bit allo table selection */ if (h->id) /* mpeg 1 */ abcd_index = lookqt[h->mode][h->sr_index][h->br_index]; else abcd_index = 4; /* mpeg 2 */ if (abcd_index < 0) return 0; // fail invalid Layer II bit rate index for (i = 0; i < 4; i++) for (j = 0; j < 16; j++) pMP3Stream->bat[i][j] = look_bat[abcd_index][i][j]; for (i = 0; i < 4; i++) pMP3Stream->nbat[i] = look_nbat[abcd_index][i]; pMP3Stream->max_sb = pMP3Stream->nbat[0] + pMP3Stream->nbat[1] + pMP3Stream->nbat[2] + pMP3Stream->nbat[3]; /*----- compute pMP3Stream->nsb_limit --------*/ samprate = sr_table[4 * h->id + h->sr_index]; pMP3Stream->nsb_limit = (freq_limit * 64L + samprate / 2) / samprate; /*- caller limit -*/ /*---- limit = 0.94*(32>>reduction_code); ----*/ limit = (32 >> reduction_code); if (limit > 8) limit--; if (pMP3Stream->nsb_limit > limit) pMP3Stream->nsb_limit = limit; if (pMP3Stream->nsb_limit > pMP3Stream->max_sb) pMP3Stream->nsb_limit = pMP3Stream->max_sb; pMP3Stream->outvalues = 1152 >> reduction_code; if (h->mode != 3) { /* adjust for 2 channel modes */ for (i = 0; i < 4; i++) pMP3Stream->nbat[i] *= 2; pMP3Stream->max_sb *= 2; pMP3Stream->nsb_limit *= 2; } /* set sbt function */ k = 1 + convert_code; if (h->mode == 3) { k = 0; } pMP3Stream->sbt = sbt_table[bit_code][reduction_code][k]; pMP3Stream->outvalues *= out_chans[k]; if (bit_code) pMP3Stream->outbytes = pMP3Stream->outvalues; else pMP3Stream->outbytes = sizeof(short) * pMP3Stream->outvalues; decinfo.channels = out_chans[k]; decinfo.outvalues = pMP3Stream->outvalues; decinfo.samprate = samprate >> reduction_code; if (bit_code) decinfo.bits = 8; else decinfo.bits = sizeof(short) * 8; decinfo.framebytes = pMP3Stream->framebytes; decinfo.type = 0; /* clear sample buffer, unused sub bands must be 0 */ for (i = 0; i < 2304*2; i++) // the *2 here was inserted by me just in case, since the array is now *2, because of stereo files unpacking at 4608 bytes per frame (which may or may not be relevant, but in any case I don't think we use the L1 versions of MP3 now anyway sample[i] = 0.0F; /* init sub-band transform */ sbt_init(); return 1; } /*---------------------------------------------------------*/ void audio_decode_info(DEC_INFO * info) { *info = decinfo; /* info return, call after init */ } /*---------------------------------------------------------*/ void decode_table_init() { /* dummy for asm version compatability */ } /*---------------------------------------------------------*/ #endif // #ifdef COMPILE_ME