diff options
Diffstat (limited to 'codecs/mp3/src/cup.c')
-rwxr-xr-x | codecs/mp3/src/cup.c | 500 |
1 files changed, 500 insertions, 0 deletions
diff --git a/codecs/mp3/src/cup.c b/codecs/mp3/src/cup.c new file mode 100755 index 000000000..34659f15b --- /dev/null +++ b/codecs/mp3/src/cup.c @@ -0,0 +1,500 @@ +/*____________________________________________________________________________ + + 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. + + $Id$ +____________________________________________________________________________*/ + +/**** cup.c *************************************************** + +MPEG audio decoder Layer I/II mpeg1 and mpeg2 +should be portable ANSI C, should be endian independent + + +mod 2/21/95 2/21/95 add bit skip, sb limiting + +mods 11/15/95 for Layer I + +******************************************************************/ +/****************************************************************** + + MPEG audio software decoder portable ANSI c. + Decodes all Layer I/II to 16 bit linear pcm. + Optional stereo to mono conversion. Optional + output sample rate conversion to half or quarter of + native mpeg rate. dec8.c adds oupuut conversion features. + +------------------------------------- +int audio_decode_init(MPEG *m, MPEG_HEAD *h, int framebytes_arg, + int reduction_code, int transform_code, int convert_code, + int freq_limit) + +initilize decoder: + return 0 = fail, not 0 = success + +MPEG *m input, mpeg structure for multiple streams +MPEG_HEAD *h input, mpeg header info (returned by call to head_info) +framebytes input, mpeg frame size (returned by call to head_info) +reduction_code input, sample rate reduction code + 0 = full rate + 1 = half rate + 2 = quarter rate + +transform_code input, ignored +convert_code input, channel conversion + convert_code: 0 = two chan output + 1 = convert two chan to mono + 2 = convert two chan to left chan + 3 = convert two chan to right chan +freq_limit input, limits bandwidth of pcm output to specified + frequency. Special use. Set to 24000 for normal use. + + +--------------------------------- +void audio_decode_info( MPEG *m, DEC_INFO *info) + +MPEG *m input, mpeg structure for multiple streams +information return: + Call after audio_decode_init. See mhead.h for + information returned in DEC_INFO structure. + + +--------------------------------- +IN_OUT audio_decode(unsigned char *bs, void *pcmbuf) + +decode one mpeg audio frame: +bs input, mpeg bitstream, must start with + sync word. Caution: may read up to 3 bytes + beyond end of frame. +pcmbuf output, pcm samples. + +IN_OUT structure returns: + Number bytes conceptually removed from mpeg bitstream. + Returns 0 if sync loss. + Number bytes of pcm output. + +*******************************************************************/ + + +#include <stdlib.h> +#include <stdio.h> +#include <float.h> +#include <math.h> +#include "L3.h" +#include "mhead.h" /* mpeg header structure */ + + +#ifdef _MSC_VER +#pragma warning(disable: 4709) +#endif + + +/*------------------------------------------------------- +NOTE: Decoder may read up to three bytes beyond end of +frame. Calling application must ensure that this does +not cause a memory access violation (protection fault) +---------------------------------------------------------*/ + +/*====================================================================*/ +/*----------------*/ + +/* Read Only */ +static int look_joint[16] = +{ /* lookup stereo sb's by mode+ext */ + 64, 64, 64, 64, /* stereo */ + 2 * 4, 2 * 8, 2 * 12, 2 * 16, /* joint */ + 64, 64, 64, 64, /* dual */ + 32, 32, 32, 32, /* mono */ +}; /* Okay to be global */ + +/* Read Only */ +static int bat_bit_master[] = +{ + 0, 5, 7, 9, 10, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, 45, 48}; + + +void sbt_mono(MPEG *m, float *sample, short *pcm, int n); +void sbt_dual(MPEG *m, float *sample, short *pcm, int n); + + +IN_OUT L2audio_decode(void *mv, unsigned char *bs, signed short *pcm); + +/*======================================================================*/ +/*======================================================================*/ + +/*------------- initialize bit getter -------------*/ +static void load_init(MPEG *m, unsigned char *buf) +{ + m->cup.bs_ptr = buf; + m->cup.bits = 0; + m->cup.bitbuf = 0; +} +/*------------- get n bits from bitstream -------------*/ +static long load(MPEG *m, int n) +{ + unsigned long x; + + if (m->cup.bits < n) + { /* refill bit buf if necessary */ + while (m->cup.bits <= 24) + { + m->cup.bitbuf = (m->cup.bitbuf << 8) | *m->cup.bs_ptr++; + m->cup.bits += 8; + } + } + m->cup.bits -= n; + x = m->cup.bitbuf >> m->cup.bits; + m->cup.bitbuf -= x << m->cup.bits; + return x; +} +/*------------- skip over n bits in bitstream -------------*/ +static void skip(MPEG *m, int n) +{ + int k; + + if (m->cup.bits < n) + { + n -= m->cup.bits; + k = n >> 3; +/*--- bytes = n/8 --*/ + m->cup.bs_ptr += k; + n -= k << 3; + m->cup.bitbuf = *m->cup.bs_ptr++; + m->cup.bits = 8; + } + m->cup.bits -= n; + m->cup.bitbuf -= (m->cup.bitbuf >> m->cup.bits) << m->cup.bits; +} +/*--------------------------------------------------------------*/ +#define mac_load_check(n) if( m->cup.bits < (n) ) { \ + while( m->cup.bits <= 24 ) { \ + m->cup.bitbuf = (m->cup.bitbuf << 8) | *m->cup.bs_ptr++; \ + m->cup.bits += 8; \ + } \ + } +/*--------------------------------------------------------------*/ +#define mac_load(n) ( m->cup.bits -= n, \ + m->cup.bitval = m->cup.bitbuf >> m->cup.bits, \ + m->cup.bitbuf -= m->cup.bitval << m->cup.bits, \ + m->cup.bitval ) +/*======================================================================*/ +static void unpack_ba(MPEG *m) +{ + int i, j, k; + /* Read Only */ + static int nbit[4] = + {4, 4, 3, 2}; + int nstereo; + + m->cup.bit_skip = 0; + nstereo = m->cup.stereo_sb; + k = 0; + for (i = 0; i < 4; i++) + { + for (j = 0; j < m->cup.nbat[i]; j++, k++) + { + mac_load_check(4); + m->cup.ballo[k] = m->cup.samp_dispatch[k] = m->cup.bat[i][mac_load(nbit[i])]; + if (k >= m->cup.nsb_limit) + m->cup.bit_skip += bat_bit_master[m->cup.samp_dispatch[k]]; + m->cup.c_value[k] = m->cup.look_c_value[m->cup.samp_dispatch[k]]; + if (--nstereo < 0) + { + m->cup.ballo[k + 1] = m->cup.ballo[k]; + m->cup.samp_dispatch[k] += 18; /* flag as joint */ + m->cup.samp_dispatch[k + 1] = m->cup.samp_dispatch[k]; /* flag for sf */ + m->cup.c_value[k + 1] = m->cup.c_value[k]; + k++; + j++; + } + } + } + m->cup.samp_dispatch[m->cup.nsb_limit] = 37; /* terminate the dispatcher with skip */ + m->cup.samp_dispatch[k] = 36; /* terminate the dispatcher */ + +} +/*-------------------------------------------------------------------------*/ +static void unpack_sfs(MPEG *m) /* unpack scale factor selectors */ +{ + int i; + for (i = 0; i < m->cup.max_sb; i++) + { + mac_load_check(2); + if (m->cup.ballo[i]) + m->cup.sf_dispatch[i] = mac_load(2); + else + m->cup.sf_dispatch[i] = 4; /* no allo */ + } + m->cup.sf_dispatch[i] = 5; /* terminate dispatcher */ +} +/*-------------------------------------------------------------------------*/ +static void unpack_sf(MPEG *m) /* unpack scale factor */ +{ /* combine dequant and scale factors */ + int i; + + i = -1; + dispatch:switch (m->cup.sf_dispatch[++i]) + { + case 0: /* 3 factors 012 */ + mac_load_check(18); + m->cup.cs_factor[0][i] = m->cup.c_value[i] * m->cup.sf_table[mac_load(6)]; + m->cup.cs_factor[1][i] = m->cup.c_value[i] * m->cup.sf_table[mac_load(6)]; + m->cup.cs_factor[2][i] = m->cup.c_value[i] * m->cup.sf_table[mac_load(6)]; + goto dispatch; + case 1: /* 2 factors 002 */ + mac_load_check(12); + m->cup.cs_factor[1][i] = m->cup.cs_factor[0][i] = m->cup.c_value[i] * m->cup.sf_table[mac_load(6)]; + m->cup.cs_factor[2][i] = m->cup.c_value[i] * m->cup.sf_table[mac_load(6)]; + goto dispatch; + case 2: /* 1 factor 000 */ + mac_load_check(6); + m->cup.cs_factor[2][i] = m->cup.cs_factor[1][i] = m->cup.cs_factor[0][i] = + m->cup.c_value[i] * m->cup.sf_table[mac_load(6)]; + goto dispatch; + case 3: /* 2 factors 022 */ + mac_load_check(12); + m->cup.cs_factor[0][i] = m->cup.c_value[i] * m->cup.sf_table[mac_load(6)]; + m->cup.cs_factor[2][i] = m->cup.cs_factor[1][i] = m->cup.c_value[i] * m->cup.sf_table[mac_load(6)]; + goto dispatch; + case 4: /* no allo */ +/*-- m->cup.cs_factor[2][i] = m->cup.cs_factor[1][i] = m->cup.cs_factor[0][i] = 0.0; --*/ + goto dispatch; + case 5: /* all done */ + ; + } /* end switch */ +} +/*-------------------------------------------------------------------------*/ +#define UNPACK_N(n) s[k] = m->cup.cs_factor[i][k]*(load(m,n)-((1 << (n-1)) -1)); \ + s[k+64] = m->cup.cs_factor[i][k]*(load(m,n)-((1 << (n-1)) -1)); \ + s[k+128] = m->cup.cs_factor[i][k]*(load(m,n)-((1 << (n-1)) -1)); \ + goto dispatch; +#define UNPACK_N2(n) mac_load_check(3*n); \ + s[k] = m->cup.cs_factor[i][k]*(mac_load(n)-((1 << (n-1)) -1)); \ + s[k+64] = m->cup.cs_factor[i][k]*(mac_load(n)-((1 << (n-1)) -1)); \ + s[k+128] = m->cup.cs_factor[i][k]*(mac_load(n)-((1 << (n-1)) -1)); \ + goto dispatch; +#define UNPACK_N3(n) mac_load_check(2*n); \ + s[k] = m->cup.cs_factor[i][k]*(mac_load(n)-((1 << (n-1)) -1)); \ + s[k+64] = m->cup.cs_factor[i][k]*(mac_load(n)-((1 << (n-1)) -1)); \ + mac_load_check(n); \ + s[k+128] = m->cup.cs_factor[i][k]*(mac_load(n)-((1 << (n-1)) -1)); \ + goto dispatch; +#define UNPACKJ_N(n) tmp = (load(m,n)-((1 << (n-1)) -1)); \ + s[k] = m->cup.cs_factor[i][k]*tmp; \ + s[k+1] = m->cup.cs_factor[i][k+1]*tmp; \ + tmp = (load(m,n)-((1 << (n-1)) -1)); \ + s[k+64] = m->cup.cs_factor[i][k]*tmp; \ + s[k+64+1] = m->cup.cs_factor[i][k+1]*tmp; \ + tmp = (load(m,n)-((1 << (n-1)) -1)); \ + s[k+128] = m->cup.cs_factor[i][k]*tmp; \ + s[k+128+1] = m->cup.cs_factor[i][k+1]*tmp; \ + k++; /* skip right chan dispatch */ \ + goto dispatch; +/*-------------------------------------------------------------------------*/ +static void unpack_samp(MPEG *m) /* unpack samples */ +{ + int i, j, k; + float *s; + int n; + long tmp; + + s = m->cup.sample; + for (i = 0; i < 3; i++) + { /* 3 groups of scale factors */ + for (j = 0; j < 4; j++) + { + k = -1; + dispatch:switch (m->cup.samp_dispatch[++k]) + { + case 0: + s[k + 128] = s[k + 64] = s[k] = 0.0F; + goto dispatch; + case 1: /* 3 levels grouped 5 bits */ + mac_load_check(5); + n = mac_load(5); + s[k] = m->cup.cs_factor[i][k] * m->cup.group3_table[n][0]; + s[k + 64] = m->cup.cs_factor[i][k] * m->cup.group3_table[n][1]; + s[k + 128] = m->cup.cs_factor[i][k] * m->cup.group3_table[n][2]; + goto dispatch; + case 2: /* 5 levels grouped 7 bits */ + mac_load_check(7); + n = mac_load(7); + s[k] = m->cup.cs_factor[i][k] * m->cup.group5_table[n][0]; + s[k + 64] = m->cup.cs_factor[i][k] * m->cup.group5_table[n][1]; + s[k + 128] = m->cup.cs_factor[i][k] * m->cup.group5_table[n][2]; + goto dispatch; + case 3: + UNPACK_N2(3) /* 7 levels */ + case 4: /* 9 levels grouped 10 bits */ + mac_load_check(10); + n = mac_load(10); + s[k] = m->cup.cs_factor[i][k] * m->cup.group9_table[n][0]; + s[k + 64] = m->cup.cs_factor[i][k] * m->cup.group9_table[n][1]; + s[k + 128] = m->cup.cs_factor[i][k] * m->cup.group9_table[n][2]; + goto dispatch; + case 5: + UNPACK_N2(4) /* 15 levels */ + case 6: + UNPACK_N2(5) /* 31 levels */ + case 7: + UNPACK_N2(6) /* 63 levels */ + case 8: + UNPACK_N2(7) /* 127 levels */ + case 9: + UNPACK_N2(8) /* 255 levels */ + case 10: + UNPACK_N3(9) /* 511 levels */ + case 11: + UNPACK_N3(10) /* 1023 levels */ + case 12: + UNPACK_N3(11) /* 2047 levels */ + case 13: + UNPACK_N3(12) /* 4095 levels */ + case 14: + UNPACK_N(13) /* 8191 levels */ + case 15: + UNPACK_N(14) /* 16383 levels */ + case 16: + UNPACK_N(15) /* 32767 levels */ + case 17: + UNPACK_N(16) /* 65535 levels */ +/* -- joint ---- */ + case 18 + 0: + s[k + 128 + 1] = s[k + 128] = s[k + 64 + 1] = s[k + 64] = s[k + 1] = s[k] = 0.0F; + k++; /* skip right chan dispatch */ + goto dispatch; + case 18 + 1: /* 3 levels grouped 5 bits */ + n = load(m,5); + s[k] = m->cup.cs_factor[i][k] * m->cup.group3_table[n][0]; + s[k + 1] = m->cup.cs_factor[i][k + 1] * m->cup.group3_table[n][0]; + s[k + 64] = m->cup.cs_factor[i][k] * m->cup.group3_table[n][1]; + s[k + 64 + 1] = m->cup.cs_factor[i][k + 1] * m->cup.group3_table[n][1]; + s[k + 128] = m->cup.cs_factor[i][k] * m->cup.group3_table[n][2]; + s[k + 128 + 1] = m->cup.cs_factor[i][k + 1] * m->cup.group3_table[n][2]; + k++; /* skip right chan dispatch */ + goto dispatch; + case 18 + 2: /* 5 levels grouped 7 bits */ + n = load(m,7); + s[k] = m->cup.cs_factor[i][k] * m->cup.group5_table[n][0]; + s[k + 1] = m->cup.cs_factor[i][k + 1] * m->cup.group5_table[n][0]; + s[k + 64] = m->cup.cs_factor[i][k] * m->cup.group5_table[n][1]; + s[k + 64 + 1] = m->cup.cs_factor[i][k + 1] * m->cup.group5_table[n][1]; + s[k + 128] = m->cup.cs_factor[i][k] * m->cup.group5_table[n][2]; + s[k + 128 + 1] = m->cup.cs_factor[i][k + 1] * m->cup.group5_table[n][2]; + k++; /* skip right chan dispatch */ + goto dispatch; + case 18 + 3: + UNPACKJ_N(3) /* 7 levels */ + case 18 + 4: /* 9 levels grouped 10 bits */ + n = load(m,10); + s[k] = m->cup.cs_factor[i][k] * m->cup.group9_table[n][0]; + s[k + 1] = m->cup.cs_factor[i][k + 1] * m->cup.group9_table[n][0]; + s[k + 64] = m->cup.cs_factor[i][k] * m->cup.group9_table[n][1]; + s[k + 64 + 1] = m->cup.cs_factor[i][k + 1] * m->cup.group9_table[n][1]; + s[k + 128] = m->cup.cs_factor[i][k] * m->cup.group9_table[n][2]; + s[k + 128 + 1] = m->cup.cs_factor[i][k + 1] * m->cup.group9_table[n][2]; + k++; /* skip right chan dispatch */ + goto dispatch; + case 18 + 5: + UNPACKJ_N(4) /* 15 levels */ + case 18 + 6: + UNPACKJ_N(5) /* 31 levels */ + case 18 + 7: + UNPACKJ_N(6) /* 63 levels */ + case 18 + 8: + UNPACKJ_N(7) /* 127 levels */ + case 18 + 9: + UNPACKJ_N(8) /* 255 levels */ + case 18 + 10: + UNPACKJ_N(9) /* 511 levels */ + case 18 + 11: + UNPACKJ_N(10) /* 1023 levels */ + case 18 + 12: + UNPACKJ_N(11) /* 2047 levels */ + case 18 + 13: + UNPACKJ_N(12) /* 4095 levels */ + case 18 + 14: + UNPACKJ_N(13) /* 8191 levels */ + case 18 + 15: + UNPACKJ_N(14) /* 16383 levels */ + case 18 + 16: + UNPACKJ_N(15) /* 32767 levels */ + case 18 + 17: + UNPACKJ_N(16) /* 65535 levels */ +/* -- end of dispatch -- */ + case 37: + skip(m, m->cup.bit_skip); + case 36: + s += 3 * 64; + } /* end switch */ + } /* end j loop */ + } /* end i loop */ + + +} +/*-------------------------------------------------------------------------*/ +IN_OUT audio_decode(MPEG *m, unsigned char *bs, signed short *pcm) +{ + return m->cup.audio_decode_routine(m, bs, pcm); +} +/*-------------------------------------------------------------------------*/ +IN_OUT L2audio_decode(void *mv, unsigned char *bs, signed short *pcm) +{ + MPEG *m = mv; + int sync, prot; + IN_OUT in_out; + + load_init(m, bs); /* initialize bit getter */ +/* test sync */ + in_out.in_bytes = 0; /* assume fail */ + in_out.out_bytes = 0; + sync = load(m,12); + if (sync != 0xFFF) + return in_out; /* sync fail */ + + load(m,3); /* skip id and option (checked by init) */ + prot = load(m,1); /* load prot bit */ + load(m,6); /* skip to pad */ + m->cup.pad = load(m,1); + load(m,1); /* skip to mode */ + m->cup.stereo_sb = look_joint[load(m,4)]; + if (prot) + load(m,4); /* skip to data */ + else + load(m,20); /* skip crc */ + + unpack_ba(m); /* unpack bit allocation */ + unpack_sfs(m); /* unpack scale factor selectors */ + unpack_sf(m); /* unpack scale factor */ + unpack_samp(m); /* unpack samples */ + + m->cup.sbt(m, m->cup.sample, pcm, 36); +/*-----------*/ + in_out.in_bytes = m->cup.framebytes + m->cup.pad; + in_out.out_bytes = m->cup.outbytes; + + return in_out; +} +/*-------------------------------------------------------------------------*/ +#include "cupini.c" /* initialization */ +#include "cupL1.c" /* Layer I */ +/*-------------------------------------------------------------------------*/ |