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vdr/ac3dec/parse.c

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C
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2001-08-03 14:18:08 +02:00
/*
* parse.c
*
* Copyright (C) Aaron Holtzman - May 1999
*
* This file is part of ac3dec, a free Dolby AC-3 stream decoder.
*
* ac3dec 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, or (at your option)
* any later version.
*
* ac3dec 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 GNU Make; see the file COPYING. If not, write to
* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*
*
*/
#include <stdlib.h>
#include <stdio.h>
#include "ac3.h"
#include "ac3_internal.h"
#include "bitstream.h"
#include "stats.h"
#include "debug.h"
#include "parse.h"
/* Misc LUT */
static const uint_16 nfchans[8] = {2,1,2,3,3,4,4,5};
struct frmsize_s
{
uint_16 bit_rate;
uint_16 frm_size[3];
};
static const struct frmsize_s frmsizecod_tbl[64] =
{
{ 32 ,{64 ,69 ,96 } },
{ 32 ,{64 ,70 ,96 } },
{ 40 ,{80 ,87 ,120 } },
{ 40 ,{80 ,88 ,120 } },
{ 48 ,{96 ,104 ,144 } },
{ 48 ,{96 ,105 ,144 } },
{ 56 ,{112 ,121 ,168 } },
{ 56 ,{112 ,122 ,168 } },
{ 64 ,{128 ,139 ,192 } },
{ 64 ,{128 ,140 ,192 } },
{ 80 ,{160 ,174 ,240 } },
{ 80 ,{160 ,175 ,240 } },
{ 96 ,{192 ,208 ,288 } },
{ 96 ,{192 ,209 ,288 } },
{ 112 ,{224 ,243 ,336 } },
{ 112 ,{224 ,244 ,336 } },
{ 128 ,{256 ,278 ,384 } },
{ 128 ,{256 ,279 ,384 } },
{ 160 ,{320 ,348 ,480 } },
{ 160 ,{320 ,349 ,480 } },
{ 192 ,{384 ,417 ,576 } },
{ 192 ,{384 ,418 ,576 } },
{ 224 ,{448 ,487 ,672 } },
{ 224 ,{448 ,488 ,672 } },
{ 256 ,{512 ,557 ,768 } },
{ 256 ,{512 ,558 ,768 } },
{ 320 ,{640 ,696 ,960 } },
{ 320 ,{640 ,697 ,960 } },
{ 384 ,{768 ,835 ,1152 } },
{ 384 ,{768 ,836 ,1152 } },
{ 448 ,{896 ,975 ,1344 } },
{ 448 ,{896 ,976 ,1344 } },
{ 512 ,{1024 ,1114 ,1536 } },
{ 512 ,{1024 ,1115 ,1536 } },
{ 576 ,{1152 ,1253 ,1728 } },
{ 576 ,{1152 ,1254 ,1728 } },
{ 640 ,{1280 ,1393 ,1920 } },
{ 640 ,{1280 ,1394 ,1920 } }
};
/* Parse a syncinfo structure, minus the sync word */
void
parse_syncinfo(syncinfo_t *syncinfo,uint_8 *data)
{
//
// We need to read in the entire syncinfo struct (0x0b77 + 24 bits)
// in order to determine how big the frame is
//
// Get the sampling rate
syncinfo->fscod = (data[2] >> 6) & 0x3;
if(syncinfo->fscod == 3)
{
//invalid sampling rate code
error_flag = 1;
return;
}
else if(syncinfo->fscod == 2)
syncinfo->sampling_rate = 32000;
else if(syncinfo->fscod == 1)
syncinfo->sampling_rate = 44100;
else
syncinfo->sampling_rate = 48000;
// Get the frame size code
syncinfo->frmsizecod = data[2] & 0x3f;
// Calculate the frame size and bitrate
syncinfo->frame_size =
frmsizecod_tbl[syncinfo->frmsizecod].frm_size[syncinfo->fscod];
syncinfo->bit_rate = frmsizecod_tbl[syncinfo->frmsizecod].bit_rate;
}
/*
* This routine fills a bsi struct from the AC3 stream
*/
void
parse_bsi(bsi_t *bsi)
{
uint_32 i;
/* Check the AC-3 version number */
bsi->bsid = bitstream_get(5);
/* Get the audio service provided by the steram */
bsi->bsmod = bitstream_get(3);
/* Get the audio coding mode (ie how many channels)*/
bsi->acmod = bitstream_get(3);
/* Predecode the number of full bandwidth channels as we use this
* number a lot */
bsi->nfchans = nfchans[bsi->acmod];
/* If it is in use, get the centre channel mix level */
if ((bsi->acmod & 0x1) && (bsi->acmod != 0x1))
bsi->cmixlev = bitstream_get(2);
/* If it is in use, get the surround channel mix level */
if (bsi->acmod & 0x4)
bsi->surmixlev = bitstream_get(2);
/* Get the dolby surround mode if in 2/0 mode */
if(bsi->acmod == 0x2)
bsi->dsurmod= bitstream_get(2);
/* Is the low frequency effects channel on? */
bsi->lfeon = bitstream_get(1);
/* Get the dialogue normalization level */
bsi->dialnorm = bitstream_get(5);
/* Does compression gain exist? */
bsi->compre = bitstream_get(1);
if (bsi->compre)
{
/* Get compression gain */
bsi->compr = bitstream_get(8);
}
/* Does language code exist? */
bsi->langcode = bitstream_get(1);
if (bsi->langcode)
{
/* Get langauge code */
bsi->langcod = bitstream_get(8);
}
/* Does audio production info exist? */
bsi->audprodie = bitstream_get(1);
if (bsi->audprodie)
{
/* Get mix level */
bsi->mixlevel = bitstream_get(5);
/* Get room type */
bsi->roomtyp = bitstream_get(2);
}
/* If we're in dual mono mode then get some extra info */
if (bsi->acmod ==0)
{
/* Get the dialogue normalization level two */
bsi->dialnorm2 = bitstream_get(5);
/* Does compression gain two exist? */
bsi->compr2e = bitstream_get(1);
if (bsi->compr2e)
{
/* Get compression gain two */
bsi->compr2 = bitstream_get(8);
}
/* Does language code two exist? */
bsi->langcod2e = bitstream_get(1);
if (bsi->langcod2e)
{
/* Get langauge code two */
bsi->langcod2 = bitstream_get(8);
}
/* Does audio production info two exist? */
bsi->audprodi2e = bitstream_get(1);
if (bsi->audprodi2e)
{
/* Get mix level two */
bsi->mixlevel2 = bitstream_get(5);
/* Get room type two */
bsi->roomtyp2 = bitstream_get(2);
}
}
/* Get the copyright bit */
bsi->copyrightb = bitstream_get(1);
/* Get the original bit */
bsi->origbs = bitstream_get(1);
/* Does timecode one exist? */
bsi->timecod1e = bitstream_get(1);
if(bsi->timecod1e)
bsi->timecod1 = bitstream_get(14);
/* Does timecode two exist? */
bsi->timecod2e = bitstream_get(1);
if(bsi->timecod2e)
bsi->timecod2 = bitstream_get(14);
/* Does addition info exist? */
bsi->addbsie = bitstream_get(1);
if(bsi->addbsie)
{
/* Get how much info is there */
bsi->addbsil = bitstream_get(6);
/* Get the additional info */
for(i=0;i<(bsi->addbsil + 1);i++)
bsi->addbsi[i] = bitstream_get(8);
}
stats_print_bsi(bsi);
}
/* More pain inducing parsing */
void
parse_audblk(bsi_t *bsi,audblk_t *audblk)
{
int i,j;
for (i=0;i < bsi->nfchans; i++)
{
/* Is this channel an interleaved 256 + 256 block ? */
audblk->blksw[i] = bitstream_get(1);
}
for (i=0;i < bsi->nfchans; i++)
{
/* Should we dither this channel? */
audblk->dithflag[i] = bitstream_get(1);
}
/* Does dynamic range control exist? */
audblk->dynrnge = bitstream_get(1);
if (audblk->dynrnge)
{
/* Get dynamic range info */
audblk->dynrng = bitstream_get(8);
}
/* If we're in dual mono mode then get the second channel DR info */
if (bsi->acmod == 0)
{
/* Does dynamic range control two exist? */
audblk->dynrng2e = bitstream_get(1);
if (audblk->dynrng2e)
{
/* Get dynamic range info */
audblk->dynrng2 = bitstream_get(8);
}
}
/* Does coupling strategy exist? */
audblk->cplstre = bitstream_get(1);
if (audblk->cplstre)
{
/* Is coupling turned on? */
audblk->cplinu = bitstream_get(1);
if(audblk->cplinu)
{
for(i=0;i < bsi->nfchans; i++)
audblk->chincpl[i] = bitstream_get(1);
if(bsi->acmod == 0x2)
audblk->phsflginu = bitstream_get(1);
audblk->cplbegf = bitstream_get(4);
audblk->cplendf = bitstream_get(4);
audblk->ncplsubnd = (audblk->cplendf + 2) - audblk->cplbegf + 1;
/* Calculate the start and end bins of the coupling channel */
audblk->cplstrtmant = (audblk->cplbegf * 12) + 37 ;
audblk->cplendmant = ((audblk->cplendf + 3) * 12) + 37;
/* The number of combined subbands is ncplsubnd minus each combined
* band */
audblk->ncplbnd = audblk->ncplsubnd;
for(i=1; i< audblk->ncplsubnd; i++)
{
audblk->cplbndstrc[i] = bitstream_get(1);
audblk->ncplbnd -= audblk->cplbndstrc[i];
}
}
}
if(audblk->cplinu)
{
/* Loop through all the channels and get their coupling co-ords */
for(i=0;i < bsi->nfchans;i++)
{
if(!audblk->chincpl[i])
continue;
/* Is there new coupling co-ordinate info? */
audblk->cplcoe[i] = bitstream_get(1);
if(audblk->cplcoe[i])
{
audblk->mstrcplco[i] = bitstream_get(2);
for(j=0;j < audblk->ncplbnd; j++)
{
audblk->cplcoexp[i][j] = bitstream_get(4);
audblk->cplcomant[i][j] = bitstream_get(4);
}
}
}
/* If we're in dual mono mode, there's going to be some phase info */
if( (bsi->acmod == 0x2) && audblk->phsflginu &&
(audblk->cplcoe[0] || audblk->cplcoe[1]))
{
for(j=0;j < audblk->ncplbnd; j++)
audblk->phsflg[j] = bitstream_get(1);
}
}
/* If we're in dual mono mode, there may be a rematrix strategy */
if(bsi->acmod == 0x2)
{
audblk->rematstr = bitstream_get(1);
if(audblk->rematstr)
{
if (audblk->cplinu == 0)
{
for(i = 0; i < 4; i++)
audblk->rematflg[i] = bitstream_get(1);
}
if((audblk->cplbegf > 2) && audblk->cplinu)
{
for(i = 0; i < 4; i++)
audblk->rematflg[i] = bitstream_get(1);
}
if((audblk->cplbegf <= 2) && audblk->cplinu)
{
for(i = 0; i < 3; i++)
audblk->rematflg[i] = bitstream_get(1);
}
if((audblk->cplbegf == 0) && audblk->cplinu)
for(i = 0; i < 2; i++)
audblk->rematflg[i] = bitstream_get(1);
}
}
if (audblk->cplinu)
{
/* Get the coupling channel exponent strategy */
audblk->cplexpstr = bitstream_get(2);
audblk->ncplgrps = (audblk->cplendmant - audblk->cplstrtmant) /
(3 << (audblk->cplexpstr-1));
}
for(i = 0; i < bsi->nfchans; i++)
audblk->chexpstr[i] = bitstream_get(2);
/* Get the exponent strategy for lfe channel */
if(bsi->lfeon)
audblk->lfeexpstr = bitstream_get(1);
/* Determine the bandwidths of all the fbw channels */
for(i = 0; i < bsi->nfchans; i++)
{
uint_16 grp_size;
if(audblk->chexpstr[i] != EXP_REUSE)
{
if (audblk->cplinu && audblk->chincpl[i])
{
audblk->endmant[i] = audblk->cplstrtmant;
}
else
{
audblk->chbwcod[i] = bitstream_get(6);
audblk->endmant[i] = ((audblk->chbwcod[i] + 12) * 3) + 37;
}
/* Calculate the number of exponent groups to fetch */
grp_size = 3 * (1 << (audblk->chexpstr[i] - 1));
audblk->nchgrps[i] = (audblk->endmant[i] - 1 + (grp_size - 3)) / grp_size;
}
}
/* Get the coupling exponents if they exist */
if(audblk->cplinu && (audblk->cplexpstr != EXP_REUSE))
{
audblk->cplabsexp = bitstream_get(4);
for(i=0;i< audblk->ncplgrps;i++)
audblk->cplexps[i] = bitstream_get(7);
}
/* Get the fwb channel exponents */
for(i=0;i < bsi->nfchans; i++)
{
if(audblk->chexpstr[i] != EXP_REUSE)
{
audblk->exps[i][0] = bitstream_get(4);
for(j=1;j<=audblk->nchgrps[i];j++)
audblk->exps[i][j] = bitstream_get(7);
audblk->gainrng[i] = bitstream_get(2);
}
}
/* Get the lfe channel exponents */
if(bsi->lfeon && (audblk->lfeexpstr != EXP_REUSE))
{
audblk->lfeexps[0] = bitstream_get(4);
audblk->lfeexps[1] = bitstream_get(7);
audblk->lfeexps[2] = bitstream_get(7);
}
/* Get the parametric bit allocation parameters */
audblk->baie = bitstream_get(1);
if(audblk->baie)
{
audblk->sdcycod = bitstream_get(2);
audblk->fdcycod = bitstream_get(2);
audblk->sgaincod = bitstream_get(2);
audblk->dbpbcod = bitstream_get(2);
audblk->floorcod = bitstream_get(3);
}
/* Get the SNR off set info if it exists */
audblk->snroffste = bitstream_get(1);
if(audblk->snroffste)
{
audblk->csnroffst = bitstream_get(6);
if(audblk->cplinu)
{
audblk->cplfsnroffst = bitstream_get(4);
audblk->cplfgaincod = bitstream_get(3);
}
for(i = 0;i < bsi->nfchans; i++)
{
audblk->fsnroffst[i] = bitstream_get(4);
audblk->fgaincod[i] = bitstream_get(3);
}
if(bsi->lfeon)
{
audblk->lfefsnroffst = bitstream_get(4);
audblk->lfefgaincod = bitstream_get(3);
}
}
/* Get coupling leakage info if it exists */
if(audblk->cplinu)
{
audblk->cplleake = bitstream_get(1);
if(audblk->cplleake)
{
audblk->cplfleak = bitstream_get(3);
audblk->cplsleak = bitstream_get(3);
}
}
/* Get the delta bit alloaction info */
audblk->deltbaie = bitstream_get(1);
if(audblk->deltbaie)
{
if(audblk->cplinu)
audblk->cpldeltbae = bitstream_get(2);
for(i = 0;i < bsi->nfchans; i++)
audblk->deltbae[i] = bitstream_get(2);
if (audblk->cplinu && (audblk->cpldeltbae == DELTA_BIT_NEW))
{
audblk->cpldeltnseg = bitstream_get(3);
for(i = 0;i < audblk->cpldeltnseg + 1; i++)
{
audblk->cpldeltoffst[i] = bitstream_get(5);
audblk->cpldeltlen[i] = bitstream_get(4);
audblk->cpldeltba[i] = bitstream_get(3);
}
}
for(i = 0;i < bsi->nfchans; i++)
{
if (audblk->deltbae[i] == DELTA_BIT_NEW)
{
audblk->deltnseg[i] = bitstream_get(3);
for(j = 0; j < audblk->deltnseg[i] + 1; j++)
{
audblk->deltoffst[i][j] = bitstream_get(5);
audblk->deltlen[i][j] = bitstream_get(4);
audblk->deltba[i][j] = bitstream_get(3);
}
}
}
}
/* Check to see if there's any dummy info to get */
if((audblk->skiple = bitstream_get(1)))
{
uint_16 skip_data;
audblk->skipl = bitstream_get(9);
//XXX remove
//fprintf(stderr,"(parse) skipping %d bytes\n",audblk->skipl);
for(i = 0; i < audblk->skipl ; i++)
{
skip_data = bitstream_get(8);
//XXX remove
//fprintf(stderr,"skipped data %2x\n",skip_data);
//if(skip_data != 0)
//{
//dprintf("(parse) Invalid skipped data %2x\n",skip_data);
//exit(1);
//}
}
}
stats_print_audblk(bsi,audblk);
}
void
parse_auxdata(syncinfo_t *syncinfo)
{
//FIXME keep this now that we don't really need it?
#if 0
int i;
int skip_length;
uint_16 crc;
uint_16 auxdatae;
skip_length = (syncinfo->frame_size * 16) - bitstream_get_total_bits() - 17 - 1;
//XXX remove
//dprintf("(auxdata) skipping %d auxbits\n",skip_length);
for(i=0; i < skip_length; i++)
//printf("Skipped bit %i\n",(uint_16)bitstream_get(1));
bitstream_get(1);
//get the auxdata exists bit
auxdatae = bitstream_get(1);
//XXX remove
//dprintf("auxdatae = %i\n",auxdatae);
//Skip the CRC reserved bit
bitstream_get(1);
//Get the crc
crc = bitstream_get(16);
#endif
}