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-rw-r--r--ac3dec/parse.c597
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diff --git a/ac3dec/parse.c b/ac3dec/parse.c
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+++ b/ac3dec/parse.c
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+/*
+ * 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
+}
+
+
generated by cgit v1.2.3 (git 2.25.1) at 2024-09-21 19:57:53 +0000