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path: root/core/multimedia/opieplayer/libmpeg3/audio/ac3.c
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Diffstat (limited to 'core/multimedia/opieplayer/libmpeg3/audio/ac3.c') (more/less context) (ignore whitespace changes)
-rw-r--r--core/multimedia/opieplayer/libmpeg3/audio/ac3.c691
1 files changed, 691 insertions, 0 deletions
diff --git a/core/multimedia/opieplayer/libmpeg3/audio/ac3.c b/core/multimedia/opieplayer/libmpeg3/audio/ac3.c
new file mode 100644
index 0000000..7a3b664
--- a/dev/null
+++ b/core/multimedia/opieplayer/libmpeg3/audio/ac3.c
@@ -0,0 +1,691 @@
+/*
+ *
+ * ac3.c Copyright (C) Aaron Holtzman - May 1999
+ *
+ *
+ * This file is part of libmpeg3
+ *
+ * libmpeg3 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.
+ *
+ * libmpeg3 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 "mpeg3audio.h"
+#include "../libmpeg3.h"
+#include "../mpeg3protos.h"
+
+#include <math.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#define MPEG3AC3_MAGIC_NUMBER 0xdeadbeef
+
+
+int mpeg3_ac3_samplerates[] = { 48000, 44100, 32000 };
+
+struct mpeg3_framesize_s
+{
+ unsigned short bit_rate;
+ unsigned short frm_size[3];
+};
+
+struct mpeg3_framesize_s framesize_codes[] =
+{
+ { 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 } }
+};
+
+/* Audio channel modes */
+short mpeg3_ac3_acmodes[] = {2, 1, 2, 3, 3, 4, 4, 5};
+
+/* Rematrix tables */
+struct rematrix_band_s
+{
+ int start;
+ int end;
+};
+
+struct rematrix_band_s mpeg3_rematrix_band[] =
+{
+ {13, 24},
+ {25, 36},
+ {37, 60},
+ {61, 252}
+};
+
+int mpeg3_min(int x, int y)
+{
+ return (x < y) ? x : y;
+}
+
+int mpeg3_max(int x, int y)
+{
+ return (x > y) ? x : y;
+}
+
+int mpeg3audio_read_ac3_header(mpeg3audio_t *audio)
+{
+ unsigned int code, crc;
+ unsigned int i;
+ mpeg3_ac3bsi_t *bsi = &(audio->ac3_bsi);
+
+/* Get the sync code */
+ code = mpeg3bits_getbits(audio->astream, 16);
+ while(!mpeg3bits_eof(audio->astream) && code != MPEG3_AC3_START_CODE)
+ {
+ code <<= 8;
+ code &= 0xffff;
+ code |= mpeg3bits_getbits(audio->astream, 8);
+ }
+
+ if(mpeg3bits_eof(audio->astream)) return 1;
+
+/* Get crc1 - we don't actually use this data though */
+/* The crc can be the same as the sync code or come after a sync code repeated twice */
+ crc = mpeg3bits_getbits(audio->astream, 16);
+
+/* Got the sync code. Read the entire frame into a buffer if possible. */
+ if(audio->avg_framesize > 0)
+ {
+ if(mpeg3bits_read_buffer(audio->astream, audio->ac3_buffer, audio->framesize - 4))
+ return 1;
+ mpeg3bits_use_ptr(audio->astream, audio->ac3_buffer);
+ }
+
+/* Get the sampling rate code */
+ audio->sampling_frequency_code = mpeg3bits_getbits(audio->astream, 2);
+
+/* Get the frame size code */
+ audio->ac3_framesize_code = mpeg3bits_getbits(audio->astream, 6);
+
+ audio->bitrate = framesize_codes[audio->ac3_framesize_code].bit_rate;
+ audio->avg_framesize = audio->framesize = 2 * framesize_codes[audio->ac3_framesize_code].frm_size[audio->sampling_frequency_code];
+
+/* Check the AC-3 version number */
+ bsi->bsid = mpeg3bits_getbits(audio->astream, 5);
+
+/* Get the audio service provided by the steram */
+ bsi->bsmod = mpeg3bits_getbits(audio->astream, 3);
+
+/* Get the audio coding mode (ie how many channels)*/
+ bsi->acmod = mpeg3bits_getbits(audio->astream, 3);
+
+/* Predecode the number of full bandwidth channels as we use this
+ * number a lot */
+ bsi->nfchans = mpeg3_ac3_acmodes[bsi->acmod];
+ audio->channels = bsi->nfchans;
+
+/* If it is in use, get the centre channel mix level */
+ if((bsi->acmod & 0x1) && (bsi->acmod != 0x1))
+ bsi->cmixlev = mpeg3bits_getbits(audio->astream, 2);
+
+/* If it is in use, get the surround channel mix level */
+ if(bsi->acmod & 0x4)
+ bsi->surmixlev = mpeg3bits_getbits(audio->astream, 2);
+
+/* Get the dolby surround mode if in 2/0 mode */
+ if(bsi->acmod == 0x2)
+ bsi->dsurmod= mpeg3bits_getbits(audio->astream, 2);
+
+/* Is the low frequency effects channel on? */
+ bsi->lfeon = mpeg3bits_getbits(audio->astream, 1);
+
+/* Get the dialogue normalization level */
+ bsi->dialnorm = mpeg3bits_getbits(audio->astream, 5);
+
+/* Does compression gain exist? */
+ bsi->compre = mpeg3bits_getbits(audio->astream, 1);
+ if (bsi->compre)
+ {
+/* Get compression gain */
+ bsi->compr = mpeg3bits_getbits(audio->astream, 8);
+ }
+
+/* Does language code exist? */
+ bsi->langcode = mpeg3bits_getbits(audio->astream, 1);
+ if (bsi->langcode)
+ {
+/* Get langauge code */
+ bsi->langcod = mpeg3bits_getbits(audio->astream, 8);
+ }
+
+/* Does audio production info exist? */
+ bsi->audprodie = mpeg3bits_getbits(audio->astream, 1);
+ if (bsi->audprodie)
+ {
+/* Get mix level */
+ bsi->mixlevel = mpeg3bits_getbits(audio->astream, 5);
+
+/* Get room type */
+ bsi->roomtyp = mpeg3bits_getbits(audio->astream, 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 = mpeg3bits_getbits(audio->astream, 5);
+
+/* Does compression gain two exist? */
+ bsi->compr2e = mpeg3bits_getbits(audio->astream, 1);
+ if (bsi->compr2e)
+ {
+/* Get compression gain two */
+ bsi->compr2 = mpeg3bits_getbits(audio->astream, 8);
+ }
+
+/* Does language code two exist? */
+ bsi->langcod2e = mpeg3bits_getbits(audio->astream, 1);
+ if (bsi->langcod2e)
+ {
+/* Get langauge code two */
+ bsi->langcod2 = mpeg3bits_getbits(audio->astream, 8);
+ }
+
+/* Does audio production info two exist? */
+ bsi->audprodi2e = mpeg3bits_getbits(audio->astream, 1);
+ if (bsi->audprodi2e)
+ {
+/* Get mix level two */
+ bsi->mixlevel2 = mpeg3bits_getbits(audio->astream, 5);
+
+/* Get room type two */
+ bsi->roomtyp2 = mpeg3bits_getbits(audio->astream, 2);
+ }
+ }
+
+/* Get the copyright bit */
+ bsi->copyrightb = mpeg3bits_getbits(audio->astream, 1);
+
+/* Get the original bit */
+ bsi->origbs = mpeg3bits_getbits(audio->astream, 1);
+
+/* Does timecode one exist? */
+ bsi->timecod1e = mpeg3bits_getbits(audio->astream, 1);
+
+ if(bsi->timecod1e)
+ bsi->timecod1 = mpeg3bits_getbits(audio->astream, 14);
+
+/* Does timecode two exist? */
+ bsi->timecod2e = mpeg3bits_getbits(audio->astream, 1);
+
+ if(bsi->timecod2e)
+ bsi->timecod2 = mpeg3bits_getbits(audio->astream, 14);
+
+/* Does addition info exist? */
+ bsi->addbsie = mpeg3bits_getbits(audio->astream, 1);
+
+ if(bsi->addbsie)
+ {
+/* Get how much info is there */
+ bsi->addbsil = mpeg3bits_getbits(audio->astream, 6);
+
+/* Get the additional info */
+ for(i = 0; i < (bsi->addbsil + 1); i++)
+ bsi->addbsi[i] = mpeg3bits_getbits(audio->astream, 8);
+ }
+
+ if(mpeg3bits_eof(audio->astream))
+ {
+ mpeg3bits_use_demuxer(audio->astream);
+ return 1;
+ }
+// return mpeg3bits_error(audio->astream);
+}
+
+int mpeg3audio_read_ac3_audblk(mpeg3audio_t *audio)
+{
+ int i, j;
+ mpeg3_ac3bsi_t *bsi = &(audio->ac3_bsi);
+ mpeg3_ac3audblk_t *audblk = &(audio->ac3_audblk);
+
+ for(i = 0; i < bsi->nfchans; i++)
+ {
+/* Is this channel an interleaved 256 + 256 block ? */
+ audblk->blksw[i] = mpeg3bits_getbits(audio->astream, 1);
+ }
+
+ for(i = 0; i < bsi->nfchans; i++)
+ {
+/* Should we dither this channel? */
+ audblk->dithflag[i] = mpeg3bits_getbits(audio->astream, 1);
+ }
+
+/* Does dynamic range control exist? */
+ audblk->dynrnge = mpeg3bits_getbits(audio->astream, 1);
+ if(audblk->dynrnge)
+ {
+/* Get dynamic range info */
+ audblk->dynrng = mpeg3bits_getbits(audio->astream, 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 = mpeg3bits_getbits(audio->astream, 1);
+ if (audblk->dynrng2e)
+ {
+/* Get dynamic range info */
+ audblk->dynrng2 = mpeg3bits_getbits(audio->astream, 8);
+ }
+ }
+
+/* Does coupling strategy exist? */
+ audblk->cplstre = mpeg3bits_getbits(audio->astream, 1);
+ if(audblk->cplstre)
+ {
+/* Is coupling turned on? */
+ audblk->cplinu = mpeg3bits_getbits(audio->astream, 1);
+ if(audblk->cplinu)
+ {
+ for(i = 0; i < bsi->nfchans; i++)
+ audblk->chincpl[i] = mpeg3bits_getbits(audio->astream, 1);
+
+ if(bsi->acmod == 0x2)
+ audblk->phsflginu = mpeg3bits_getbits(audio->astream, 1);
+
+ audblk->cplbegf = mpeg3bits_getbits(audio->astream, 4);
+ audblk->cplendf = mpeg3bits_getbits(audio->astream, 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] = mpeg3bits_getbits(audio->astream, 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] = mpeg3bits_getbits(audio->astream, 1);
+
+ if(audblk->cplcoe[i])
+ {
+ audblk->mstrcplco[i] = mpeg3bits_getbits(audio->astream, 2);
+ for(j = 0; j < audblk->ncplbnd; j++)
+ {
+ audblk->cplcoexp[i][j] = mpeg3bits_getbits(audio->astream, 4);
+ audblk->cplcomant[i][j] = mpeg3bits_getbits(audio->astream, 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] = mpeg3bits_getbits(audio->astream, 1);
+ }
+ }
+ }
+
+/* If we're in dual mono mode, there may be a rematrix strategy */
+ if(bsi->acmod == 0x2)
+ {
+ audblk->rematstr = mpeg3bits_getbits(audio->astream, 1);
+ if(audblk->rematstr)
+ {
+ if (audblk->cplinu == 0)
+ {
+ for(i = 0; i < 4; i++)
+ audblk->rematflg[i] = mpeg3bits_getbits(audio->astream, 1);
+ }
+ if((audblk->cplbegf > 2) && audblk->cplinu)
+ {
+ for(i = 0; i < 4; i++)
+ audblk->rematflg[i] = mpeg3bits_getbits(audio->astream, 1);
+ }
+ if((audblk->cplbegf <= 2) && audblk->cplinu)
+ {
+ for(i = 0; i < 3; i++)
+ audblk->rematflg[i] = mpeg3bits_getbits(audio->astream, 1);
+ }
+ if((audblk->cplbegf == 0) && audblk->cplinu)
+ for(i = 0; i < 2; i++)
+ audblk->rematflg[i] = mpeg3bits_getbits(audio->astream, 1);
+
+ }
+ }
+
+ if (audblk->cplinu)
+ {
+/* Get the coupling channel exponent strategy */
+ audblk->cplexpstr = mpeg3bits_getbits(audio->astream, 2);
+
+ if(audblk->cplexpstr == 0)
+ audblk->ncplgrps = 0;
+ else
+ audblk->ncplgrps = (audblk->cplendmant - audblk->cplstrtmant) /
+ (3 << (audblk->cplexpstr - 1));
+
+ }
+
+ for(i = 0; i < bsi->nfchans; i++)
+ {
+ audblk->chexpstr[i] = mpeg3bits_getbits(audio->astream, 2);
+ }
+
+/* Get the exponent strategy for lfe channel */
+ if(bsi->lfeon)
+ audblk->lfeexpstr = mpeg3bits_getbits(audio->astream, 1);
+
+/* Determine the bandwidths of all the fbw channels */
+ for(i = 0; i < bsi->nfchans; i++)
+ {
+ unsigned short grp_size;
+
+ if(audblk->chexpstr[i] != MPEG3_EXP_REUSE)
+ {
+ if (audblk->cplinu && audblk->chincpl[i])
+ {
+ audblk->endmant[i] = audblk->cplstrtmant;
+ }
+ else
+ {
+ audblk->chbwcod[i] = mpeg3bits_getbits(audio->astream, 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 != MPEG3_EXP_REUSE))
+ {
+ audblk->cplabsexp = mpeg3bits_getbits(audio->astream, 4);
+ for(i = 0; i< audblk->ncplgrps; i++)
+ audblk->cplexps[i] = mpeg3bits_getbits(audio->astream, 7);
+ }
+
+/* Get the fwb channel exponents */
+ for(i = 0; i < bsi->nfchans; i++)
+ {
+ if(audblk->chexpstr[i] != MPEG3_EXP_REUSE)
+ {
+ audblk->exps[i][0] = mpeg3bits_getbits(audio->astream, 4);
+ for(j = 1; j <= audblk->nchgrps[i]; j++)
+ audblk->exps[i][j] = mpeg3bits_getbits(audio->astream, 7);
+ audblk->gainrng[i] = mpeg3bits_getbits(audio->astream, 2);
+ }
+ }
+
+/* Get the lfe channel exponents */
+ if(bsi->lfeon && (audblk->lfeexpstr != MPEG3_EXP_REUSE))
+ {
+ audblk->lfeexps[0] = mpeg3bits_getbits(audio->astream, 4);
+ audblk->lfeexps[1] = mpeg3bits_getbits(audio->astream, 7);
+ audblk->lfeexps[2] = mpeg3bits_getbits(audio->astream, 7);
+ }
+
+/* Get the parametric bit allocation parameters */
+ audblk->baie = mpeg3bits_getbits(audio->astream, 1);
+
+ if(audblk->baie)
+ {
+ audblk->sdcycod = mpeg3bits_getbits(audio->astream, 2);
+ audblk->fdcycod = mpeg3bits_getbits(audio->astream, 2);
+ audblk->sgaincod = mpeg3bits_getbits(audio->astream, 2);
+ audblk->dbpbcod = mpeg3bits_getbits(audio->astream, 2);
+ audblk->floorcod = mpeg3bits_getbits(audio->astream, 3);
+ }
+
+
+/* Get the SNR off set info if it exists */
+ audblk->snroffste = mpeg3bits_getbits(audio->astream, 1);
+
+ if(audblk->snroffste)
+ {
+ audblk->csnroffst = mpeg3bits_getbits(audio->astream, 6);
+
+ if(audblk->cplinu)
+ {
+ audblk->cplfsnroffst = mpeg3bits_getbits(audio->astream, 4);
+ audblk->cplfgaincod = mpeg3bits_getbits(audio->astream, 3);
+ }
+
+ for(i = 0; i < bsi->nfchans; i++)
+ {
+ audblk->fsnroffst[i] = mpeg3bits_getbits(audio->astream, 4);
+ audblk->fgaincod[i] = mpeg3bits_getbits(audio->astream, 3);
+ }
+ if(bsi->lfeon)
+ {
+
+ audblk->lfefsnroffst = mpeg3bits_getbits(audio->astream, 4);
+ audblk->lfefgaincod = mpeg3bits_getbits(audio->astream, 3);
+ }
+ }
+
+/* Get coupling leakage info if it exists */
+ if(audblk->cplinu)
+ {
+ audblk->cplleake = mpeg3bits_getbits(audio->astream, 1);
+
+ if(audblk->cplleake)
+ {
+ audblk->cplfleak = mpeg3bits_getbits(audio->astream, 3);
+ audblk->cplsleak = mpeg3bits_getbits(audio->astream, 3);
+ }
+ }
+
+/* Get the delta bit alloaction info */
+ audblk->deltbaie = mpeg3bits_getbits(audio->astream, 1);
+
+ if(audblk->deltbaie)
+ {
+ if(audblk->cplinu)
+ audblk->cpldeltbae = mpeg3bits_getbits(audio->astream, 2);
+
+ for(i = 0; i < bsi->nfchans; i++)
+ audblk->deltbae[i] = mpeg3bits_getbits(audio->astream, 2);
+
+ if (audblk->cplinu && (audblk->cpldeltbae == DELTA_BIT_NEW))
+ {
+ audblk->cpldeltnseg = mpeg3bits_getbits(audio->astream, 3);
+ for(i = 0; i < audblk->cpldeltnseg + 1; i++)
+ {
+ audblk->cpldeltoffst[i] = mpeg3bits_getbits(audio->astream, 5);
+ audblk->cpldeltlen[i] = mpeg3bits_getbits(audio->astream, 4);
+ audblk->cpldeltba[i] = mpeg3bits_getbits(audio->astream, 3);
+ }
+ }
+
+ for(i = 0; i < bsi->nfchans; i++)
+ {
+ if (audblk->deltbae[i] == DELTA_BIT_NEW)
+ {
+ audblk->deltnseg[i] = mpeg3bits_getbits(audio->astream, 3);
+ for(j = 0; j < audblk->deltnseg[i] + 1; j++)
+ {
+ audblk->deltoffst[i][j] = mpeg3bits_getbits(audio->astream, 5);
+ audblk->deltlen[i][j] = mpeg3bits_getbits(audio->astream, 4);
+ audblk->deltba[i][j] = mpeg3bits_getbits(audio->astream, 3);
+ }
+ }
+ }
+ }
+
+/* Check to see if there's any dummy info to get */
+ if((audblk->skiple = mpeg3bits_getbits(audio->astream, 1)))
+ {
+ unsigned int skip_data;
+ audblk->skipl = mpeg3bits_getbits(audio->astream, 9);
+ for(i = 0; i < audblk->skipl ; i++)
+ {
+ skip_data = mpeg3bits_getbits(audio->astream, 8);
+ }
+ }
+
+ return mpeg3bits_error(audio->astream);
+}
+
+
+/* This routine simply does stereo rematrixing for the 2 channel
+ * stereo mode */
+int mpeg3audio_ac3_rematrix(mpeg3_ac3audblk_t *audblk,
+ mpeg3ac3_stream_samples_t samples)
+{
+ int num_bands;
+ int start;
+ int end;
+ int i, j;
+ mpeg3_real_t left, right;
+
+ if(audblk->cplinu || audblk->cplbegf > 2)
+ num_bands = 4;
+ else if (audblk->cplbegf > 0)
+ num_bands = 3;
+ else
+ num_bands = 2;
+
+ for(i = 0; i < num_bands; i++)
+ {
+ if(!audblk->rematflg[i])
+ continue;
+
+ start = mpeg3_rematrix_band[i].start;
+ end = mpeg3_min(mpeg3_rematrix_band[i].end, 12 * audblk->cplbegf + 36);
+
+ for(j = start; j < end; j++)
+ {
+ left = samples[0][j] + samples[1][j];
+ right = samples[0][j] - samples[1][j];
+ samples[0][j] = left;
+ samples[1][j] = right;
+ }
+ }
+ return 0;
+}
+
+
+int mpeg3audio_ac3_reset_frame(mpeg3audio_t *audio)
+{
+ memset(&audio->ac3_bit_allocation, 0, sizeof(mpeg3_ac3_bitallocation_t));
+ memset(&audio->ac3_mantissa, 0, sizeof(mpeg3_ac3_mantissa_t));
+ memset(&audio->ac3_audblk, 0, sizeof(mpeg3_ac3audblk_t));
+
+ return 0;
+}
+
+int mpeg3audio_do_ac3(mpeg3audio_t *audio)
+{
+ int result = 0, i;
+
+/* Reset the coefficients and exponents */
+ mpeg3audio_ac3_reset_frame(audio);
+
+ for(i = 0; i < 6 && !result; i++)
+ {
+ memset(audio->ac3_samples, 0, sizeof(mpeg3_real_t) * 256 * (audio->ac3_bsi.nfchans + audio->ac3_bsi.lfeon));
+/* Extract most of the audblk info from the bitstream
+ * (minus the mantissas */
+ result |= mpeg3audio_read_ac3_audblk(audio);
+
+/* Take the differential exponent data and turn it into
+ * absolute exponents */
+ if(!result) result |= mpeg3audio_ac3_exponent_unpack(audio,
+ &(audio->ac3_bsi),
+ &(audio->ac3_audblk));
+
+/* Figure out how many bits per mantissa */
+ if(!result) result |= mpeg3audio_ac3_bit_allocate(audio,
+ audio->sampling_frequency_code,
+ &(audio->ac3_bsi),
+ &(audio->ac3_audblk));
+
+/* Extract the mantissas from the data stream */
+ if(!result) result |= mpeg3audio_ac3_coeff_unpack(audio,
+ &(audio->ac3_bsi),
+ &(audio->ac3_audblk),
+ audio->ac3_samples);
+
+ if(audio->ac3_bsi.acmod == 0x2)
+ if(!result) result |= mpeg3audio_ac3_rematrix(&(audio->ac3_audblk),
+ audio->ac3_samples);
+
+/* Convert the frequency data into time samples */
+ if(!result) result |= mpeg3audio_ac3_imdct(audio,
+ &(audio->ac3_bsi),
+ &(audio->ac3_audblk),
+ audio->ac3_samples);
+
+ if(audio->pcm_point / audio->channels >= audio->pcm_allocated - MPEG3AUDIO_PADDING * audio->channels)
+ {
+/* Need more room */
+ mpeg3audio_replace_buffer(audio, audio->pcm_allocated + MPEG3AUDIO_PADDING * audio->channels);
+ }
+ }
+
+ mpeg3bits_use_demuxer(audio->astream);
+
+ return result;
+}