int mpeg3audio_read_pcm_header(mpeg3audio_t *audio)
{
unsigned int code;
code = mpeg3bits_getbits(audio->astream, 16);
while(!mpeg3bits_eof(audio->astream) && code != MPEG3_PCM_START_CODE)
{
code <<= 8;
code &= 0xffff;
code |= mpeg3bits_getbits(audio->astream, 8);
}
audio->avg_framesize = audio->framesize = 0x7db;
audio->channels = 2;
return mpeg3bits_eof(audio->astream);
}
int mpeg3audio_dolayer2(mpeg3audio_t *audio)
{
int i, j, result = 0;
int channels = audio->channels;
float fraction[2][4][SBLIMIT]; /* pick_table clears unused subbands */
unsigned int bit_alloc[64];
int scale[192];
int single = audio->single;
if(audio->error_protection)
mpeg3bits_getbits(audio->astream, 16);
mpeg3audio_II_select_table(audio);
audio->jsbound = (audio->mode == MPG_MD_JOINT_STEREO) ?
(audio->mode_ext << 2) + 4 : audio->II_sblimit;
if(channels == 1 || single == 3)
single = 0;
result |= mpeg3audio_II_step_one(audio, bit_alloc, scale);
for(i = 0; i < SCALE_BLOCK && !result; i++)
{
result |= mpeg3audio_II_step_two(audio, bit_alloc, fraction, scale, i >> 2);
for(j = 0; j < 3; j++)
{
if(single >= 0)
{
/* Monaural */
mpeg3audio_synth_mono(audio, fraction[single][j], audio->pcm_sample, &(audio->pcm_point));
}
else
{
/* Stereo */
int p1 = audio->pcm_point;
mpeg3audio_synth_stereo(audio, fraction[0][j], 0, audio->pcm_sample, &p1);
mpeg3audio_synth_stereo(audio, fraction[1][j], 1, audio->pcm_sample, &(audio->pcm_point));
}
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);
}
}
}
return result;
}
int mpeg3audio_III_get_scale_factors_1(mpeg3audio_t *audio,
int *scf,
struct gr_info_s *gr_info,
int ch,
int gr)
{
static unsigned char slen[2][16] =
{{0, 0, 0, 0, 3, 1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4},
{0, 1, 2, 3, 0, 1, 2, 3, 1, 2, 3, 1, 2, 3, 2, 3}};
int numbits;
int num0 = slen[0][gr_info->scalefac_compress];
int num1 = slen[1][gr_info->scalefac_compress];
if (gr_info->block_type == 2)
{
int i = 18;
numbits = (num0 + num1) * 18;
if (gr_info->mixed_block_flag)
{
for(i = 8; i; i--)
*scf++ = mpeg3bits_getbits(audio->astream, num0);
i = 9;
/* num0 * 17 + num1 * 18 */
numbits -= num0;
}
for( ; i; i--)
*scf++ = mpeg3bits_getbits(audio->astream, num0);
for(i = 18; i; i--)
*scf++ = mpeg3bits_getbits(audio->astream, num1);
/* short[13][0..2] = 0 */
*scf++ = 0;
*scf++ = 0;
*scf++ = 0;
}
else
{
int i;
int scfsi = gr_info->scfsi;
if(scfsi < 0)
{
/* scfsi < 0 => granule == 0 */
for(i = 11; i; i--)
{
*scf++ = mpeg3bits_getbits(audio->astream, num0);
}
for(i = 10; i; i--)
*scf++ = mpeg3bits_getbits(audio->astream, num1);
numbits = (num0 + num1) * 10 + num0;
*scf++ = 0;
}
else
{
numbits = 0;
if(!(scfsi & 0x8))
{
for(i = 0; i < 6; i++)
{
*scf++ = mpeg3bits_getbits(audio->astream, num0);
}
numbits += num0 * 6;
}
else
{
scf += 6;
}
if(!(scfsi & 0x4))
{
for(i = 0; i < 5; i++)
*scf++ = mpeg3bits_getbits(audio->astream, num0);
numbits += num0 * 5;
}
else
{
scf += 5;
}
if(!(scfsi & 0x2))
{
for(i = 0; i < 5; i++)
*scf++ = mpeg3bits_getbits(audio->astream, num1);
numbits += num1 * 5;
}
else
{
scf += 5;
}
if(!(scfsi & 0x1))
{
for(i = 0; i < 5; i++)
*scf++ = mpeg3bits_getbits(audio->astream, num1);
numbits += num1 * 5;
}
else
{
scf += 5;
}
*scf++ = 0; /* no l[21] in original sources */
}
}
return numbits;
}
/* Fetch an unpacked, left justified, and properly biased/dithered mantissa value */
static unsigned short mpeg3audio_ac3_mantissa_get(mpeg3audio_t *audio,
unsigned short bap,
unsigned short dithflag)
{
unsigned short mantissa;
unsigned int group_code;
mpeg3_ac3_mantissa_t *mantissa_struct = &(audio->ac3_mantissa);
/* If the bap is 0-5 then we have special cases to take care of */
switch(bap)
{
case 0:
if(dithflag)
mantissa = mpeg3audio_ac3_dither_gen(audio);
else
mantissa = 0;
break;
case 1:
if(mantissa_struct->m_1_pointer > 2)
{
group_code = mpeg3bits_getbits(audio->astream, 5);
if(group_code > 26)
{
/* FIXME do proper block error handling */
// fprintf(stderr, "mpeg3audio_ac3_mantissa_get: Invalid mantissa 1 %d\n", group_code);
return 0;
}
mantissa_struct->m_1[0] = group_code / 9;
mantissa_struct->m_1[1] = (group_code % 9) / 3;
mantissa_struct->m_1[2] = (group_code % 9) % 3;
mantissa_struct->m_1_pointer = 0;
}
mantissa = mantissa_struct->m_1[mantissa_struct->m_1_pointer++];
mantissa = mpeg3_q_1[mantissa];
break;
case 2:
if(mantissa_struct->m_2_pointer > 2)
{
group_code = mpeg3bits_getbits(audio->astream, 7);
if(group_code > 124)
{
// fprintf(stderr, "mpeg3audio_ac3_mantissa_get: Invalid mantissa 2 %d\n", group_code);
return 0;
}
mantissa_struct->m_2[0] = group_code / 25;
mantissa_struct->m_2[1] = (group_code % 25) / 5;
mantissa_struct->m_2[2] = (group_code % 25) % 5;
mantissa_struct->m_2_pointer = 0;
}
mantissa = mantissa_struct->m_2[mantissa_struct->m_2_pointer++];
mantissa = mpeg3_q_2[mantissa];
break;
case 3:
mantissa = mpeg3bits_getbits(audio->astream, 3);
if(mantissa > 6)
{
// fprintf(stderr, "mpeg3audio_ac3_mantissa_get: Invalid mantissa 3 %d\n", group_code);
return 0;
}
mantissa = mpeg3_q_3[mantissa];
break;
case 4:
if(mantissa_struct->m_4_pointer > 1)
{
group_code = mpeg3bits_getbits(audio->astream, 7);
if(group_code > 120)
{
// fprintf(stderr, "mpeg3audio_ac3_mantissa_get: Invalid mantissa 4 %d\n", group_code);
return 0;
}
mantissa_struct->m_4[0] = group_code / 11;
mantissa_struct->m_4[1] = group_code % 11;
mantissa_struct->m_4_pointer = 0;
}
mantissa = mantissa_struct->m_4[mantissa_struct->m_4_pointer++];
mantissa = mpeg3_q_4[mantissa];
break;
case 5:
mantissa = mpeg3bits_getbits(audio->astream, 4);
if(mantissa > 14)
{
/* FIXME do proper block error handling */
// fprintf(stderr, "mpeg3audio_ac3_mantissa_get: Invalid mantissa 5 %d\n", group_code);
return 0;
}
mantissa = mpeg3_q_5[mantissa];
break;
default:
mantissa = mpeg3bits_getbits(audio->astream, mpeg3_qnttztab[bap]);
mantissa <<= 16 - mpeg3_qnttztab[bap];
}
return mantissa;
}
int mpeg3audio_II_step_two(mpeg3audio_t *audio, unsigned int *bit_alloc, float fraction[2][4][SBLIMIT], int *scale, int x1)
{
int i, j, k, ba, result = 0;
int channels = audio->channels;
int sblimit = audio->II_sblimit;
int jsbound = audio->jsbound;
struct al_table *alloc2, *alloc1 = audio->alloc;
unsigned int *bita = bit_alloc;
int d1, step, test;
for(i = 0; i < jsbound; i++, alloc1 += (1 << step))
{
step = alloc1->bits;
for(j = 0; j < channels; j++)
{
if(ba = *bita++)
{
k = (alloc2 = alloc1 + ba)->bits;
if((d1 = alloc2->d) < 0)
{
float cm = mpeg3_muls[k][scale[x1]];
fraction[j][0][i] = ((float)((int)mpeg3bits_getbits(audio->astream, k) + d1)) * cm;
fraction[j][1][i] = ((float)((int)mpeg3bits_getbits(audio->astream, k) + d1)) * cm;
fraction[j][2][i] = ((float)((int)mpeg3bits_getbits(audio->astream, k) + d1)) * cm;
}
else
{
static int *table[] =
{0, 0, 0, mpeg3_grp_3tab, 0, mpeg3_grp_5tab, 0, 0, 0, mpeg3_grp_9tab};
unsigned int idx, *tab, m = scale[x1];
idx = (unsigned int)mpeg3bits_getbits(audio->astream, k);
tab = (unsigned int*)(table[d1] + idx + idx + idx);
fraction[j][0][i] = mpeg3_muls[*tab++][m];
fraction[j][1][i] = mpeg3_muls[*tab++][m];
fraction[j][2][i] = mpeg3_muls[*tab][m];
}
scale += 3;
}
else
fraction[j][0][i] = fraction[j][1][i] = fraction[j][2][i] = 0.0;
}
}
for(i = jsbound; i < sblimit; i++, alloc1 += (1 << step))
{
step = alloc1->bits;
/* channel 1 and channel 2 bitalloc are the same */
bita++;
if((ba = *bita++))
{
k=(alloc2 = alloc1+ba)->bits;
if((d1 = alloc2->d) < 0)
{
float cm;
cm = mpeg3_muls[k][scale[x1 + 3]];
fraction[1][0][i] = (fraction[0][0][i] = (float)((int)mpeg3bits_getbits(audio->astream, k) + d1)) * cm;
fraction[1][1][i] = (fraction[0][1][i] = (float)((int)mpeg3bits_getbits(audio->astream, k) + d1)) * cm;
fraction[1][2][i] = (fraction[0][2][i] = (float)((int)mpeg3bits_getbits(audio->astream, k) + d1)) * cm;
cm = mpeg3_muls[k][scale[x1]];
fraction[0][0][i] *= cm;
fraction[0][1][i] *= cm;
fraction[0][2][i] *= cm;
}
else
{
static int *table[] = {0, 0, 0, mpeg3_grp_3tab, 0, mpeg3_grp_5tab, 0, 0, 0, mpeg3_grp_9tab};
unsigned int idx, *tab, m1, m2;
m1 = scale[x1];
m2 = scale[x1+3];
idx = (unsigned int)mpeg3bits_getbits(audio->astream, k);
tab = (unsigned int*)(table[d1] + idx + idx + idx);
fraction[0][0][i] = mpeg3_muls[*tab][m1];
fraction[1][0][i] = mpeg3_muls[*tab++][m2];
fraction[0][1][i] = mpeg3_muls[*tab][m1];
fraction[1][1][i] = mpeg3_muls[*tab++][m2];
fraction[0][2][i] = mpeg3_muls[*tab][m1];
fraction[1][2][i] = mpeg3_muls[*tab][m2];
}
scale += 6;
}
else
{
fraction[0][0][i] = fraction[0][1][i] = fraction[0][2][i] =
fraction[1][0][i] = fraction[1][1][i] = fraction[1][2][i] = 0.0;
}
/*
should we use individual scalefac for channel 2 or
is the current way the right one , where we just copy channel 1 to
channel 2 ??
The current 'strange' thing is, that we throw away the scalefac
values for the second channel ...!!
-> changed .. now we use the scalefac values of channel one !!
*/
}
if(sblimit > SBLIMIT) sblimit = SBLIMIT;
for(i = sblimit; i < SBLIMIT; i++)
for(j = 0; j < channels; j++)
fraction[j][0][i] = fraction[j][1][i] = fraction[j][2][i] = 0.0;
return result | mpeg3bits_error(audio->astream);
}
int mpeg3audio_II_step_one(mpeg3audio_t *audio, unsigned int *bit_alloc, int *scale)
{
int stereo = audio->channels - 1;
int sblimit = audio->II_sblimit;
int jsbound = audio->jsbound;
int sblimit2 = audio->II_sblimit << stereo;
struct al_table *alloc1 = audio->alloc;
int i, result = 0;
unsigned int *scfsi_buf = audio->layer2_scfsi_buf;
unsigned int *scfsi, *bita;
int sc, step;
bita = bit_alloc;
if(stereo)
{
/* Stereo */
for(i = jsbound;i ; i--, alloc1 += (1 << step))
{
*bita++ = (char)mpeg3bits_getbits(audio->astream, step = alloc1->bits);
*bita++ = (char)mpeg3bits_getbits(audio->astream, step);
}
for(i = sblimit-jsbound; i; i--, alloc1 += (1 << step))
{
bita[0] = (char)mpeg3bits_getbits(audio->astream, step = alloc1->bits);
bita[1] = bita[0];
bita += 2;
}
bita = bit_alloc;
scfsi = scfsi_buf;
for(i = sblimit2; i; i--)
if(*bita++) *scfsi++ = (char)mpeg3bits_getbits(audio->astream, 2);
}
else
{
/* mono */
for(i = sblimit; i; i--, alloc1 += (1 << step))
*bita++ = (char)mpeg3bits_getbits(audio->astream, step = alloc1->bits);
bita = bit_alloc;
scfsi = scfsi_buf;
for(i = sblimit; i; i--) if (*bita++) *scfsi++ = (char)mpeg3bits_getbits(audio->astream, 2);
}
bita = bit_alloc;
scfsi = scfsi_buf;
for(i = sblimit2; i; i--)
{
if(*bita++)
switch(*scfsi++)
{
case 0:
*scale++ = mpeg3bits_getbits(audio->astream, 6);
*scale++ = mpeg3bits_getbits(audio->astream, 6);
*scale++ = mpeg3bits_getbits(audio->astream, 6);
break;
case 1 :
*scale++ = sc = mpeg3bits_getbits(audio->astream, 6);
*scale++ = sc;
*scale++ = mpeg3bits_getbits(audio->astream, 6);
break;
case 2:
*scale++ = sc = mpeg3bits_getbits(audio->astream, 6);
*scale++ = sc;
*scale++ = sc;
break;
default: /* case 3 */
*scale++ = mpeg3bits_getbits(audio->astream, 6);
*scale++ = sc = mpeg3bits_getbits(audio->astream, 6);
*scale++ = sc;
break;
}
}
return result | 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);
}
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 0;
// return mpeg3bits_error(audio->astream);
}
