int __stdcall ac3_decode_frame(ac3_state *state)
{
uint_32 i;
int j;
int error_flag=0;
// debug(DAC3,"(decode_frame) begin frame %d\n",state->frame_count);
//find a syncframe and parse
parse_syncinfo(&state->syncinfo,&error_flag,state);
if(error_flag)
{
// debug(DAC3," -- fail after parse_syncinfo\n");
goto error;
}
state->frame_count++;
state->sampling_rate = state->syncinfo.sampling_rate;
parse_bsi(&state->bsi,state);
stats_print_banner(&state->syncinfo,&state->bsi,state);
for(i=0; i < 6; i++)
{
//Initialize freq/time sample storage
memset(state->samples,0,sizeof(float) * 256 * (state->bsi.nfchans + state->bsi.lfeon));
// Extract most of the audblk info from the bitstream
// (minus the mantissas
parse_audblk(&state->bsi,&state->audblk,state);
// Take the differential exponent data and turn it into
// absolute exponents
exponent_unpack(&state->bsi,&state->audblk,&error_flag,state);
if(error_flag)
{
// debug(DAC3," -- fail after exponent_unpack\n");
goto error;
}
// Figure out how many bits per mantissa
bit_allocate(state->syncinfo.fscod,&state->bsi,&state->audblk,state);
// Extract the mantissas from the stream and
// generate floating point frequency coefficients
coeff_unpack(&state->bsi,&state->audblk,state->samples,&error_flag,state);
if(error_flag)
{
// debug(DAC3," -- fail after coeff_unpack\n");
goto error;
}
if(state->bsi.acmod == 0x2)
{
rematrix(&state->audblk,state->samples);
}
// Convert the frequency samples into time samples
imdct(&state->bsi,&state->audblk,state->samples);
// Downmix into the requested number of channels
// and convert floating point to sint_16
for(j=0;j<256;j++)
{
state->left[i*256+j]=(sint_16)(state->samples[0][j]*32767.0f);
state->center[i*256+j]=(sint_16)(state->samples[1][j]*32767.0f);
state->right[i*256+j]=(sint_16)(state->samples[2][j]*32767.0f);
state->sleft[i*256+j]=(sint_16)(state->samples[3][j]*32767.0f);
state->sright[i*256+j]=(sint_16)(state->samples[4][j]*32767.0f);
state->subwoofer[i*256+j]=(sint_16)(state->samples[5][j]*32767.0f);
}
sanity_check(&state->syncinfo,&state->bsi,&state->audblk,&error_flag,state);
if(error_flag)
{
// debug(DAC3," -- sanity check fail\n");
goto error;
}
}
parse_auxdata(&state->syncinfo,state);
return 0;
error:
// debug(DAC3," -- FRAME ZEROED\n");
return -1;
}
uint_32 ac3_decode_data(uint_8 *data_start, uint_32 length, uint_32 *start, short *audio_buf_ptr)
{
uint_8 *data_initial = data_start;
uint_8 *data_end = data_start + length;
uint_32 i, j = *start*2;
int ret;
// error_flag = buffer_size = 0;
// syncinfo.syncword = 0xffff;
// printf("In ac3_decode_data\n");
while ((ret = decode_buffer_syncframe(&syncinfo, &data_start, data_end)) > 0)
{
if (error_flag)
{
#ifdef _WIN32
SetDlgItemText(hDlg, IDC_INFO, "A.E.!");
#else
printf("A.E.!\n");
#endif
ZeroMemory(s16_samples, sizeof(sint_16) * 256 * 2 * 6);
error_flag = 0;
continue;
}
parse_bsi(&bsi);
for (i=0; i<6; i++)
{
ZeroMemory(samples, sizeof(double) * 256 * (bsi.nfchans + bsi.lfeon));
parse_audblk(&bsi, &audblk);
exponent_unpack(&bsi, &audblk);
if (error_flag)
goto error;
bit_allocate(syncinfo.fscod, &bsi, &audblk);
coeff_unpack(&bsi, &audblk, samples);
if (error_flag)
goto error;
if (bsi.acmod == 0x2)
rematrix(&audblk, samples);
imdct(&bsi, &audblk, samples);
downmix(&audblk, &bsi, samples, &s16_samples[i * 512]);
sanity_check(&bsi, &audblk);
if (error_flag)
goto error;
}
memcpy(&audio_buf_ptr[(*start)/2], s16_samples, 6144);
*start += 6144;
error:
;
}
// if (ret == -1)
// return(-1);
sampling_rate=syncinfo.sampling_rate;
AC3_byterate = syncinfo.bit_rate/8*1000;
/* if (Decision_Flag || (!SRC_Flag && Normalization_Flag))
for (i=(j>>1); i<(start>>1); i++)
if (Sound_Max < abs(ptrAC3Dec_Buffer[i]))
{
Sound_Max = abs(ptrAC3Dec_Buffer[i]);
if (Decision_Flag && Sound_Max > Norm_Ratio)
{
sprintf(szBuffer, "%.2f", 327.68 * Norm_Ratio / Sound_Max);
SetDlgItemText(hDlg, IDC_INFO, szBuffer);
}
}
*/
// return (data_end - data_initial);
return (data_start - data_initial);
}
int AC3_SampleConvert(sint_16 *pPcmData, uint_32 *pnPcmDataLen, uint_8* pAc3Buf, uint_32 nAc3DataLen)
{
int i;
bitstream_t *bs;
long SampleRate = 0; /* bitstream sample-rate */
uint_32 cbErrors = 0; /* bitstream error count returned by decode_sanity_check() */
uint_32 cbMantErrors, cbExpErrors; /* error counters for mantissa & exponent unpacking errors */
bsi_t bsi_blank = {0};
static audblk_t audblk_blank = {0};
bs = bitstream_open(pAc3Buf, pAc3Buf+nAc3DataLen);
imdct_init();
/* initialize decoder and counter variables */
(bsi) = bsi_blank;
(audblk) = audblk_blank;
decode_sanity_check_init();
bsi_blank = bsi;
audblk_blank = audblk;
cbErrors = 0;
audblk = audblk_blank; /* clear out audioblock */
if(!(decode_resync(bs)))
{
return 0;
}
bsi = bsi_blank; /* v0.04 wipe bsi clear, not really necessary */
parse_syncinfo(&syncinfo,bs);
parse_bsi(&bsi,bs);
switch (syncinfo.fscod)
{
case 2:
SampleRate = 32000;
break;
case 1:
SampleRate = 44100;
break;
case 0:
SampleRate = 48000;
break;
default:
return 0;
}
/* reset bitstream error counters */
cbErrors =
cbExpErrors =
cbMantErrors = 0;
memset(pPcmData, 0, BUFFER_SIZE1*2);
*pnPcmDataLen = 0;
for(i=0; i < 6; i++)
{
long buf_offset;
parse_audblk(&bsi,&audblk,bs,i); // CPU time 10%
cbExpErrors = exponent_unpack(&bsi,&audblk);
if(cbExpErrors > 0)
{
return 0;
cbExpErrors =0;
}
bit_allocate(syncinfo.fscod,&bsi,&audblk); // CPU TIME 1.2%
if ( bsi.nfchans > 6 )
{
bsi.nfchans = 0;
return 0;//(LPBYTE) out_buf;
}
cbMantErrors = mantissa_unpack(&bsi,&audblk,bs); // CPU TIME 62.0%
if( cbMantErrors > 0)
{
return 0;
cbMantErrors = 0;
}
uncouple(&bsi,&audblk,&stream_coeffs); // CPU TIME 1.7%
if(bsi.acmod == 0x2)
rematrix(&audblk,&stream_coeffs); // CPU TIME 0.1%
imdct(&bsi,&audblk,&stream_coeffs,&stream_samples); // CPU TIME 11.2%
buf_offset = i * 512;
downmix( &stream_samples, pPcmData+buf_offset, &bsi, 0 );
} /* endfor ( i = 0 ... ) */
*pnPcmDataLen = 6*512*2;
cbErrors = decode_sanity_check();
if(cbErrors > 0)
{
return 0;
}
parse_auxdata(&syncinfo,bs); // CPU TIME 2.0%
if(!crc_validate())
{
return 0;
}
return 1;
}
