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#include "mpeg3audio.h"
#include "../libmpeg3.h"
#include "../mpeg3protos.h"
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_do_pcm(mpeg3audio_t *audio)
{
int i, j, k;
MPEG3_INT16 sample;
int frame_samples = (audio->framesize - 3) / audio->channels / 2;
if(mpeg3bits_read_buffer(audio->astream, audio->ac3_buffer, frame_samples * audio->channels * 2))
return 1;
/* Need more room */
if(audio->pcm_point / audio->channels >= audio->pcm_allocated - MPEG3AUDIO_PADDING * audio->channels)
{
mpeg3audio_replace_buffer(audio, audio->pcm_allocated + MPEG3AUDIO_PADDING * audio->channels);
}
k = 0;
for(i = 0; i < frame_samples; i++)
{
for(j = 0; j < audio->channels; j++)
{
sample = ((MPEG3_INT16)(audio->ac3_buffer[k++])) << 8;
sample |= audio->ac3_buffer[k++];
audio->pcm_sample[audio->pcm_point + i * audio->channels + j] =
(mpeg3_real_t)sample / 32767;
}
}
audio->pcm_point += frame_samples * audio->channels;
return 0;
}
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