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#include "mpeg3private.h"
#include "mpeg3protos.h"
#include <stdlib.h>
mpeg3_pcm_t* mpeg3_new_pcm()
{
mpeg3_pcm_t *result = calloc(1, sizeof(mpeg3_pcm_t));
return result;
}
void mpeg3_delete_pcm(mpeg3_pcm_t *audio)
{
free(audio);
}
int mpeg3_pcm_check(unsigned char *header)
{
if(header[0] == ((MPEG3_PCM_START_CODE & 0xff000000) >> 24) &&
header[1] == ((MPEG3_PCM_START_CODE & 0xff0000) >> 16) &&
header[2] == ((MPEG3_PCM_START_CODE & 0xff00) >> 8) &&
header[3] == (MPEG3_PCM_START_CODE & 0xff))
return 0;
else
return 1;
}
int mpeg3_pcm_header(mpeg3_pcm_t *audio, unsigned char *data)
{
if(mpeg3_pcm_check(data)) return 0;
/* Custom header generated by the demuxer */
audio->samplerate = *(int32_t*)(data + 4);
audio->bits = *(int32_t*)(data + 8);
audio->channels = *(int32_t*)(data + 12);
audio->framesize = *(int32_t*)(data + 16);
return audio->framesize;
}
int mpeg3audio_dopcm(mpeg3_pcm_t *audio,
char *frame,
int frame_size,
float **output,
int render)
{
int bytes_per_sample = audio->bits / 8 * audio->channels;
int output_size = (frame_size - PCM_HEADERSIZE) / bytes_per_sample;
int i, j;
//printf("mpeg3audio_dopcm 2 %d\n", frame_size);
if(render)
{
for(i = 0; i < audio->channels; i++)
{
//printf("mpeg3audio_dopcm 3\n");
float *output_channel = output[i];
//printf("mpeg3audio_dopcm 4\n");
switch(audio->bits)
{
case 16:
{
//printf("mpeg3audio_dopcm 5\n");
unsigned char *input = frame +
PCM_HEADERSIZE +
audio->bits / 8 * i;
int16_t sample;
//printf("mpeg3audio_dopcm 6\n");
for(j = 0; j < output_size; j++)
{
sample = ((int16_t)(input[0])) << 8;
sample |= input[1];
*output_channel = (float)sample / 32767.0;
input += bytes_per_sample;
output_channel++;
}
//printf("mpeg3audio_dopcm 7\n");
}
break;
}
}
}
/*
* printf("mpeg3audio_dopcm 2 %02x%02x%02x%02x\n",
* *(unsigned char*)(frame + PCM_HEADERSIZE + 0),
* *(unsigned char*)(frame + PCM_HEADERSIZE + 1),
* *(unsigned char*)(frame + PCM_HEADERSIZE + 2),
* *(unsigned char*)(frame + PCM_HEADERSIZE + 3));
*/
return output_size;
}
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