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#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include "a52.h"
#include "mpeg3private.h"
#include "mpeg3protos.h"
#include <string.h>
mpeg3_ac3_t* mpeg3_new_ac3()
{
mpeg3_ac3_t *result = calloc(1, sizeof(mpeg3_ac3_t));
result->stream = mpeg3bits_new_stream(0, 0);
result->state = a52_init(0);
result->output = a52_samples(result->state);
return result;
}
void mpeg3_delete_ac3(mpeg3_ac3_t *audio)
{
mpeg3bits_delete_stream(audio->stream);
a52_free(audio->state);
free(audio);
}
/* Return 1 if it isn't an AC3 header */
int mpeg3_ac3_check(unsigned char *header)
{
int flags, samplerate, bitrate;
return !a52_syncinfo(header,
&flags,
&samplerate,
&bitrate);
}
/* Decode AC3 header */
int mpeg3_ac3_header(mpeg3_ac3_t *audio, unsigned char *header)
{
int result = 0;
audio->flags = 0;
//printf("mpeg3_ac3_header %02x%02x%02x%02x%02x%02x%02x%02x\n", header[0], header[1], header[2], header[3], header[4], header[5], header[6], header[7]);
result = a52_syncinfo(header,
&audio->flags,
&audio->samplerate,
&audio->bitrate);
if(result)
{
//printf("%d\n", result);
audio->framesize = result;
audio->channels = 0;
if(audio->flags & A52_LFE)
audio->channels++;
/*
* printf("mpeg3_ac3_header %08x %08x\n",
* audio->flags & A52_LFE,
* audio->flags & A52_CHANNEL_MASK);
*/
switch(audio->flags & A52_CHANNEL_MASK)
{
case A52_CHANNEL:
audio->channels++;
break;
case A52_MONO:
audio->channels++;
break;
case A52_STEREO:
audio->channels += 2;
break;
case A52_3F:
audio->channels += 3;
break;
case A52_2F1R:
audio->channels += 3;
break;
case A52_3F1R:
audio->channels += 4;
break;
case A52_2F2R:
audio->channels += 4;
break;
case A52_3F2R:
audio->channels += 5;
break;
case A52_DOLBY:
audio->channels += 2;
break;
default:
printf("mpeg3_ac3_header: unknown channel code: %x\n", audio->flags & A52_CHANNEL_MASK);
break;
}
}
//printf("mpeg3_ac3_header 1 %d\n", audio->channels);
return result;
}
int mpeg3audio_doac3(mpeg3_ac3_t *audio,
char *frame,
int frame_size,
float **output,
int render)
{
int output_position = 0;
sample_t level = 1;
int i, j, k, l;
//printf("mpeg3audio_doac3 1\n");
a52_frame(audio->state,
frame,
&audio->flags,
&level,
0);
//printf("mpeg3audio_doac3 2\n");
a52_dynrng(audio->state, NULL, NULL);
//printf("mpeg3audio_doac3 3\n");
for(i = 0; i < 6; i++)
{
if(!a52_block(audio->state))
{
l = 0;
if(render)
{
// Remap the channels to conform to encoders.
for(j = 0; j < audio->channels; j++)
{
int dst_channel = j;
// Make LFE last channel.
// Shift all other channels down 1.
if((audio->flags & A52_LFE))
{
if(j == 0)
dst_channel = audio->channels - 1;
else
dst_channel--;
}
// Swap front left and center for certain configurations
switch(audio->flags & A52_CHANNEL_MASK)
{
case A52_3F:
case A52_3F1R:
case A52_3F2R:
if(dst_channel == 0) dst_channel = 1;
else
if(dst_channel == 1) dst_channel = 0;
break;
}
for(k = 0; k < 256; k++)
{
output[dst_channel][output_position + k] = ((sample_t*)audio->output)[l];
l++;
}
}
}
output_position += 256;
}
}
return output_position;
}
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