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_synth_mono(mpeg3audio_t *audio, float *bandPtr, float *samples, int *pnt)
{
float *samples_tmp = audio->synth_mono_buff;
float *tmp1 = samples_tmp;
int i, ret;
int pnt1 = 0;
ret = mpeg3audio_synth_stereo(audio, bandPtr, 0, samples_tmp, &pnt1);
samples += *pnt;
for(i = 0; i < 32; i++)
{
*samples = *tmp1;
samples++;
tmp1 += 2;
}
*pnt += 32;
return ret;
}
