/*
* The poll function. Checks if more data is needed, and decodes/plays if
* needed.
*/
int _apeg_audio_poll(APEG_LAYER *layer)
{
#ifndef DISABLE_MPEG_AUDIO
struct reader *rd = &(layer->audio.rd);
struct frame *fr = &(layer->audio.fr);
struct mpstr *mp = &(layer->audio.mp);
int ret = APEG_OK;
#endif
if(layer->multiple <= 0.0f)
return APEG_OK;
if(layer->stream.flags & APEG_VORBIS_AUDIO)
return alvorbis_update(layer);
#ifdef DISABLE_MPEG_AUDIO
return APEG_ERROR;
#else
// Check if we actually need more data yet
while(!rd->eof && layer->audio.pcm.point < layer->audio.bufsize)
{
// Make sure we're not still in the process of decoding the previous
// frame
if(mp->return_later)
{
decode_frame(layer, fr, mp);
continue;
}
ret = read_frame(layer, fr);
if(ret != ALMPA_OK)
{
// Stream ended, but check if there's still audio in the buffer
if(!layer->audio.pcm.point)
return ret;
ret = APEG_OK;
break;
}
/* TODO: for fast forwarding */
/* if(stream->frame > layer->audio.frame)
{
if(fr->lay == 3)
set_pointer(mp, fr->sideInfoSize, 512);
goto do_again;
}*/
// Check for header change. This works, but it will introduce a jump
// if the frequency/channel count changes.
if(!layer->audio.inited)
{
int old_rate = layer->stream.audio.freq;
int old_channels = layer->stream.audio.channels;
int newrate = freqs[fr->sampling_frequency] >>
layer->stream.audio.down_sample;
layer->stream.audio.channels = (layer->stream.audio.down_channel?1:
fr->stereo);
layer->stream.audio.freq = newrate;
layer->stream.audio.layer = fr->lay;
layer->stream.audio.kbps = tabsel_123[fr->lsf][fr->lay-1][fr->bitrate_index];
fr->down_sample_sblimit = SBLIMIT>>layer->stream.audio.down_sample;
if(layer->stream.audio.freq != old_rate ||
layer->stream.audio.channels != old_channels)
{
if(fr->lay == 3)
init_layer3(layer->stream.audio.down_sample);
if(_apeg_audio_reset_parameters(layer) != APEG_OK)
return APEG_ERROR;
}
layer->audio.inited = TRUE;
}
++(layer->audio.frame);
decode_frame(layer, fr, mp);
}
/* Opens the Ogg stream, searching for and initializing Theora and Vorbis media
*/
int alogg_open(APEG_LAYER *layer)
{
ALOGG_INFO *info;
int vok = 0, aok = 0;
int flag, cs, size;
info = calloc(1, sizeof(ALOGG_INFO));
if(!info)
return APEG_ERROR;
LOCK_DATA(info, sizeof(ALOGG_INFO));
ogg_sync_init(&info->osync);
theora_comment_init(&info->tcomment);
theora_info_init(&info->tinfo);
vorbis_info_init(&info->vinfo);
vorbis_comment_init(&info->vcomment);
flag = FALSE;
while(!flag)
{
int ret = buffer_data(layer, info);
if(ret == 0)
break;
while(ogg_sync_pageout(&info->osync, &info->opage) > 0)
{
ogg_stream_state test;
/* is this a mandated initial header? If not, stop parsing */
if(!ogg_page_bos(&info->opage))
{
if(vok > 0)
ogg_stream_pagein(&info->ostream[0], &info->opage);
if(aok > 0)
ogg_stream_pagein(&info->ostream[1], &info->opage);
flag = TRUE;
break;
}
ogg_stream_init(&test, ogg_page_serialno(&info->opage));
ogg_stream_pagein(&test, &info->opage);
ogg_stream_packetout(&test, &info->opkt);
/* identify the codec: try theora */
if(!vok && theora_decode_header(&info->tinfo, &info->tcomment,
&info->opkt) >= 0)
{
/* it is theora */
if(!_apeg_ignore_video)
{
memcpy(&info->ostream[0], &test, sizeof(test));
vok = 1;
}
else
ogg_stream_clear(&test);
}
else if(!aok && vorbis_synthesis_headerin(&info->vinfo,
&info->vcomment, &info->opkt) >= 0)
{
/* it is vorbis */
if(!_apeg_ignore_audio)
{
memcpy(&info->ostream[1], &test, sizeof(test));
aok = 1;
}
else
ogg_stream_clear(&test);
}
/* whatever it is, we don't care about it */
else
ogg_stream_clear(&test);
}
/* fall through to non-bos page parsing */
}
/* look for further theora headers */
while((vok > 0 && vok < 3) || (aok > 0 && aok < 3))
{
int ret;
// Get the last two of three Theora headers
while(vok > 0 && vok < 3 &&
(ret = ogg_stream_packetout(&info->ostream[0], &info->opkt)))
{
if(ret < 0)
goto error;
if(theora_decode_header(&info->tinfo, &info->tcomment, &info->opkt))
goto error;
++vok;
}
// Get the last two of three Vorbis headers
while(aok > 0 && aok < 3 &&
(ret = ogg_stream_packetout(&info->ostream[1], &info->opkt)))
{
if(ret < 0)
goto error;
if(vorbis_synthesis_headerin(&info->vinfo, &info->vcomment,
&info->opkt))
goto error;
++aok;
}
if(ogg_sync_pageout(&info->osync, &info->opage) <= 0)
{
/* need more data */
if(buffer_data(layer, info) == 0)
break;
}
else
{
if(vok > 0)
ogg_stream_pagein(&info->ostream[0], &info->opage);
if(aok > 0)
ogg_stream_pagein(&info->ostream[1], &info->opage);
}
}
// Neither Vorbis or Theora fully initialized. Error.
if(vok != 3 && aok != 3)
goto error;
layer->ogg_info = info;
if(aok == 3)
{
vorbis_synthesis_init(&info->vdsp, &info->vinfo);
vorbis_block_init(&info->vdsp, &info->vblock);
if(info->vinfo.channels == 1)
layer->stream.audio.down_channel = FALSE;
layer->stream.audio.channels = info->vinfo.channels;
layer->stream.audio.freq = info->vinfo.rate >>
layer->stream.audio.down_sample;
if(_apeg_audio_reset_parameters(layer) != APEG_OK)
{
vorbis_block_clear(&info->vblock);
vorbis_dsp_clear(&info->vdsp);
goto error;
}
// layer->audio.inited = TRUE;
layer->stream.flags |= APEG_VORBIS_AUDIO;
}