bool AudioDecoder::decodeNextFrame()
{
if(!_isSetup)
setupDecoder();
int got_frame = 0;
while( ! got_frame )
{
CodedData data;
bool nextPacketRead = _inputStream->readNextPacket( data );
if( ! nextPacketRead ) // error or end of file
data.clear();
int ret = avcodec_decode_audio4( &_inputStream->getAudioCodec().getAVCodecContext(), _frame, &got_frame, &data.getAVPacket() );
if( ! nextPacketRead && ret == 0 && got_frame == 0 ) // no frame could be decompressed
return false;
if( ret < 0 )
{
throw std::runtime_error( "an error occured during audio decoding" + getDescriptionFromErrorCode( ret ) );
}
}
return true;
}
void VDPAUDecoder::render(AVCodecContext* pContext, const AVFrame* pFrame)
{
vdpau_render_state* pRenderState = (vdpau_render_state*)pFrame->data[0];
if (m_VDPDecoder == VDP_INVALID_HANDLE) {
setupDecoder(pContext);
}
VdpStatus status = vdp_decoder_render(m_VDPDecoder, pRenderState->surface,
(VdpPictureInfo const*)&(pRenderState->info),
pRenderState->bitstream_buffers_used, pRenderState->bitstream_buffers);
AVG_ASSERT(status == VDP_STATUS_OK);
}
bool AudioPlaySdAac::setupMp4(void)
{
_ATOM ftyp = findMp4Atom("ftyp",0, false);
if (!ftyp.size)
return false; //no mp4/m4a file
//go through the boxes to find the interesting atoms:
uint32_t moov = findMp4Atom("moov", 0).position;
uint32_t trak = findMp4Atom("trak", moov + 8).position;
uint32_t mdia = findMp4Atom("mdia", trak + 8).position;
//determine duration:
uint32_t mdhd = findMp4Atom("mdhd", mdia + 8).position;
uint32_t timescale = fread32(mdhd + 8 + 0x0c);
duration = 1000.0 * ((float)fread32(mdhd + 8 + 0x10) / (float)timescale);
//MP4-data has no aac-frames, so we have to set the parameters by hand.
uint32_t minf = findMp4Atom("minf", mdia + 8).position;
uint32_t stbl = findMp4Atom("stbl", minf + 8).position;
//stsd sample description box: - infos to parametrize the decoder
_ATOM stsd = findMp4Atom("stsd", stbl + 8);
if (!stsd.size)
return false; //something is not ok
uint16_t channels = fread16(stsd.position + 8 + 0x20);
//uint16_t channels = 1;
//uint16_t bits = fread16(stsd.position + 8 + 0x22); //not used
uint16_t samplerate = fread32(stsd.position + 8 + 0x26);
setupDecoder(channels, samplerate, AAC_PROFILE_LC);
//stco - chunk offset atom:
uint32_t stco = findMp4Atom("stco", stbl + 8).position;
//number of chunks:
uint32_t nChunks = fread32(stco + 8 + 0x04);
//first entry from chunk table:
firstChunk = fread32(stco + 8 + 0x08);
//last entry from chunk table:
lastChunk = fread32(stco + 8 + 0x04 + nChunks * 4);
if (nChunks == 1) {
_ATOM mdat = findMp4Atom("mdat", 0);
lastChunk = mdat.size;
}
#if 0
Serial.print("mdhd duration=");
Serial.print(duration);
Serial.print(" ms, stsd: chan=");
Serial.print(channels);
Serial.print(" samplerate=");
Serial.print(samplerate);
Serial.print(" nChunks=");
Serial.print(nChunks);
Serial.print(" firstChunk=");
Serial.println(firstChunk, HEX);
Serial.print(" lastChunk=");
Serial.println(lastChunk, HEX);
#endif
return true;
}
