IFrame* AudioFrameBuffer::getFrame(const size_t size)
{
LOG_DEBUG("Get a " << size << " bytes frame from a " << _totalDataSize << " bytes frame buffer");
IFrame* next = _frameQueue.front();
const size_t nextFrameSize = next->getDataSize();
// If no expected size, or if the expected size equals the front frame of the queue (with no offset)
if(size == 0 || (size == nextFrameSize && _positionInFrontFrame == 0))
{
// Directly return the front frame of the queue
_totalDataSize -= nextFrameSize;
popFrame();
return next;
}
// Create a new frame
AudioFrame* newAudioFrame = new AudioFrame(_audioFrameDesc, false);
const size_t expectedNbSamples = size / (newAudioFrame->getNbChannels() * newAudioFrame->getBytesPerSample());
newAudioFrame->setNbSamplesPerChannel(expectedNbSamples);
newAudioFrame->allocateData();
// Concatenate frames data
size_t extractedDataSize = 0;
unsigned char* outputData = new unsigned char[size];
while(extractedDataSize != size && _frameQueue.size() != 0)
{
// Get the front frame from queue
next = _frameQueue.front();
size_t remainingDataInFrontFrame = next->getDataSize() - _positionInFrontFrame;
// Compute the data size to get from the frame
size_t dataToGet = size - extractedDataSize;
if(dataToGet > remainingDataInFrontFrame)
dataToGet = remainingDataInFrontFrame;
// Copy the data from the frame to temporal buffer
for(size_t i = 0; i < dataToGet; i++)
outputData[extractedDataSize++] = next->getData()[0][_positionInFrontFrame + i];
if(dataToGet < remainingDataInFrontFrame)
{
// Set new position into front frame
_positionInFrontFrame += dataToGet;
}
else
{
// The whole front frame has been read, so pop it from queue
popFrame();
_positionInFrontFrame = 0;
}
}
_totalDataSize -= extractedDataSize;
newAudioFrame->assignBuffer(outputData);
return newAudioFrame;
}
