/**
* Loads the requested file into a MultiChannelBuffer. The buffer's channel count and buffer size
* will be adjusted to match the file.
*
* @shortdesc Loads the requested file into a MultiChannelBuffer.
* @example Advanced/loadFileIntoBuffer
* @param filename the file to load
* @param outBuffer the MultiChannelBuffer to fill with the file's audio samples
* @return the sample rate of audio samples in outBuffer, or 0 if the load failed.
* @related MultiChannelBuffer
*/
public float loadFileIntoBuffer(String filename, MultiChannelBuffer outBuffer) {
final int readBufferSize = 4096;
float sampleRate = 0;
AudioRecordingStream stream = mimp.getAudioRecordingStream(filename, readBufferSize, false);
if (stream != null) {
stream.open();
stream.play();
sampleRate = stream.getFormat().getSampleRate();
final int channelCount = stream.getFormat().getChannels();
// for reading the file in, in chunks.
MultiChannelBuffer readBuffer = new MultiChannelBuffer(channelCount, readBufferSize);
// make sure the out buffer is the correct size and type.
outBuffer.setChannelCount(channelCount);
// how many samples to read total
final long totalSampleCount = stream.getSampleFrameLength();
outBuffer.setBufferSize((int) totalSampleCount);
// now read in chunks.
long totalSamplesRead = 0;
while (totalSamplesRead < totalSampleCount) {
// is the remainder smaller than our buffer?
if (totalSampleCount - totalSamplesRead < readBufferSize) {
readBuffer.setBufferSize((int) (totalSampleCount - totalSamplesRead));
}
stream.read(readBuffer);
// copy data from one buffer to the other.
for (int i = 0; i < channelCount; ++i) {
// a faster way to do this would be nice.
for (int s = 0; s < readBuffer.getBufferSize(); ++s) {
outBuffer.setSample(i, (int) totalSamplesRead + s, readBuffer.getSample(i, s));
}
}
totalSamplesRead += readBuffer.getBufferSize();
}
stream.close();
} else {
debug("Unable to load an AudioRecordingStream for " + filename);
}
return sampleRate;
}
