/// <summary>
/// Streams audio into a floating point sample buffer.
/// </summary>
/// <param name="unityBuffer"></param>
/// <param name="intermediateBuffer">A PCM sample buffer to act as an intermediary between the raw audio stream and Unity.</param>
/// <param name="audioStream"></param>
/// <returns>Returns the number of samples that were read from the stream.</returns>
public static int FillUnityStreamBuffer(float[] unityBuffer, PCMAudioBuffer intermediateBuffer, MP3StreamReader audioStream)
{
if (audioStream.isDoneStreaming)
{
// Fill the Unity sample buffer with zeros.
Array.Clear(unityBuffer, 0, unityBuffer.Length);
return(0);
}
int totalSampleFramesToRead = unityBuffer.Length / audioStream.channelCount;
int sampleFramesRead = 0;
while (sampleFramesRead < totalSampleFramesToRead)
{
// Read some sample frames.
int sampleFramesLeftToRead = totalSampleFramesToRead - sampleFramesRead;
int sampleFramesReturned = audioStream.ReadSampleFrames(intermediateBuffer.data, 0, Math.Min(sampleFramesLeftToRead, intermediateBuffer.sampleFrameCount));
if (sampleFramesReturned > 0)
{
// Convert the read samples to floats copy them to the output buffer.
intermediateBuffer.ToFloatArray(unityBuffer, sampleFramesRead, sampleFramesReturned);
sampleFramesRead += sampleFramesReturned;
}
else
{
// Fill the rest of the Unity sample buffer with zeros.
int samplesRead = sampleFramesRead * audioStream.channelCount;
Array.Clear(unityBuffer, samplesRead, unityBuffer.Length - samplesRead);
break;
}
}
return(sampleFramesRead * audioStream.channelCount);
}
// TODO: Handle exceptions
public static PCMAudioBuffer ReadMP3(string filePath)
{
using (MP3StreamReader audioStream = new MP3StreamReader(filePath))
{
var audioData = new List <byte>(2 * (int)audioStream.compressedStreamLengthInBytes); // Allocate enough space for a 50% compression ratio.
int streamBufferSizeInSampleFrames = 16384;
var streamBuffer = new byte[SampleFramesToBytes(streamBufferSizeInSampleFrames, audioStream.channelCount, audioStream.bitDepth)];
do
{
int sampleFramesRead = audioStream.ReadSampleFrames(streamBuffer, 0, streamBufferSizeInSampleFrames);
if (sampleFramesRead > 0)
{
int bytesRead = SampleFramesToBytes(sampleFramesRead, audioStream.channelCount, audioStream.bitDepth);
audioData.AddRange(new ArrayRange <byte>(streamBuffer, 0, bytesRead));
}
} while (!audioStream.isDoneStreaming);
return(new PCMAudioBuffer(audioStream.channelCount, audioStream.bitDepth, audioStream.samplingRate, audioData.ToArray()));
}
}
