public bool ReadChunk(ref IFrameDataSubset subset, int overrideChunkSize = 0)
{
if (_chunkReadIndex >= Left.Length)
{
return(false);
}
if (overrideChunkSize != 0)
{
_chunkReadSize = overrideChunkSize;
}
var readSize = _chunkReadSize;
var readIndex = _chunkReadIndex;
if (readIndex + readSize >= Left.Length)
{
readSize = Left.Length - readIndex;
}
_chunkReadIndex += readSize;
subset = new FrameDataSubset(Left, Right, readIndex, readSize);
return(true);
}
private float[] ConvertStereoToMono(IFrameDataSubset subset)
{
var outputIndex = 0;
var output = new float[subset.Length];
var offset = subset.Left.Offset;
for (var i = 0; i < subset.Length; i += 2)
{
output[outputIndex] = (subset.Left.Array[i + offset] + subset.Right.Array[i + offset]) / 2;
outputIndex++;
}
return output;
}
private float[] ConvertStereoToMono(IFrameDataSubset subset)
{
var outputIndex = 0;
var output = new float[subset.Length];
var offset = subset.Left.Offset;
for (var i = 0; i < subset.Length; i += 2)
{
output[outputIndex] = (subset.Left.Array[i + offset] + subset.Right.Array[i + offset]) / 2;
outputIndex++;
}
return(output);
}
public IFrameData MakeSummaryData(IFrameData input, int ratio)
{
var max = new List <float>();
input.BeginChunkyRead(ratio);
IFrameDataSubset subset = null;
while (input.ReadChunk(ref subset))
{
var maxmag = Math.Max(subset.Left.Max(), subset.Right.Max());
var minmag = Math.Min(subset.Left.Min(), subset.Right.Min());
max.Add(Math.Max(maxmag, Math.Abs(minmag)));
}
return(new FrameData(max.ToArray(), null, ratio));
}
public float[] DetectOnsets(IFrameData waveData, int samplesPerSecond, int sampleWindowSize, float sensitivity = 1.5f)
{
_onsetDetection = new OnsetDetection(sampleWindowSize, samplesPerSecond);
waveData.BeginChunkyRead(sampleWindowSize);
IFrameDataSubset subset = null;
while (waveData.ReadChunk(ref subset))
{
var mono = ConvertStereoToMono(subset);
_onsetDetection.AddFlux(mono);
}
var onsets = _onsetDetection.FindOnsets(sensitivity);
_onsetDetection.NormalizeOnsets(onsets, 0);
return(onsets);
}
public bool ReadChunk(ref IFrameDataSubset subset, int overrideChunkSize = 0)
{
if (_chunkReadIndex >= Left.Length) return false;
if (overrideChunkSize != 0)
{
_chunkReadSize = overrideChunkSize;
}
var readSize = _chunkReadSize;
var readIndex = _chunkReadIndex;
if (readIndex + readSize >= Left.Length)
{
readSize = Left.Length - readIndex;
}
_chunkReadIndex += readSize;
subset = new FrameDataSubset(Left, Right, readIndex, readSize);
return true;
}
