public void ReadIntoSpread(CancellationToken ct)
{
var channels = FAudioFile.WaveFormat.Channels;
long samples = (long)Math.Round(FAudioFile.TotalTime.TotalSeconds * FAudioFile.WaveFormat.SampleRate);
long startSample = 0;
if (Loop)
{
startSample = (long)(StartTime * FAudioFile.WaveFormat.SampleRate);
samples = (long)((EndTime - StartTime) * FAudioFile.WaveFormat.SampleRate);
}
var localSpreadCount = (int)Math.Min(SpreadCount, samples);
if (ToMono)
{
WaveFormSpread.SliceCount = 1;
WaveFormSpread[0] = new Spread <double>(localSpreadCount);
}
else
{
WaveFormSpread.SliceCount = channels;
for (int i = 0; i < channels; i++)
{
WaveFormSpread[i] = new Spread <double>(localSpreadCount);
}
}
int blockSize = (int)(samples / localSpreadCount);
FAudioFile.Position = startSample * channels * 4;
var bufferSize = blockSize * channels;
var buffer = new float[bufferSize];
var maxValue = 0.0f;
var outputBuffers = WaveFormSpread.Select(s => s.Stream.Buffer).ToArray();
for (int slice = 0; slice < localSpreadCount; slice++)
{
//read one interleaved block
var samplesRead = FAudioFile.Read(buffer, 0, bufferSize);
//split into channels and do the max
for (int channel = 0; channel < channels; channel++)
{
maxValue = MinValue;
for (int i = 0; i < samplesRead; i += channels)
{
maxValue = Math.Max(maxValue, Math.Abs(buffer[i + channel]));
}
if (ToMono)
{
outputBuffers[0][slice] = Math.Max(maxValue, outputBuffers[0][slice]);
}
else
{
outputBuffers[channel][slice] = maxValue;
}
ct.ThrowIfCancellationRequested();
}
}
}
protected override void FillBuffers(float[][] buffer, int offset, int sampleCount)
{
if (FAudioFile == null)
{
return;
}
var channels = FAudioFile.WaveFormat.Channels;
var blockAlign = FAudioFile.OriginalFileFormat.BlockAlign;
int samplesToRead;
if (Speed == 1.0)
{
samplesToRead = sampleCount * channels;
}
else
{
var desiredSamples = sampleCount * channels * Speed;
//ideal value
samplesToRead = (int)Math.Truncate(desiredSamples);
//can only read that much
var rem = samplesToRead % blockAlign;
samplesToRead -= rem;
FFractionalAccum += (desiredSamples - samplesToRead);
//gather error
//correct error
if (FFractionalAccum >= blockAlign)
{
samplesToRead += blockAlign;
FFractionalAccum -= blockAlign;
}
}
FFileBuffer = BufferHelpers.Ensure(FFileBuffer, samplesToRead);
int samplesRead = 0;
if (FPlay && samplesToRead > 0)
{
samplesRead = FAudioFile.Read(FFileBuffer, offset * channels, samplesToRead);
if (samplesRead == 0)
{
if (FLoop)
{
FAudioFile.CurrentTime = LoopStartTime;
FRunToEndBeforeLooping = false;
samplesRead = FAudioFile.Read(FFileBuffer, offset * channels, samplesToRead);
}
else
{
samplesRead = FFileBuffer.ReadSilence(offset * channels, samplesToRead);
}
if (FLoop && FAudioFile.CurrentTime >= LoopEndTime)
{
FAudioFile.CurrentTime = LoopStartTime;
FRunToEndBeforeLooping = false;
//bytesread = FAudioFile.Read(FFileBuffer, offset*channels, samplesToRead);
}
}
if (Speed == 1.0)
{
//copy to output buffers
for (int i = 0; i < channels; i++)
{
for (int j = 0; j < sampleCount; j++)
{
buffer[i][j] = FFileBuffer[i + j * channels];
}
}
}
else //resample
{
FResampler.ResampleDeinterleave(FFileBuffer, buffer, samplesToRead / channels, sampleCount, channels);
}
}
else //silence
{
for (int i = 0; i < channels; i++)
{
buffer[i].ReadSilence(offset, sampleCount);
}
}
}