/// <summary>
/// Engages the specified source floats. This doc was autogenerated so it's weird.
/// </summary>
/// <param name="sourceFloats">The source floats.</param>
/// <param name="sourceLength">Length of the source -- how many floats to use from the provided buffer.</param>
/// <param name="resampledResult">The resampled result.</param>
/// <param name="sampleRateIn">The sample rate in.</param>
/// <param name="sampleRateOut">The sample rate out.</param>
/// <returns>
/// the number of samples processed
/// </returns>
public int Engage(float[] sourceFloats,
int sourceLength,
out float[] resampledResult,
int sampleRateIn,
int sampleRateOut)
{
// The resampler code is very delicate. I don't recommend messing with it unless you have a week to
// spend on it.
// See https://gist.github.com/markheath/dc41131fefb84b93b041f1dde8a08209 for more info
_resampler.SetMode(false, 0, false);
_resampler.SetFilterParms();
_resampler.SetRates(sampleRateIn, sampleRateOut);
_resampler.SetFeedMode(true); // input driven
float[] inData;
int inBufferOffset;
int inputFrameCount = sourceLength / _channels;
int framesExpected = _resampler.ResamplePrepare(inputFrameCount, _channels, out inData, out inBufferOffset);
// Feed the samples into the resampler's byte array.
Array.Copy(sourceFloats, 0, inData, inBufferOffset, framesExpected * _channels);
var ratio = (double)sampleRateIn / sampleRateOut;
double expected = (double)framesExpected * _channels / ratio;
// round upward to nearest complete frame to prevent data loss
int roundedSamples = (int)Math.Ceiling(expected / _channels) * _channels;
resampledResult = new float[roundedSamples];
// the return value is the Inverse of what would actually be helpful
int framesProcessed = _resampler.ResampleOut(resampledResult, 0, framesExpected, roundedSamples, _channels);
return(framesProcessed * 2);
}
/// <summary>
/// Constructs a new resampler
/// </summary>
/// <param name="source">Source to resample</param>
/// <param name="newSampleRate">Desired output sample rate</param>
public WdlResamplingSampleProvider(ISampleProvider source, int newSampleRate)
{
channels = source.WaveFormat.Channels;
outFormat = WaveFormat.CreateIeeeFloatWaveFormat(newSampleRate, channels);
this.source = source;
resampler = new WdlResampler();
resampler.SetMode(true, 2, false);
resampler.SetFilterParms();
resampler.SetFeedMode(false); // output driven
resampler.SetRates(source.WaveFormat.SampleRate, newSampleRate);
}
public Resampler(ISampleSource source, IRateProvider rate)
{
_source = source;
_rate = rate;
AudioSettings.OnAudioConfigurationChanged += OnAudioConfigurationChanged;
OnAudioConfigurationChanged(false);
_resampler = new WdlResampler();
_resampler.SetMode(true, 2, false);
_resampler.SetFilterParms();
_resampler.SetFeedMode(false);
}
public Resampler([NotNull] ISampleProvider source, int newSampleRate)
{
_source = source;
_format = new WaveFormat(source.WaveFormat.Channels, newSampleRate);
if (source.WaveFormat.SampleRate != newSampleRate)
{
_resampler = new WdlResampler();
_resampler.SetMode(true, 2, false);
_resampler.SetFilterParms();
_resampler.SetFeedMode(false); // output driven
_resampler.SetRates(source.WaveFormat.SampleRate, newSampleRate);
}
}
public bool Read(ArraySegment <float> samples)
{
var inFormat = _source.WaveFormat;
var outFormat = _outputFormat;
if (outFormat.SampleRate == inFormat.SampleRate)
{
return(_source.Read(samples));
}
if (_resampler == null || outFormat.SampleRate != (int)_resampler.OutputSampleRate)
{
Log.Debug("Initializing resampler to resample {0}Hz source to {1}Hz output", inFormat.SampleRate, outFormat.SampleRate);
_resampler = new WdlResampler();
_resampler.SetMode(true, 2, false);
_resampler.SetFilterParms();
_resampler.SetFeedMode(false); // output driven
_resampler.SetRates(inFormat.SampleRate, outFormat.SampleRate);
}
var channels = inFormat.Channels;
// prepare buffers
float[] inBuffer;
int inBufferOffset;
var samplesPerChannelRequested = samples.Count / channels;
var samplesPerChannelRequired = _resampler.ResamplePrepare(samplesPerChannelRequested, channels, out inBuffer, out inBufferOffset);
var sourceBuffer = new ArraySegment <float>(inBuffer, inBufferOffset, samplesPerChannelRequired * channels);
// read source
var complete = _source.Read(sourceBuffer);
// resample
Log.Trace("Resampling {0}Hz -> {1}Hz", inFormat.SampleRate, outFormat.SampleRate);
_resampler.ResampleOut(samples.Array, samples.Offset, samplesPerChannelRequired, samplesPerChannelRequested, channels);
return(complete);
}
