public VariableSpeedSampleProvider(ISampleProvider sourceProvider, int readDurationMilliseconds,
SoundTouchProfile soundTouchProfile)
{
_soundTouch = new SoundTouch.SoundTouch();
// explore what the default values are before we change them:
//Debug.WriteLine(String.Format("SoundTouch Version {0}", soundTouch.VersionString));
//Debug.WriteLine("Use QuickSeek: {0}", soundTouch.GetUseQuickSeek());
//Debug.WriteLine("Use AntiAliasing: {0}", soundTouch.GetUseAntiAliasing());
SetSoundTouchProfile(soundTouchProfile);
_sourceProvider = sourceProvider;
_soundTouch.SetSampleRate(WaveFormat.SampleRate);
_channelCount = WaveFormat.Channels;
_soundTouch.SetChannels(_channelCount);
_sourceReadBuffer = new float[(WaveFormat.SampleRate * _channelCount * (long)readDurationMilliseconds) / 1000];
_soundTouchReadBuffer = new float[_sourceReadBuffer.Length * 10]; // support down to 0.1 speed
}
private int VocodeAudioChunk(Chunk chunk, AudioFileReader audioFileReader, WaveFileWriter audioFileWriter)
{
///TODO Create the soundtouch outside this loop, and just reset it!!!!!!
var speed = (chunk.GetSpeed(ref options) - 1) * 100;
var samplesLeft = false;
soundTouch = new SoundTouch.SoundTouch <float, double>();
//Init soundtouch
soundTouch.SetRate(1.0f);
soundTouch.SetPitchOctaves(0f);
soundTouch.SetTempo(0);
//Set soundtouch rates
soundTouch.SetSampleRate((int)(audioFileReader.WaveFormat.SampleRate));
soundTouch.SetChannels(audioFileReader.WaveFormat.Channels);
soundTouch.SetTempoChange(speed);
//Sample count of chunk
var chunkSamplesLength = ((chunk.endFrame * options.samplesPerFrame) - (chunk.startFrame * options.samplesPerFrame));
int totalSamplesRead = 0;
//Set buffer size to 6750 or chunkSamplesLength if its less
int bufferSize = reAlignBuffer(chunkSamplesLength < 6750 ? chunkSamplesLength : 6750, audioFileReader.WaveFormat.BlockAlign);
//Init buffers
float[] inputBuffer = new float[bufferSize];
float[] outputBuffer = new float[bufferSize];
var samplesRead = 0;
var readAll = false;
int nSamples;
while (!readAll || samplesLeft)
{
if (!readAll)
{
utils.ReportStatus(WRITE_AUDIO_MESSAGE, chunk.startFrame + (totalSamplesRead / options.samplesPerFrame), options.frame_count, 2);
//Shorten buffer if needed
if (bufferSize > chunkSamplesLength - totalSamplesRead)
{
bufferSize = reAlignBuffer(chunkSamplesLength - totalSamplesRead, audioFileReader.WaveFormat.BlockAlign);
}
//Read next block of samples
samplesRead = audioFileReader.Read(inputBuffer, 0, bufferSize);
//End of stream or chunk finished
if (samplesRead == 0 || totalSamplesRead >= chunkSamplesLength)
{
//Stop reading more and flush the soundtouch buffer
readAll = true;
if (samplesRead > 0)
{
//Read the next block and and input them into soundtouch
nSamples = samplesRead / audioFileReader.WaveFormat.Channels;
soundTouch.PutSamples(inputBuffer, nSamples);
}
soundTouch.Flush();
}
else
{
//Read the next block and and input them into soundtouch
nSamples = samplesRead / audioFileReader.WaveFormat.Channels;
soundTouch.PutSamples(inputBuffer, nSamples);
}
}
do
{
//Get samples from soundtouch
nSamples = soundTouch.ReceiveSamples(outputBuffer, outputBuffer.Length / audioFileReader.WaveFormat.Channels);
//Write samples to file
audioFileWriter.WriteSamples(outputBuffer, 0, nSamples * audioFileReader.WaveFormat.Channels);
} while (nSamples != 0);
totalSamplesRead += samplesRead;
samplesLeft = soundTouch?.AvailableSamples > 0;
}
soundTouch.Clear();
return(totalSamplesRead);
}
