/// <summary>
/// Zwaraca liste wsp. mfcc dla kolejnych ramek sgnalu mowy
/// </summary>
/// <param name="wave"></param>
/// <returns></returns>
private List<double[]> GetMfccsHelper(LightWaveFileReader wave)
{
if (wave.Frequency != FREQUENCY)
throw new ArgumentException("Only 44100Hz waves are supported");
const int WIN_DELTA = WINDOW_SIZE - OVERLAP;
var results = new List<double[]>();
var windowData = new double[WINDOW_SIZE];
for (int windowBegining = 0; windowBegining < wave.SamplesCount - WINDOW_SIZE; windowBegining += WIN_DELTA) {
CopyWindowData(wave, windowData, windowBegining);
double power = windowData.Sum(x => Math.Abs(x)) / WINDOW_SIZE;
if (power > SPEAK_POWER_THRESHOLD) {
var mfcc = MFCCCoefficients.GetMFCC(FREQUENCY, windowData, filters, algorithmParams.MfccCount);
results.Add(mfcc);
}
}
if (results.Count < algorithmParams.SignalFramesCount) {
throw new ArgumentException("Too little usable voice samples found in wave file");
}
Debug.WriteLine("Z pliku wyodrebiono {0} ramek", results.Count);
return results;
}
private List<double[]> GetMfccsFromFile(string path)
{
LightWaveFileReader wave = null;
try
{
wave = new LightWaveFileReader(path);
}
catch (ThreadAbortException)
{
throw;
}
catch (Exception ex)
{
throw new WaveFileException(path, ex.Message, ex);
}
return GetMfccsHelper(wave);
}
private List<double[]> GetMfccsFromStream(Stream stream)
{
var wave = new LightWaveFileReader(stream);
return GetMfccsHelper(wave);
}
private void CopyWindowData(LightWaveFileReader wave, double[] windowData, int windowBegining)
{
Debug.Assert(windowData.Length == WINDOW_SIZE);
for (int i = 0; i < WINDOW_SIZE; i++) {
windowData[i] = wave.SoundSamples[windowBegining + i];
}
}
