Esempio n. 1
0
  public static List<float[]> deconvol(float[] signal, int fs, int fenetre, int n0) {
    int nbfram = signal.length;

    int frameparfenetre = Math.round(fs * (float) fenetre / 1000);
    int recoupframe = Math.round(frameparfenetre / 2);
    float[] hamming = new float[frameparfenetre];
    for (int i = 0; i < frameparfenetre; i++) {
      hamming[i] = (float) (0.54 - 0.46 * Math.cos(2 * Math.PI * i / (frameparfenetre - 1)));
    }
    int fftsize = (int) Math.pow(2, Math.ceil(log2(frameparfenetre)));

    List<float[]> result = new ArrayList<>();

    int end = nbfram - frameparfenetre;
    for (int i = 0; i < end; i += frameparfenetre - recoupframe) {
      int to = Math.min(i + frameparfenetre - 1, end);
      float[] sfen = new float[to - i + 1];
      System.arraycopy(signal, i, sfen, 0, sfen.length);
      sfen = accentue(sfen);
      for (int j = 0; j < sfen.length; j++) {
        sfen[j] = sfen[j] * hamming[j];
      }

      FloatFFT_1D fft = new FloatFFT_1D(sfen.length);
      fft.realForward(sfen);
      for (int j = 0; j < sfen.length; j++) {
        sfen[j] = (float) Math.log(Math.abs(sfen[j]));
      }
      fft.realInverse(sfen, true);
      Arrays.fill(sfen, n0 + 1, sfen.length - 1, 0);
      fft.realForward(sfen);
      for (int j = 0; j < sfen.length; j++) {
        sfen[j] = (float) Math.abs(Math.exp(sfen[j]));
      }
      result.add(Arrays.copyOfRange(sfen, 2, Math.round(fftsize / 2) - 1));
    }

    return result;
  }
Esempio n. 2
0
  private void calculate() {
    float[] samples = getSamples();

    Window.apply(mWindow, samples);

    if (mSampleType == SampleType.REAL) {
      mFFT.realForward(samples);
    } else {
      mFFT.complexForward(samples);
    }

    dispatch(samples);
  }
  private void processRecordedData() {
    mIsProcessing = true;

    float[] recordedDataFFT;
    recordedDataFFT = FrequencyDetector.convertToFloats(mRecordedData);
    fft.realForward(recordedDataFFT);

    float[] halfAbsFFT;
    halfAbsFFT = FrequencyDetector.absAndHalve(recordedDataFFT);

    int[] peaks;
    peaks = FrequencyDetector.identifyPeaksAndRemove(halfAbsFFT);

    String peakString = "";
    for (int e : peaks) peakString += e + " ";
    Log.d(TAG, peakString);

    int frequency = FrequencyDetector.detectFrequency(peaks);
    if (frequency != -1) this.updateStrings(frequency);

    mIsProcessing = false;
  }