srecord noeq HamburgerAudioHaarFeature(IAudioSample sample, double start, double end) {

  double[] positions = new[4];

  *(IAudioSample *sample, double... *positions) {

  }

  double factor = 1;

  double length() { ret positions[3]-positions[0]; }

  DoubleRange meatRange() { ret doubleRange(positions[1], positions[2]; }

  double meatHeight() { ret l(meatRange()); }

  double blackArea() { ret length()-meatHeight(); }

  double whiteArea() { ret meatHeight(); }

  double get(int channel) {

    double blackArea = blackArea();

    double whiteArea = whiteArea();

    double whiteSum = sample.sampleSum(channel, positions[1], positions[2]);

    double blackSum = sample.sampleSum(channel, positions[0], positions[1])

      + sample.sampleSum(channel, positions[2], positions[3]);

    ret mul_optFor1(factor,

        (doubleRatio(whiteSum, whiteArea)

       - doubleRatio(blackSum, blackArea))/255.0);

  }

  // 0 for transparent, 1 for white, -1 for black

  double getMask(double x) {

    ret x < positions[0] || x >= positions[3]

      ? 0.0

      : x >= positions[1] && x < positions[2]

      ? factor

      : -factor;

  }

  Channels<Double> get() {

    ret mapChannels get(sample.channels());

  }

  HamburgerAudioHaarFeature inverted() {

    HamburgerAudioHaarFeature f = new(sample, positions);

    f.factor = -factor;

    ret f;

  }

  HamburgerAudioHaarFeature shifted(double ofs) {

    HamburgerAudioHaarFeature f = new(sample, doubleAdd(positions, ofs));

    f.factor = factor;

    ret f;

  }

  void pinOuter(DoubleRange r) {

    positions[0] = r.start;

    positions[3] = r.end;

  }

  bool ok() {

    ret doublesAreSorted(positions);

  }

}