// Gets the two longest consecutive gestures found
// in frames. -1 in off[ab] means no gesture found

// Here what counts: the bigger abs(dx[ab]),   the longer the gesture
//                   the bigger dy[ab]/dx[ab], the slower the gesture
void heuristics_getGestures( int const amount, int const * const values,
  int *offa, int *dxa, int *dya, int *dda,
  int *offb, int *dxb, int *dyb, int *ddb );

// Calculate an "energy" level contained in vu bars.
// to soften spikes, we correlate neighbouring bars
int heuristics_getEnergy( int const amount, int const * const values );