Function initFilterChroma

source/NTSC.cpp:1111–1120

What filter is this ?? Filter Order: 2 -> poles for low pass ===========================================================================

// Filter Order: 2 -> poles for low pass
//===========================================================================
static real initFilterChroma (real z)
{
	static real x[CHROMA_ZEROS + 1] = {0,0,0};
	static real y[CHROMA_POLES + 1] = {0,0,0};

	x[0] = x[1];   x[1] = x[2];   x[2] = z / CHROMA_GAIN;
	y[0] = y[1];   y[1] = y[2];   y[2] = -x[0] + x[2] + (CHROMA_0*y[0]) + (CHROMA_1*y[1]); // inverted x[0]

	return y[2];
}

// Butterworth Lowpass digital filter
// Filter Order: 2 -> poles for low pass