Ringing Correction with Luma Transient Improvement

[eshaz]

Dependent on #341

Ringing Correction

• Removes ringing and other transient distortions from the luma channel
  • This measures the sync pulse rising edge (sync tip -> back porch) and determine the spectral difference between the pulses and the ideal sync pulse shape. This is averaged over 8 fields. A fixed impulse response filter is modeled from this spectral difference, and then is applied over the signal to perform an inverse equalization (i.e. subtracting the spectral difference)

Luma Transient Improvement

• This increases the slope of the luma transitions based on the measurements and correction amount gathered from the ringing correction stage.
• By default to be very subtle, but it is configurable to produce very sharp and clean luma transitions.