The first step for any NTSC decoder is to go to YIQ. From there, you go to any other color space of your choice. This is mainly for decoding the composite vid

The first step for any NTSC decoder is to go to YIQ. From there, you go to any other color space of your choice. This is mainly for decoding the composite video signal generated by a computer or console. For example, the NES generates a 12-step square wave for its video output, and you'd decode that to YIQ then convert that to RGB.