[mantasm]

How would you implement analog parity? Parity doesn't translate well as a concept into the analog space.

You can take an analog signal and "quantize" it into sixteen possible values so that you can apply a parity algorithm that returns sensible results and doesn't fail with expected noise, but you're digitizing the signal.

[sathackr]

I don't understand what analog has to do with it? The video is digitized first, then error-correction (parity?) information added before transmission, so all parity would be related to the digital bitstream -- unless I missed something?