Digitize RGB video using DE0-Nano

You won't be able to use HSYNC to directly sync your PLL.

I assume (with your current implementation) you are adjusting the outgoing data, by a full clock cycle, every time you detect a 'change' to the incoming HSYNC pulse timing.

You need to 'hide' these timing changes in the VSYNC inter frame gap - the dead time between frames. Providing you deliver a full frame of video without adjusting your outgoing data and HSYNC timing your jitter should disappear.

Cheers,

Alex