I wonder how one could produce animated video glitch effects, like digital codec or connection problems or even analog cable problems.
I wonder how one could do something that can work on top of a video (to displace parts of it, mess up the colors in rectangular areas, create different noise patterns etc).
Reference 1: This movie poster, even though completely static, has very nice blocky artifacts. That are dependant on input image (the photo): http://www.motionelements.com/stock-video-8919500-noise-glitch-video-damage
Reference 2: (follow the link and watch video demos) http://www.motionelements.com/stock-video-8919500-noise-glitch-video-damage
What can I do to achieve similar effects?