[popcornmix]

I'm thinking that the Pi output is dropping out for a split second. It only does this when playing TV, never when it's just the gui on the screen. I don't have any videos that I can check it with, other than a bunch of low res TV recordings and they seem ok the vast majority of the time, but my wife said she saw it happen once with one of them. Maybe this all connected to deinterlacing since the 720p TV seems ok?

Try setting deinterlace to "off". If this fixes it, I'd suggest trying:

Code:

hvs_priority=0xf3fc

in config.txt