I’m going through this problem right now. I have mpg files which were supplied to me and I am adjusting them for the web in AE. But I’m not getting only one of the mysterious red frames. I have them popping up throughout the entire clip, here and there.
I decided how I’m going to fix this, and it may sound crazy, but I really need to get this done.
1. Duplicate the layer with the footage.
2. Offset it by one frame (either direction).
3. Set Opacity keyframe at the beginning to 0%.
4. Scrub through and look for red frames in the main layer. When I find one, I zoom in tight on the timeline and bring the opacity of the duplicate layer up to 100%, remembering to set a keyframe just before it to keep everything at 0% up to that point, and one after to bring it back down to 0%.
Did that make any sense?