Is it possible to remove movie frames that contain no audio?

Question

I have an AVI file that contains a lot of empty frames, i.e. frames without audio or even picture changes. Is it possible to remove those frames?

Specifically, I have an 8 GB AVI file where almost 20-30% of the frames are empty. Their length and positions in the file are random (some can be short, only 1 second, while others can be 10 minutes long).

I would appreciate any advice on how to remove these frames. Or are there tools or other video formats like MP4 which are more suitable?

Answer 1

I actually once built a tool that does exactly that (except for the sound factor). I don't have the tool anymore but I will describe how it works (and maybe build it again soon)

Using ffmpeg you break down the film to frames, one per second, then use compare to delete all the duplicate (>90% similarity) images.

Aftet that, you'll end up with different sequences of numbered image files (1..20,30..45,etc.), so you take that up, and again use ffmpeg to keep only the portions of the file that has mostly different frames.

I know this is a descriptive answer rather than a practical one, but I'll work on that tool and update here when possible.