rlaphoenix / chapsnap Goto Github PK

Some way to speed up analyzing UHD HEVC videos would be nice. It's likely long simply due to the amount of time needed to decode and run scene detection on every frame.

On my end, it's taking 5-6 minutes per 22 minutes of content. That doesn't seem too bad but when you need to run this on 100s of files, that adds up quickly.

The algorithm used is just a simple threshold on the scene change score calculated by FFmpeg.

Since a Fade-out doesn't wildly differ from its previous frame, the entire transition occurs without detection. Similarly, the Fade-in works out the same.

This is only a problem when a Fade-out is met with a Fade-in directly after. A Fade-out to then a jump-cut works fine. A jump-cut to a Fade-in also works fine.

The only fix I can think of is to remove the frames after the start of the transition, and before or on the end of the transition. This results in what looks to be a jump cut instead of a fade transition and the algorithm by FFmpeg with the threshold will pick it up as a Scene Change. However, doing so in an automated way is not such an easy task to pull off.

Currently, support for this feature is only possible with MKV files using mkvpropedit. Perhaps use FFmpeg for adding chapters on other formats.