Code to play Video foreward and backwards

my questsion is not direct releated to shotcut, but i think any of you can help me :slight_smile:

I sometimes analyse Sport Videos (Floorball) with my son. But as you know, vids are not encoded to be playable backwards :frowning: . In shotcut, the proxyfiles seam to be able to be played in both ways :slight_smile:
can someone tell me a codec/settings to encode videos so it can be played, rewinded slowly and so on?

maybe even a player like shotcut (in know its not a player) witch has nice key-“shortcuts”.

Did you mean “Proxy” files or files “Converted to Edit-Friendly”. Proxy files are lower resolution files. Edit-friendly files have a GOP setting of 0 or 1, which means they consist only of I-frames. This means that when a video player needs to display a frame it does not depend on any other frame to decode that one, so skipping backwards and forwards through the video should be seamless.

Most videos have large GOPs, to keep filesizes reasonable. A 30fps video exported with the default Shotcut settings will have a GOP of 150 (a 60fps video will have a GOP of 300)! This means that when you skip backwards the video player has to find the relevant I-frame, that gould be several hundred frames in front of the one it is trying to display, which is why it can be slow and struuring.

thank you for those information. Both will work but of corse, i like the better quality.
so i will give a tray to convert an example file with GOP to a low value 0 to max 30.
i play with:
ffmpeg -i test.mp4 -ss 00:10 -to 00:30 -g 10 testG10.mp4
to create sample files

and found a Player witch can step frame by frame fore-/backwards:


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