Recording lossless video with OBS

Prior to changing settings, consider if a separate profile should be used. Duplicating the current OBS profile can be done with Profile > Duplicate....

Simple

Videos will be recorded in .avi format if this is done.

Advanced lossless H.264

Re-encode

Whichever way the video is encoded, it may not exactly be tightly compacted. For this, it may be recommended to re-encode the recorded lossless video.

ffmpeg -i "./input-video.mp4" -codec:v libx264 -codec:a copy -preset placebo -qp 0 "./output-video.mp4"

If -preset placebo is too slow. Try -preset veryslow.

Verify (frame extraction)

Check that these lossless videos are in fact lossless. I do this by extracting frames and manually checking them. Using FFmpeg, this command can be used:

ffmpeg -i "./video.mp4" ./frame%04d.png