Prior to changing settings, consider if a separate profile should be used. Duplicating the current OBS profile can be done with Profile > Duplicate....
Simple
- In the output tab in settings with “Output Mode” set to “Simple”. Use “Lossless Quality” preset on the recording section.
- On the advanced tab, set “Color Format” to “I444 (8-bit, 4:4:4, 3 planes)”.
Videos will be recorded in .avi format if this is done.
Advanced lossless H.264
- Ensure that in the output tab in settings with “Output Mode” is set to “Advanced”.
- Switch over to the “Recording” tab.
- Set options in the “Recording Settings” section:
- Recording Format: Hybrid MP4 (.mp4)
- Video Encoder: x264
- Optionally set “Audio Encoder” to any lossless format.
- Set options in the “Encoder Settings” section:
- Rate Control: CRF
- CRF: 0
- x264 options (separated by space):
qp=0 - Set “CPU Usage Preset” to highest of what your device can handle. Or set to fastest if you plan to re-encode the video.
- On the advanced tab, set “Color Format” to “I444 (8-bit, 4:4:4, 3 planes)”.
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.
For a five second 60 FPS video of Gassy GaoGao gameplay, this file is 355KB. It should be playable in most modern browsers. Though, Discord’s client doesn’t seem to support playback.
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