QuickTime Player recording speed?

I think recordings are always at 1×. You can change that after recording by altering the frame rate without re-encoding. Then it should play back at a different speed, without telling QTP to use special speeds each time.

I would use the MP4Box command line tool for that, but there might be other tools with nice GUI.

MP4Box is part of GPAC, which you can download here: Downloads - GPAC.

MP4Box -add SourceMovie.mp4#video -raw 1 -new test

MP4Box -add test_track1.264:fps=30 -new DestMovie.mp4

This works on the video only. If you need audio to speed up/slow down as well, then you’ll have to do that separately, and re-mux.

To speed up, set the new frame rate to a higher value than the original (e.g. 60 fps instead of 30 for 2×).

To slow down, set the new frame rate to a lower value than the original (e.g. 30 fps instead of 60 for 2×).

If the new frame rate gets too high for smooth playback, then you may need to re-encode.

I know, quite cumbersome for a one-time viewing, but beneficial for repeat viewing or viewing by others/posting online.

The frame rate cannot be set manually in the GUI. The recording speed is fixed at 60 fps on my MBP/Sonoma. Slowing it down 2× would result in a very reasonable (for most uses) 30 fps.