I have searched everywhere, and I could not find any media player (for Windows) capable of playing back 1000fps video at 24fps. Can anyone suggest software? I'm not willing to any greater price than free. I tried Windows Media player and VLC media player. VLC can get close, but not quite 24fps. It must be able to play back the video at between 22 and 26 fps as well as normal speed. I know professional high-speed playback software exists, I just can't find it. An alternative solution would be to suggest software that can convert video to play back at 24 fps. A third alternative: is it possible to modify the binary data in a file to change the playback rate?
You can use the free command-line tool
ffplay, which is part of the ffmpeg project.
ffplay in.mp4 -vf setpts=N/24/TB,fps=24
You can change the value
24 above to any arbitrary value. Just remember to change both instances in concert.