Capture 30 vs 60 hz?

[ChasVideo]

I just started to use OBS Studio to do a full screen capture of video streams. The source is streaming at 3000 something for the older stuff. They have newer stuff at 6000 but I have not tried those yet. I captured at 60 Hz. When I took my captured video into a video editor, I noticed that all the frames were duplicated. So I assume the streaming is at 30 Hz. Sometimes the same frame is duplicated 3,4 or maybe 5 times in a row. I assume this is the streaming not updating. I think I should change the capture rate to 30 Hz to make the files smaller. In this case, is there any advantage to capturing at 60 instead of 30?

[jagabo]

Movies are typically shot at 24 fps. Streaming is typically at 24 fps or 30 fps.

If you capture a 24 fps stream at 60 fps the frames will alternate between being repeated 2 times and 3 times.

If you capture a 30 fps stream at 60 fps you will capture every frame twice. And if that 30 fps stream was originally a 24 fps movie one frame out of every 5 is a duplicate in the stream. Those frames will appear four times in your 60 fps cap.

If your capturing animated material, be aware that character animation is typically at 12 fps, panning shots at 24 fps. So you'll see lots more duplicates with cartoons and anime.

The best way to deal with this is to use a smart decimator (one that preferentially discards duplicate frames) after capture to restore the original film frame rate.