I'm trying to sync the audio and video of 2 different files, one is a 15 FPS webcam stream with audio and the other is a screen share with 5 FPS. This is an educational setting.
I'm trying to do the math in my head on what causes the audio desync, is it the 10FPS difference?
I first extracted the audio from the webcam mp4 and inserted it into the video using mkvmerge, then used handbrake to encode it in constant fps and it didn't work. I tried 5, 15 and 30 fps in handbrake.
The question is, is there a way I can sync these by messing with FPS or some other property, or d I need to manually determine how desynced the audio is and manually shift it?