Here is the ffmpeg media info from the Quick Sync video out of OBS: Here's some more info that I probably should have included the other day It even helps to convert audio to play FLAC, OGG, WMA, APE, DTS, AU, RA, 3GA and more in QuickTime. This wonderful MP4 to QuickTime Converter also can convert other video formats to QuickTime format to successfully play AVI, WMV, MKV, VOB, FLV, MPG, RMVB, MOV, 3GP and etc in QuickTime. IDealshare VideoGo is just the ideal MP4 to QuickTime Converter which can convert all kinds of MP4 files encoded with whatever video or audio codecs to QuickTime more compatible MOV or MP4 on Mac or Windows. In order to solve MP4 won't play in QuickTime issue, we had better convert QuickTime unplayable MP4 to QuickTime supported format. How to Play Any MP4 in QuickTime Successfully? That is, if the MP4 video contains QuickTime unsupported audio or video codecs, QuickTime will refuse to play this kind of MP4 files. However, QuickTime just supports a few video and audio codecs in MP4 format.

Acting as a video container format, MP4 is the package and can contain video and audio components encoded with different types (codecs).

Cant open mp4 on mac