Attention shall be paid it's possible that what's going on is that they use the MPEG4 architecture but they're using a weird codec. MP4 (MPEG 4) is actually a standard that Apple really pushed with Quicktime 6. MP4(A digital multimedia format most commonly used to store video and audio, subtitles and still images.) It is known to have the best video quality of all three streaming formats listed here. Naturally, MOV is the standard and best video format for Mac.
MOV video file uses a proprietary compression algorithm developed by Apple Computer. MOV (A filename extension for the QuickTime multimedia file format) The following will list the best video format Mac supports and codecs you will need for a successful playback on your Mac (MacBook/MBP/iMac). In other words, only when the supported video comes with specific codec that Mac supports can your OS X play the file smoothly. The net result of this is that it's not just about whether the Mac can play the format or not, it's whether there is any Mac software to support the codec within the file too. The video and audio formats listed above are fair-weather fan of Mac computer. Download for Mac Download for PC Part 2: What is the Best Video Format for macOS?