Convert MKV to MP4 Detailed (Fastest way, Lossless way, target for Apple iOS and spatial audio)
Convert MKV to mp4 without re-encode video.
tool used (mac)
MP4Tools by Emmgunn
https://emmgunn.com/wp/mp4tools-home/
the output file is good for
Apple device and can used for Airpods pro spatial audio
Key
2 channel audio use = AAC
6 channel audio use = AC3 or eAC3
othere you can include or drop.