Wow, found a pirate mp4 release of an Australian movie that was muxed with L-SMASH.
Haven't seen a GPAC release yet so that's a definite proof at least most release groups are aware GPAC is cultist commercial garbage.
@steph Muxers take packets from multiple streams (e.g. H264 and AAC) and write them in an mp4 container.
MP4 is a notoriously cursed container because Apple decided it would be the best idea ever to make video editors save projects as MP4. Which means you can have crazy files like 10 second chunks located in reverse in the file played forward. And players have to deal with it.
So writing mp4 is as complicated as reading mp4 and so no real perfect implementation exists. Not even Apple's.
@steph If you're not doing anything weird like muxing AMR-NB/WB into mp4 with TTML subtitles and just have H264 and AAC then there's no difference between the two.
If you are doing something weird like even touching TTML: I feel sorry for you and I hope you're paid very very well.
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