[j1elo]

This is what the MP4 format calls the "moov atom".

Writing metadata at the end, instead of periodically interleaving it inside the file, is not only useless for web playback, but also for any creation process (i.e., live recording) which intends to call itself robust. Imagine recording a 1-hour long video, only to have some unrelated issue abruptly stopping it all (e.g. the application crashes, or the video camera suddenly loses power), thus rendering an unplayable file because the damned metadata didn't get to be written at the end of the file...

(luckily there are post-process methods that in some cases are able to restore such broken files, but still, a priori the file will be unplayable)

[pavlov]

> This is what the MP4 format calls the "moov atom".

One of the few surviving legacies of Apple technology created during the Jobs interregnum.

Like everything else not from NeXT, the modern Apple has killed QuickTime, but they can’t eliminate its concepts and wacky constants from the MPEG-4 standard.

[galad87]

And that's the reason fragmented mp4 were invented.