node-faststart VS un-istore

The key to understanding this issue seems to be "-movflags +faststart". The TLDR is that Apple apparently isn't "fast-starting" their MPEG-4 files before distribution.

This became a thing when distributing QuickTime Movies on the internet became a thing (it's not an issue with random-access media), because one needed Movie metadata at the front of the file in order to support progressive playback. Because the MPEG-4 file format is effectively the QuickTime Movie file format, the need to put metadata at the front of the file continues if you want viewers/listeners to be able to play files as they're downloading.

That Apple isn't performing this extremely trivial pre-distribution process is extremely curious. It makes me wonder if this "common knowledge" was lost along the way, or if the people who would know this kind of super-obvious production step just aren't the same people in charge of Apple Music standards.

For anyone curious about what fast-start implementations look like:

https://github.com/FFmpeg/FFmpeg/blob/master/tools/qt-fastst...

https://github.com/kanongil/node-faststart

Good point about the watermarking, although 500 kB still seems rather generous for that: As far as I'm aware, the "watermark" only encompasses a few IDs plus name and e-mail of your Apple ID (compare https://github.com/avibrazil/un-istore).