See also: this talk from a Vimeo engineer about the video encoding horrors they've encountered in the wild.
https://www.youtube.com/watch?v=cRSO3RtUOOk / https://speakerdeck.com/demuxed/things-developers-believe-ab...
https://www.youtube.com/watch?v=cRSO3RtUOOk / https://speakerdeck.com/demuxed/things-developers-believe-ab...