New install of Ubuntu 15.04 (on an otherwise fully functioning dell XPS 13 9343). I've been having difficulty getting HTML5 video to play on Firefox.
My test case is Plex and Youtube, both of which seem to default to using flash player (urgh, I would very much like to banish it!).
If I use Chrome (not so great as I have a high DPI screen) on Ubuntu the html5 player works fine for youtube and plex. Similarly if I boot into windows plex and youtube use the html5 player on both chrome and Firefox.
I therefore assume I’m missing a video codec or Firefox setting. Ubuntu restricted extras are installed.
Can anyone recommend a place to start looking
media.fragmented-mp4.*
configuration settings but this is causing plex to hang. Will post an answer if I crack it, but i'd appreciate any specific guidanceCurrently MSE-enabled versions of Firefox default to using the lowest quality available, though it can be forced to use a higher-quality by specifying one using the gear settings for the video. This issue is due to this [bug](https://bugzilla.mozilla.org/show_bug.cgi?id=238041).