I've done some more fixes to ogv.js to perform *much* smoother on slower machines by running the decoders in Web Worker threads. If there's no objection, I'm going to land ogv.js (and a number of smaller fixes for media playback) into TimedMediaHandler later today.

ogv.js is a JavaScript compatibility shim for Ogg and WebM video in Safari and IE/Edge which don't support free codecs natively. (IE/Edge on desktop can use native WebM components if you install them manually but still lack Ogg audio support.) This replaces the old Cortado Java applet that no longer works on most current computers.

Please feel free to help review and test! Live demo site https://ogvjs-testing.wmflabs.org/

MwEmbedSupport:

* https://gerrit.wikimedia.org/r/#/c/227074 - fix fullscreen video in IE

TimedMediaHandler:

* https://gerrit.wikimedia.org/r/#/c/219398 - TMH transcode list ordering fix

* https://gerrit.wikimedia.org/r/#/c/222294 - misc small buglet

* https://gerrit.wikimedia.org/r/#/c/226999 - fix double-playback in IE/Edge with native webm installed

* https://gerrit.wikimedia.org/r/#/c/227066 - fix the popup player on first open

* https://gerrit.wikimedia.org/r/#/c/227155 - increase quality of Ogg Theora transcodes, add 240p with the old bandwidth of 360p

* https://gerrit.wikimedia.org/r/#/c/226957 - update ogv.js libs

* https://gerrit.wikimedia.org/r/#/c/165478 - ogv.js for desktop

There's also my basic mobile integration, which requires some more work to support suitable controls:

https://gerrit.wikimedia.org/r/#/c/217485/

-- brion