iOS Safari doesn't support .webm files. I think normally iOS users would see the .ogg transcodes from TimedMediaHandler, but the player is suppressed on mobile. I don't have any device to test on, can you view the video on https://en.wikipedia.org/w/index.php?title=Pneumonia&mobileaction=toggle_view_desktop&useskin=minerva (desktop view with the mobile skin)?

The mobile interface doesn't yet interact with TimedMediaHandler and the Ogg compatibility shim -- we have to tidy up a few things in the switch from Kaltura player to VideoJS before enabling that.

(fixing things on the TimedMediaHandler end). I'll reprioritize that on my end higher since it's gotten delayed a bit past when we wanted to have it deployed.

@brion I thought with the new update to ogv.js that we could use the shim for webm, ie webm videos can be played on browsers that doint support webm, like we do for ogv?

@Paladox three separate issues:

1. TimedMediaHandler is not yet active on the mobile web view, as the videojs work is not complete (I'll be trying to finish that up in the next week or so). So at present it doesn't work regardless of anything else.
2. It doesn't matter what format the original file was in (webm, ogg, or anything else we support in the future) -- we convert all video files into both ogg and webm versions. Every file, regardless of original format, will be playable in Safari once TMH mobile mode is ready.
3. Yes ogv.js can play WebM VP8 if you send a WebM file to it, but our ogv.js adapter in TimedMediaHandler is not yet configured to do so -- so currently anything played via ogv.js in Safari or IE/Edge will be the Ogg version.

See also my notes at https://phabricator.wikimedia.org/T135869#2643272 about improved performance in iOS 10 and the difference in resolutions we can play between ogg and webm.