On Wed, Aug 23, 2017 at 12:56 PM, Brion Vibber <bvibber@wikimedia.org> wrote:
This is happening now!

Video playback in Safari/IE/Edge now defaults to WebM instead of Ogg, and if all goes well, I'll disable the .ogv derivatives tomorrow.

Ok, this has now been done. Existing .ogv derivative files will continue to exist for a while to ensure cached page views don't encounter any surprises, but they will be deleted later, probably after 30 days.

Note that .ogg or .ogv video *uploads* will continue to work, and you may continue to upload .ogv videos if you have them -- they get automatically converted to WebM derivatives for playback.

For our friends in ops, it should now be safe to update video scalers without worrying about the buggy ffmpeg2theora package. :)

-- brion

Please give a shout at any unexpected problems.

-- brion

On Thu, Aug 3, 2017 at 1:27 PM, Brion Vibber <bvibber@wikimedia.org> wrote:
Due to ongoing issues with ffmpeg2theora & upcoming server upgrades, I'm planning to accelerate our migration from Ogg Theora video output to WebM VP8: https://phabricator.wikimedia.org/T172445

== When will it change? ==

Sometime in August 2017 as schedules permit, unless surprises pop up in final testing.

== What will change? ==

Folks using Chrome and Firefox may not notice any difference -- these browsers have used native WebM playback by default for some time. "Ogg" will disappear from the list of optionally-playable and downloadable formats.

In Safari, IE, or Edge where the 'ogv.js' compatibility shim is used, you will see videos automatically show up in WebM mode instead of Ogg mode.

There is a tradeoff: higher quality & lower bandwidth use, but higher CPU usage. On very slow computers or at very high resolutions, you may hit CPU limits at one resolution step lower than with Ogg.

== Why are we making this change? ==

* Eventually we need to go to WebM to support adaptive streaming, so this was always planned for the long term...
* For best quality we use an unreleased version of libogg and ffmpeg2theora, but there are still some bugs in there and we routinely get reports of odd hangs or crashes.
* Ops is updating the servers, and continuing to maintain the custom packages that are still crashy is getting to be problematic.
* Dropping the Ogg format for video will free up disk space and and CPU time, and should result in faster turnaround for derived file generation.

== What about Ogg audio? ==

Ogg is still being used for audio, and will not be affected.

-- brion