Oh and one more thing!

For the VP9 configuration I'll be enabling 1440p and 2160p ("4K") resolutions, which people can manually bump up to when watching videos with a suitable 4K source on a high-res screen. They use higher data rates, but only a small fraction of input files are 4K so should not significantly increase disk space projections for now.

These can take a long time to compress, so if we find it's problematic we'll turn them back off until the jobs can be split into tiny chunks (future work planned!), but it works in my testing and shouldn't clog the servers now that we have more available.

(Note that the ogv.js player shim for Safari will not handle greater-than-HD resolutions fast enough for playback, even on a fast Mac or iPad; for best results for 4K playback use Firefox, Chrome, or a Chromium-based browser.)

-- brion

On Thu, Jul 26, 2018 at 5:39 PM Brion Vibber <bvibber@wikimedia.org> wrote:

Ok, after some delay for re-tweaking the encoding settings for higher quality when needed, and pulling in some other improvements to the config system, all related updates to TimedMediaHandler have been merged. :D

If all goes well with the general deployments in the next few days, expect the beginning of VP9 rollout starting next week.

Changes since the earlier announcement:
* the new row-multithreading will be available, which allows higher threading usage at all resolutions; encoding times will be more like 1.5-2x slower instead of 3-4x slower.
* switch to constrained quality with a larger max bitrate: many files will become significantly smaller in their VP9 versions, but some will actually increase in exchange for a huge increase in quality -- this is mostly 60fps high-rate files, and those with lots of motion and detail that didn't compress well at the default low data rates.

-- brion

On Fri, Jun 29, 2018 at 9:46 AM Brion Vibber <bvibber@wikimedia.org> wrote:
Awesome sauce. Thanks Moritz!

-- brion

On Fri, Jun 29, 2018 at 7:39 AM Moritz Muehlenhoff <mmuhlenhoff@wikimedia.org> wrote:
Hi all,

On Thu, Jun 28, 2018 at 01:54:18PM -0700, Brion Vibber wrote:
> Current state on this:
>
> * still hoping to deploy the libvpx+ffmpeg backport first so we start with
> best performance; Moritz made a start on libvpx but we still have to
> resolve ffmpeg (possibly by patching 3.2 instead of updating all the way to
> 3.4)

I've completed this today. We now have a separate repository component
for stretch-wikimedia (named component/vp9) which includes ffmpeg 3.2.10
(thus allowing us to follow the ffmpeg security updates released in Debian
with a local rebuild) with backported row-mt support and linked against
libvpx 1.7.0.

I tested re-encoding
https://commons.wikimedia.org/wiki/File:Wall_of_Death_-_Pitts_Todeswand_2017_-_Jagath_Perera.webm
(which is a nice fast-paced test file) from VP8 to VP9, which results in
a size reduction from 48M to 31M.

When using eight CPU cores on one of our video scaler servers, enabling row-mt
gives a significant performance boost; encoding time went down from 5:31 mins
to 3:36 mins.

All the details can be found at
https://phabricator.wikimedia.org/T190333#4324995

Cheers,
Moritz

_______________________________________________
Wikitech-l mailing list
Wikitech-l@lists.wikimedia.org
https://lists.wikimedia.org/mailman/listinfo/wikitech-l