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 <[email protected]> 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 <[email protected]>
> wrote:
>
>> Awesome sauce. Thanks Moritz!
>>
>> -- brion
>>
>> On Fri, Jun 29, 2018 at 7:39 AM Moritz Muehlenhoff <
>> [email protected]> 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
>>> [email protected]
>>> https://lists.wikimedia.org/mailman/listinfo/wikitech-l
>>
>>
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