YouTube and Netflix publish first videos transcoded with AV1

[SolidComp]

https://www.anandtech.com/show/13365...oded-using-av1

The YouTube videos are low resolution for some reason.

Relatedly, I didn't realize that they published their 1.0 spec back in March: https://aomediacodec.github.io/av1-spec/av1-spec.pdf (3.3 MiB download)

[AiZ]

Hello,

You can download AV1 videos up to full HD with youtube-dl.

C:\Program Files (x86)\youtube-dl>youtube-dl.exe -F https://www.youtube.com/watch?v=w4LkSRXrK34 | findstr av01
395          mp4        426x240    240p  354k , av01.0.05M.08, 25fps, video only, 5.00MiB
396          mp4        640x360    360p  641k , av01.0.05M.08, 25fps, video only, 9.04MiB
397          mp4        854x480    480p 1013k , av01.0.05M.08, 25fps, video only, 14.51MiB
398          mp4        1280x720   720p 1796k , av01.0.05M.08, 25fps, video only, 26.29MiB
399          mp4        1920x1080  1080p 3042k , av01.0.05M.08, 25fps, video only, 45.78MiB

A quick test with "RED HDR Reel | Summer 2018 | Shot on RED" (Pentium G5400, Windows 10, ffplay) results in a few frames loss in quick moving scenes in 720p, much more pronounced in 1080p : 3 or 4 seconds freezes, not really watchable.

AiZ

[Gonzalo]

The YouTube videos are low resolution for some reason.

Meanwhile, the test videos use AV1 for resolutions that are lower than 480p, underscoring the fact that they are meant to test decoders that, for the moment, are going to be anything but optimized. This is on top of the fact that at the moment there are no hardware decoders that support AV1, so everything is being handled in software by the CPU to begin with. Eventually the codec will be used for content in 4K+ ultra-high-def resolutions, along with HDR and wide color gamuts.

[Jarek]

The impossible efficiency is not a surprise if they e.g. choose 16-multiplication per symbol range decoder instead of single in rANS - for any case, here is this discussion: https://encode.su/threads/1890-Bench...y-Coders/page7

[Jyrki Alakuijala]

dup deleted

[Jyrki Alakuijala]

Not sure what makes it slow, but it can be something else. If video is 50 mbps (~6 MB/s) a slow binary arithmetic coder running at 70 MB/s needs only a small fraction of one CPU for video decoding.

[Jarek]

This was only example of strange choice - I am most familiar with with.
I was also working on PVQ for them ( https://arxiv.org/pdf/1705.05285 ), but somehow lost any motivation last June.

[AiZ]

Hi,

Just tested some Youtube AV1 videos in Firefox 63 (about:config, set media.av1.enabled to true then enable AV1 in https://www.youtube.com/testtube). In Full HD, perfect play for "Balloons" and "Mountain Bike", 183 dropped frames for "RED HDR Reel". Impressive.

AiZ