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AV1

Posted: Thu Apr 12, 2018 1:06 pm
by rollin_eng

Re: AV1

Posted: Thu Apr 12, 2018 3:33 pm
by JohnAStebbins
Yes, we had a somewhat lively discussion in the AV1 issue thread on github yesterday https://github.com/HandBrake/HandBrake/issues/457

TL;DR, AV1 is about 30% better than x264 in quality vs. file size metrics. And it's about 6000x slower. I.e. you can make your files 30% smaller if you are willing to wait 9000 hours (a.k.a. 1 year) to encoder your feature length HD movie.

From the Facebook article:
On the other hand, the encoding computational complexity (in terms of encoding run time) of AV1 compared with x264 main, x264 high and libvpx-vp9 for CRF/QP mode was increased by factors of 5721.5x, 5869.9x and 658.5x, respectively, as shown in Figure 4.

Re: AV1

Posted: Thu Apr 12, 2018 4:15 pm
by rollin_eng
:) I did see they mentioned 10 second clips that they tested it on and my napkin math put that at 12+ hours to encode :shock:

I guess if you have tons of CPUs and are serving up billions of Taylor Swift videos it might make sense to save 30%.

Re: AV1

Posted: Thu Apr 12, 2018 4:38 pm
by mduell
The omission of x265 is curious at best.

Re: AV1

Posted: Thu Apr 12, 2018 4:40 pm
by JohnAStebbins
rollin_eng wrote: ā†‘
Thu Apr 12, 2018 4:15 pm
I guess if you have tons of CPUs and are serving up billions of Taylor Swift videos it might make sense to save 30%.
When VP9 was initially pushed out the door, it was also extremely slow (but still faster than current AV1 by about 12x). It took a bit over 2 years for them to bring VP9 encode speed up to the point that it was acceptable for inclusion in HandBrake. I expect AV1 will be on a similar trajectory and will be keeping an eye on it as things develop. In that time, CPU speeds will increase and perhaps we will see dedicated hardware encoders supporting AV1 built into CPU or GPU silicon.

Please don't t take my comments as any disparagement against AV1. I would really like to see it succeed. But some patience is in order here.

Re: AV1

Posted: Thu Apr 12, 2018 4:53 pm
by rollin_eng
Oh Iā€™m not advocating for its inclusion in HB, just putting this out there for discussion.

I also see that Apple and Samsung are not involved as I imagine a lot of videos for YouTube and Facebook come from their devices it will be interesting to see what direction they go.

Re: AV1

Posted: Thu Apr 12, 2018 5:10 pm
by JohnAStebbins
For those interested in the old VP9 saga:
viewtopic.php?f=26&t=27343&hilit=month

That thread explains why I am conservative about my estimates for an AV1 HandBrake roadmap.

Starting in June 2013, I did regular benchmarks as new release came out and posted my results to the forums. When VP9 reached an acceptable state (May 2016), we added support for it to HandBrake. I'll do the same with AV1, but post results to the github issue thread instead since that's were we track development status and issues now.

Re: AV1

Posted: Mon May 14, 2018 9:24 pm
by Woodstock
So, if you start an encode of a 3 hour UHD movie with the current AV1 encoder today, by the time it finishes, there will be faster hardware and software to do a second one?

Re: AV1

Posted: Tue May 15, 2018 3:01 pm
by JohnAStebbins
Woodstock wrote: ā†‘
Mon May 14, 2018 9:24 pm
So, if you start an encode of a 3 hour UHD movie with the current AV1 encoder today, by the time it finishes, there will be faster hardware and software to do a second one?
LOL. My 1 year estimate is for a 90 minute HD movie. So 180 minute UHD is x2 for duration and x4 for resolution, resulting in 8 years encode time. So yes, by then I would fully expect hardware and software improvements would make the next encode much faster :mrgreen:

Re: AV1

Posted: Tue May 15, 2018 4:39 pm
by Ritsuka
By the time it finished, it won't play anymore in the newer av1 version (until they stop making changes for real).