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Comment by orastor | Hacker News Reader

Why not admit AV1 is all around better and work on it instead

What value do you think your comment adds to the conversation? H.265 is a widely-used standard which millions of devices support and since it's older than AV1 anyone who cares about, for example, iOS users has the choice of using either H.265 or H.264 but not AV1. Even if you're using Chrome or Firefox on a desktop, you often don't want AV1 unless you have a burly CPU, aren't running on battery, and don't mind hearing your CPU fans (a quick search will show this is true even for WebM because millions of people still use devices which have hardware H.264 but require CPU-based decoding for WebM). If that's not true for you, a high-quality open-source H.265 encoder is a great tool.

Here are the current support stats — note the distinct lack of a common format newer than MPEG-4 even before you consider hardware support:

https://caniuse.com/#feat=mpeg4

https://caniuse.com/#feat=hevc

https://caniuse.com/#feat=webm

https://caniuse.com/#feat=av1

A lot of your argument is based on H.264, which is not part of the question. H.265 is not extremely common and also hard to CPU decode.

I’m aware of that but did you notice where I mentioned iOS and linked to https://caniuse.com/#feat=hevc at the bottom? That was why I mentioned the lack of a common option beyond MPEG-4 — iOS has H.265 support in hardware so if you want a newer codec that’s your only option for a fairly large group of people, especially in the United States, and it’s where battery life matters a great deal.

https://www.scientiamobile.com/growing-support-of-hevc-or-h-... has it at 80% of iOS and 60% of Android, which is a LOT better than 0% for AV1, and might even allow only doing 2 formats if enough of the devices with WebM also support HEVC.

I think you're better off going with VP9 as your next-gen codec for now rather than HEVC despite the lack of iOS support.

That's what Twitch is doing, for example. They say VP9 is a particularly good fit for them because they're getting a 25% bitrate reduction over H.264 in live streaming, they don't want the licensing headaches of HEVC, and because most of their viewers are using Firefox or Chrome on the desktop.

Apple joined the Alliance for Open Media so they'll be adding AV1 support eventually. It'd be good if they also added VP9 support, especially because some of their laptops already have hardware decoding for VP9 in the CPU. Most Android phones have VP9 support so iOS joining in would be great.

For personal media libraries, patents don’t matter while quality, size, and hardware support do. So HEVC > VP9.

It isn't a question of patents, it's a question of licensing. VP9 and AV1 patents are licensed under royalty-free terms and free for all use-cases. Royalty-free formats are better for the health of the internet and the computing industry generally. I'll always use royalty-free formats where I can. It's just simpler.

>Apple joined the Alliance for Open Media so they'll be adding AV1 support eventually.

They joined a organisation when their logo isn't even used.

Compared to something the fully support and wants to move forwards with VVC [1]

[1] https://www.mc-if.org

Apple joined AOMedia at the highest membership level. If Apple didn't care about AOM then it would have been simpler not to join at all.

If you can ship a custom decoder, don’t care about battery life, and have enough CPU headroom, yes, VP9 is an option. For everyone else, until AV1 hardware ships it’d be better to stick with H.264 than use VP9 if you can’t figure out a way to make H.265 work in your business.

> don’t care about battery life

VP9 has broader decoder support than H.265. Even when you don't have a hardware decoder, the software decoding for VP9 is not bad. I play VP9 video in VLC on my iPhone 7 and I have survived to tell the tale. It's not all doom and gloom.

Yes, an iPhone CPU is usually fast enough not to drop frames but if you care about battery life it’s not competitive. Again, I’m not saying that VP9 is bad but rather that anyone serious needs to support both formats until AV1 has MPEG-4 levels of pervasiveness, especially if you’re publishing on the web.

No, if you're publishing on the web using VP9 is the better choice. VP9 is supported in more browsers and there's no point having the licensing hassle of H.265. And as Netflix found, VP9 outperforms H.265 by 12% with the right encoder:

https://medium.com/netflix-techblog/performance-comparison-o...

So the sensible strategy is H.264 for devices that don't support VP9 and VP9 everywhere else.

Better? There isn't AV1 hardware decoding, encoding takes much much longer than h.264/h.265. We are only now starting to be able to target devices with h.265 reliability.

It is surely better in the long term. AV1 encoders need a lot of work still to be usable though in real time, which is critical for something like WebRTC.

For example, rav1e still needs multithreading support: https://github.com/xiph/rav1e/issues/132

And once encoders are ironed out, hardware support is also needed.

Can you post a link to some data so we can compare both, please?

https://duckduckgo.com/?q=av1+vs+x265&t=ffnt&ia=web

I read a few times the results at texpion (the first 4 results from that DDG query), and I must say that I'm confused. I was expecting to see some particularly good results in favor of AV1, but the "Conclusions" section in page 1 state that:

* both x264 and x265 take less time to encode and the produce smaller files (lossless compression)

* AV1 takes 160x-190x more time than x264 (lossless compression)

* AV1 can't take advantage of multi-threading the same way x264 and x265 can. Neither for encoding nor for decoding.

* AV1 requires 3.5x-6x more CPU power to decode than x264

I just fail to see how AV1 is "all around better". Can you share another link? Maybe this time more specific so I can read the data you used to get to that conclusion.

> AV1 can't take advantage of multi-threading the same way x264 and x265 can. Neither for encoding nor for decoding.

Dav1d is an AV1 decoder which takes advantage of multi-threading:

https://code.videolan.org/videolan/dav1d

https://medium.com/@ewoutterhoeven/dav1d-0-1-0-release-the-f...

BitMovin and Intel both have AV1 encoders which can take advantage of multiple cores. BitMovin demonstrated live AV1 video almost two years ago:

https://bitmovin.com/bitmovin-supports-av1-encoding-vod-live...

https://bitmovin.com/constantly-evolving-video-landscape-dis...

https://github.com/OpenVisualCloud/SVT-AV1

The article (nor my comment) doesn't say that AV1 can't do multithreading. What the article at texpion says is that it can't make CPU cores sustain hight loads the same way x264/x265 does.

That said, I have no idea whatsoever about video codecs; I'm just saying what I understood from the link I was provided with.

dav1d can make use of the CPU at sustained high loads if you want it to. It can do over 30 frames a second on even a single core of an Apple A12X, and over 100 frames on an A12x using multiple cores.

AV1 isn't mature enough to make it worth sinking a bunch of time into optimizing an encoder for yet. There will eventually be multi-threaded AV1 encoders but the format needs to stabilize first. There is no guarantee that a file you encode today will play on anything in the future. It is in no way ready for primetime, maybe in another 3-5 years it will be at the enthusiast/pirate stage and commercial usage in 7-10 years.

Also, do bear in mind that the primary use-case here is for Youtube to cut down their bandwidth consumption, and other similar users who don't mind doing a one-time encode that either takes a while, or needs to be run with process-level parallelism (different files at the same time). Multi-threaded encoders are not really a primary design goal here.

The format is practically worthless until there is a hardware decoder for it, nobody will software-decode AV1 on their smartphones or laptops. Nobody is going to design a hardware encoder until the standard stabilizes. Google can do all the Youtube encodes they want but they are going to have to keep developing and serving H264 for a long, long time.

> nobody will software-decode AV1 on their smartphones or laptops

Dav1d (https://code.videolan.org/videolan/dav1d) runs fine on my laptop for 1080p AV1 decoding. Your mileage may vary.

> Nobody is going to design a hardware encoder until the standard stabilizes.

NGCodec will release a hardware encoder this year. They use FPGAs for their encoders. Twitch uses NGCodec for their live VP9 streaming:

https://ngcodec.com/news/2019/1/7/ngcodec-announces-av1-supp...

https://blog.twitch.tv/how-does-vp9-deliver-value-for-twitch...

It might run fine, but it won’t compare to the hardware decoder when running on battery.

I have an insufficiency of pearls to clutch.

I thought they nailed down the bitstream already?

"On 25 June 2018, a validated version 1.0.0 of the specification was released. On 8 January 2019 a validated version 1.0.0 with Errata 1 of the specification was released."

The bitstream is an important milestone but it normally takes years of optimization for a codec to really hit peak quality. There are many decisions to be made during the encoding process which have an impact on file size, quality for specific content types, required decoder resources, etc. The first generation implementations often produce files which are notably larger because they're doing the simplest, most conservative encoding process and subsequent tools may have far more sophisticated optimizations.

If it's more familiar, think of it as similar to saying that the x86 or ARM instruction set has been finalized: the first generation will work but over time every component will be optimized to improve certain areas and there will be tailored versions for specific applications (e.g. video codecs used in chat have hard latency requirements while Netflix can afford a LOT of optimization time for a file which will be streamed a billion times).

I agree with all of that. My point is that AV1 is at the point of maturity where we need to sink maximum effort into improving the encoders, and what you're saying seems to support that.

In the end AV1 will likely have about the same level of adoption as VP9 ... pretty much googe/youtube only. Allowing Google to monopolize video standards is not something that the hardware world is going to accept. HEVC already has near universal hardware support. Why bother with supporting AV1?

Google, Netflix, Amazon... so basically overwhelming majority of the video on the Internet. Left is broadcast video, where the HEVC support can be relegated to set-top boxes.

So yes, hardware world is going to accept AV1.

It's not just YouTube. Netflix uses VP9:

https://medium.com/netflix-techblog/more-efficient-mobile-en...

https://medium.com/netflix-techblog/performance-comparison-o...

Twitch uses VP9:

https://blog.twitch.tv/how-does-vp9-deliver-value-for-twitch...

Both Twitch and Netflix will use AV1 in the future.

VP9 is the same generation as HEVC and performs about the same so the only reasons to favor one over the other would be financial and client support. For many providers this means 3 copies: VP9 for Android, HEVC for iOS/Mac, and H.264 for older devices.

AV1 is newer and should offer improvements over both previous generation codecs. Hardware support will be a significant factor but it’s looking as if in a few years you’ll have the option to use one better format on most modern devices.

The lack of hardware support in my home theater ecosystem makes AV1 a non-starter for me.

> The lack of hardware support in my home theater ecosystem makes AV1 a non-starter for me.

What is a home theater ecosystem? If you're using a HTPC with Kodi or Windows, you'll either soon have good realtime AV1 decoding, or already have it.

It takes time, but it is coming along faster than other rollouts over the last couple decades. Microsoft had a usable AV1 decoder in the windows store basically a few weeks after the bitstream was frozen; and as dav1d is hooked in to more applications, the decode performance on commodity hardware (which can be cooled passively) is becoming good enough to be practical.

I use my Nvidia Shield as well as the built in "smart" functionality on my TV, and a Roku Premiere+ in the basement. I also use an iPad Air to watch TV shows on the treadmill. Since a large chunk of the TV and movies I watch are ripped from disks I bought, I need to stick to formats these devices support. Apple put out a surprisingly competent software HEVC decoder for my iPad Air, and everything else here supports it natively.

By the same criteria, HEVC is non-starter for me. Unfortunately for me, the world around me didn't stop developing, just to fulfill my wishes.

Expect the same with AV1.

h.264 is still completely viable, it's just a matter of storage. I have no burning desire to go back and re-rip my older blu-rays in HEVC.

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