First release of dav1d, the AV1 decoder | Hacker News Reader

First release of dav1d, the AV1 decoder

jbkempf.com

153 pointsnimbs27 comments

I am thinking if H.264 AVC will be like Jpeg, where the worse is actually better. They are ubiquitous, and hardware decode in visually all Smartphone, and seems to be good enough for a lot of cases (non-4K usage).

But it is still nice to see AV1 coming along, especially coming from VLC (dav1d) and Xiph ( rav1e ) .

Agreed, but I'm very curious which codec (h265 or av1) will eventually "win" in the 4K+ and HDR space.

Perhaps AV1 will in the loooong term, but as of today h265 is what every 4K Blu-Ray uses and just about every modern device has a hardware decoder. So that’s gotta count for something.

H.265 is a much worse patent minefield than h.264 ever was: the h.265 patents are owned by different patent pools with different licensing terms, some of which even without revenue cap.

The only way to relatively safely produce h.265 content is to be one of these companies in one of the patent pools.

AV1 in contrast is supposed to be free of patents and open for everybody to use. Of course there could still be some patent being violated and there's no legal entity to fight for you if you get sued, but given the mess around h.265, this might still be the better option.

AV1 is backed by multiple soft- and hardware manufacturers, so between that, the free licensing, and the legal murkiness of h.265, this might yet take off.

I certainly hope so. It would be the first time in decades that the best media codec is also patent free and useable by everybody.

>AV1 in contrast is supposed to be free of patents

It is not, it never was, and never will be. It is only Royalty Free.

"free of patents" is like atomic hydrogen; a very short lived state in practice.

Ummm...kinda the opposite? The terminal value is always "patent free" :-)

My guess would be AV1, on the other hand this is really the space h265 occupies at the moment so maybe they will be effective at holding on to it.

I fully expect AV1 to become the new 'de facto' video format on the web which is the crown h264 has held for ages. No royalties, better compression and wide hardware support coming will make it a very attractive choice.

And as streaming will also move towards 4k+, given that all the streaming giants (Google, Netflix, Amazon) are directly backing the development of AV1 it would surprise me if they did not phase out HEVC in favour of AV1 for all their 4K+ needs as well (Youtube doesn't support HEVC at all).

I still consume nearly all of my content in 720p. The bandwidth requirements usually outstrip my need for fidelity. This is especially true when traveling when I don’t have access to my own broadband. It’s easy to get stuck in a place with slow internet services.

I don't think h265 will ever be widespread as h264. I am counting on H266, which has an industry formed alliance MC-IF for patents and they include All most of the original H.263, H.264, H.265 members. ( Missing Qualcomm )

Hopefully they will work out a deal and move things forward.

I believe the compression benefits of AV1 to H.264 are greater than Jpeg to newer versions of image compression. Also, when you're talking about video, the sizes of files are magnitudes greater than images. I believe as long as we achieve backwards compatibility and easy conversion of video files, AV1 will be the future.

It depends on the target bitrate, but from what I've seen at high quality, the difference between HEIF and JPEG is comparable to the difference between H.265 and H.264.

I think your second point is more important though. There are basically two main cases for images. On the one hand, you have images which are an input to some process, like editing or publishing, where people are unwilling to sacrifice any information, lest the errors accumulate. On the other hand, you have images intended for final consumption. By modern standards, those images are already so small that saving 50% isn't usually worth either losing compatibility, or putting in extra effort to offer a fallback.

There are some in between niches of course. Apple has bet on one in iOS with phone photography. That makes sense because many people will have a large volume of images, but they're not professional photographers who need perfect fidelity. I don't know if that's actually worthwhile to most users, though, since they too have to deal with the compatibility issue.

iOS still exports in jpeg unless it knows for sure the receiver (another Mac or iOS device with the right version) supports heic, or you change a setting to force it to always export heic. So users should rarely run into the compatibility issue.

But 4K is kinda ready. Majority of YouTubers switched to it already, some years ago.

Personally I find 1080p not enough nowadays.

The problem is 4K are streamed in much higher bitrate, making the video looks better. But in reality, if 1080P had the same bitrate you might not be able to tell the difference. Standard Youtube using VP9 stream 4K at nearly 20Mbps. Most of the best encoded BluRay torrent aren't even using this bitrate, and they are still using x264.

Two recent discussions:

https://news.ycombinator.com/item?id=18504930

https://news.ycombinator.com/item?id=18114698

how are the optimized encoders coming along? last i remember it was 1000x slower to encode than typical.

Last I saw, the official AV1 encoder had gone down to 16x slower than VP9, but that was a couple of months ago so things might have improved further.

Also there's rav1e which bodly claims to be the fastest (and safest) AV1 encoder, but it's still in early development so it probably doesn't make any sense in benchmarking it at this stage.

When is this coming to Firefox?

It's available in Firefox Nightly.

The firefox implementation is currently lacking the ASM code optimizations and actually runs worse than the default libaom implementation.

I tried it out in Firefox 65 beta. You can enable dav1d via about:config by setting "media.av1.use-dav1d" to true.

dav1d seems to perform worse than libaom for me on some videos I tried. I have a 2014 MacBook Pro with a 2.2ghz Haswell i7 (i.e. with AVX2).

Firefox using libaom struggles to play YouTube AV1 video at 1080p60 on my system. It gets to a point where it drops too many frames and the video becomes unwatchable. For example:

https://www.youtube.com/watch?v=Fmdb-KmlzD8

I hoped dav1d would perform better than libaom on that particular video at 1080p60, but if anything it performs worse.

I'm not clear if that video is 8-bit or 10-bit color. If it's 10-bit color then that would explain it because dav1d is not optimized for 10-bit video yet.

> dav1d seems to perform worse than libaom for me on some videos I tried.

As far as I know, the Firefox buildsystem does not compile dav1d with asm yet. So, that is expected, for now.

Ah, that explains it then. Thanks.

Hopefully they'll enable the asm code during Firefox 65 beta.

That typo in the first bullet of the "Release" section is really bothersome to me oddly. Less know ones... less know... know... blah

That's the trouble with spellcheck. It can't tell you that you are using the incorrect real word.

There are grammar checkers that can pick up on those errors. Microsoft Word has one built in (green underline versus red).

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