Dav2d

"Too Many Requests"

- https://web.archive.org/web/20260531130034/https://jbkempf.c...

- https://archive.md/ln5UE

'AV2 decoding is roughly five times more complex than AV1 decoding. In practice, that means software running on today’s hardware will struggle to decode AV2 in real time without careful, architecture-specific optimization'

AV1 software decoding is already very intensive so AV2 decoding benchmarks are the next thing that would be really interesting (or mortifying) to see.

A codec spec isn't done until there is at least one decoder developed in the field. So reference + 1. The field implementations often become the de facto spec.

Reading the MPEG1 specs back in the 90s as a child opened my eyes to how to define complex systems. For a media coding standard, they spent most of their time saying how to interpret encoded bytes, which I realized is genius. Be descriptive about decoding and you don't have to be prescriptive about encoding. Encoding is where you can apply all the creativity, but you need to provide a way to have a shared understanding of the encoded bytes.

I thought this was about Dave2D

Seems like the blog succumbed to the HN hug of death (`Actioning this file would cause "jbkempf.com//blog/2026/dav2d/" to exceed the per-day file actions limit of 160000 actions, try again later`), is there a copy available somewhere?

  ... improvements around 25% compared to AV1

  AV2 decoding is roughly five times more complex than AV1 decoding

I'm not sure what these two lines mean or if we can compare them, any help?

> Make it fast on older desktop, by writing asm for SSSE3+ chips

I guess 5 years ago (around the time when Intel stopped making SSE-only chips) is technically "older", but I wouldn't prioritize avx2 when devices intended for consuming media definitely experience much less pressure to upgrade than workstations…

I would love to see comparisons with AV1 on very low bitrates.

Is codex working on novel decoders 24/7? I hope

Not to be confused with Da4vid (world-class hacker and owner of the Black sun) or D4vd (rap artist and alleged murderer)

D4vd

[dead]

Sorry if this sounds naive, but does it make sense to write a codec library in C/ASM considering how well Rust is progressing, especially when, as the author puts it, AV2 decoding is roughly five times more complex than AV1 decoding?

When AV1 was first announced, I got the impression the name was chosen partly as a pun/reference/homage to AVI, the classic but outdated format with used to be popular. Then when I saw Dav1d, OK, good way to continue the pun.

But now with AV2 and Dav2d, that completely breaks. Are we eventually going to get AV3/Dav3d and AV4/Dav4d, which will read like Ave/Daved and Ava/Davad? Seems a bit awkward. Was the idea from the start to have the 1 be the version number, and have it specifically be part of the name?

Ok whose idea was ‘Wiener filtering’

How is AV2 expected to avoid the patent-pool issues AV1 ran into?

AV1 was designed as royalty-free, but Sisvel’s pool and the recent Dolby/Snap proved the contrary.

https://accessadvance.com/2026/03/24/access-advance-licensor...

This seems like an interesting case to test AI agents on.

Like we had weird examples like C compilers and Bun. This is a much more interesting example because its highly nontrivial.

AV1 exists, Dav1d exists. Lets see AI take the AV2 spec and Dav1d code and try to make a working high performance AV2 decoder.