'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.
> AV1 software decoding is already very intensive so AV2 decoding benchmarks are the next thing that would be really interesting (or mortifying) to see.
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was first announced, I got the impression the name was chosen partly as a pun/reference/homage to AVI, the classic but outdated format with used to be popular.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?
I understood it as compression is 25% better : a quality of 10mbps in av1 can be achieved with 8mbps in Av2.
But, it needs 5 times more compute power for this 25% gain.
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?
That isn’t particularly helpful to someone asking a question in good faith. What others are using doesn’t clarify why they are using it. Plus, FFmpeg is itself a decade older than Rust. The OP is asking about starting a new project today.
The algorithms deployed in these kind of codecs take into account not only human vision and mathematical laws of information, but also nitty-gritty details of how computers work, which are optimally exploited by directly having humans write detailed assembly rather than a compiler make a best guess and effort.
Encoder and decoder writers frequently need extremely fine grain control over SIMD instructions in order to get good performance.
The way they weave these instructions can be very hard to express with a high level language.
Further, there's a ton of work with arrays and importantly parts of arrays. They can, for example, need to extract every other element up to 1/2 the array. Unfortunately, rust has runtime array bounds checks which make writing that sort of code slower. The compiler can elade those checks, but usually only in simple cases.
The authors would be writing a bunch of unsafe rust to get the performance they want and rust makes that more painful on purpose.
I like rust, but C/ASM really is the right choice here. This is one of the few cases where rust's safety is a major detriment.
They filed a suit, henceforth making a claim of an issue...... They haven't "proved" anything other then they have lawyers on staff that can file some paperwork until the suit is settled in court...
Sisvel allows you to pay them if you believe their claims, they haven't actually taken anyone not paying to court yet to prove that. The only court cases for VP9/AV1 from Sisvel so far have been their patents being found invalid/irrelevant.
Dolby is somewhat more interesting in that rather than scare tactics, media hype, and attempting to form a pool about it they are actually taking a patent assertion claim to court.
Every single AV2 news here in the last week has seen exactly the same question.
Either go back read the answers there first, or I will assume you are part of a FUD campaign (yes, I know HN guidelines, but again every single AV2 news in the last week has seen the same rhetorical "questions" as top "comments").
'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.
> AV1 software decoding is already very intensive so AV2 decoding benchmarks are the next thing that would be really interesting (or mortifying) to see.
Yes, this is going to be fun to watch.
I came to post this as well. Until widespread, inexpensive hardware catches up to a 2018 codec, AV# will remain a niche ideal.
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?
> experience Dav... Now in 3D!
I'm not sure what these two lines mean or if we can compare them, any help?
Smaller files but harder to decode
> I'm not sure what these two lines mean or if we can compare them, any help?
AV2 saves 25% bandwidth at the cost of 5x more decoding complexity.
I understood it as compression is 25% better : a quality of 10mbps in av1 can be achieved with 8mbps in Av2. But, it needs 5 times more compute power for this 25% gain.
I thought this was about Dave2D
[delayed]
Is codex working on novel decoders 24/7? I hope
I would love to see comparisons with AV1 on very low bitrates.
Return of the 8MB Shrek encodes?
https://web.archive.org/web/20210416200451/https://cdn.disco...
Shrek 1 at 8.34MB including audio.. insane
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?
Because it's 5 times more complex, you need to get the maximum performance available. Therefore more ASM than ever.
Rust does not bring more performance. Just more safety.
Go ask FFmpeg what they're writing their encoders and decoders in.
That isn’t particularly helpful to someone asking a question in good faith. What others are using doesn’t clarify why they are using it. Plus, FFmpeg is itself a decade older than Rust. The OP is asking about starting a new project today.
Yes? There is 5x more code to optimize the ASM for.
The algorithms deployed in these kind of codecs take into account not only human vision and mathematical laws of information, but also nitty-gritty details of how computers work, which are optimally exploited by directly having humans write detailed assembly rather than a compiler make a best guess and effort.
Encoder and decoder writers frequently need extremely fine grain control over SIMD instructions in order to get good performance.
The way they weave these instructions can be very hard to express with a high level language.
Further, there's a ton of work with arrays and importantly parts of arrays. They can, for example, need to extract every other element up to 1/2 the array. Unfortunately, rust has runtime array bounds checks which make writing that sort of code slower. The compiler can elade those checks, but usually only in simple cases.
The authors would be writing a bunch of unsafe rust to get the performance they want and rust makes that more painful on purpose.
I like rust, but C/ASM really is the right choice here. This is one of the few cases where rust's safety is a major detriment.
Ok whose idea was ‘Wiener filtering’
Norbert Wiener in the 1940s. He invented the technique.
It's a semi-common last name.
https://en.wikipedia.org/wiki/Wiener_filter?wprov=sfla1
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...
They filed a suit, henceforth making a claim of an issue...... They haven't "proved" anything other then they have lawyers on staff that can file some paperwork until the suit is settled in court...
How does that prove anything?
They're claiming that there are patents, but that doesn't mean there are.
Dolby is only the most recent case, Sisvel consorsium actually bills licences per device:
Consumer Display Device: EUR 0.32
Consumer Non-Display Device: EUR 0.11
(source here: https://www.sisvel.com/licensing-programmes/audio-and-video-...)
That doesn’t prove their claims are valid.
I can claim the same and offer licenses per device.
How does how they bill for their product, matter in terms of if their lawsuit holds merit?
Can you point to any other patent lawsuit over AV1? AFAIK the Dolby case is the first.
Sisvel allows you to pay them if you believe their claims, they haven't actually taken anyone not paying to court yet to prove that. The only court cases for VP9/AV1 from Sisvel so far have been their patents being found invalid/irrelevant.
Dolby is somewhat more interesting in that rather than scare tactics, media hype, and attempting to form a pool about it they are actually taking a patent assertion claim to court.
No codec can ever avoid patent-pool claims.
Every single AV2 news here in the last week has seen exactly the same question.
Either go back read the answers there first, or I will assume you are part of a FUD campaign (yes, I know HN guidelines, but again every single AV2 news in the last week has seen the same rhetorical "questions" as top "comments").