5 ms·

'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

by jordand 5mo ago

'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.

jbk 5mo ago
> 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.
mrbluecoat 5mo ago
I came to post this as well. Until widespread, inexpensive hardware catches up to a 2018 codec, AV# will remain a niche ideal.
- breve 5mo ago
  Hardly niche. My laptop isn't new and it has hardware AV1 decoding and encoding. My 10 year old iPhone 7 can play 1080p AV1 video in software for over 200 minutes with VLC. The iPhone 7 was released in 2016, a year and a half before AV1. The dav1d decoder is mighty. Netflix uses AV1: https://netflixtechblog.com/av1-now-powering-30-of-netflix-streaming-02f592242d80 https://netflixtechblog.com/av1-now-powering-30-of-netflix-s... YouTube uses AV1. It's tough to be more mainstream than that. Right click on a YouTube video and select Stats for Nerds. If your system is capable of it, chances are it will be playing back in AV1. Most of the YouTube videos I watch these days are AV1 encodes. Sometimes it's in VP9 and occasionally it's H.264.
  - sylware 5mo ago
    Same. Mostly AV1, sometimes VP9, and rarely h264. What's missing mostly: live streams which are h264. Currently, and I say currently, dav1d is so fast, no worries on that side.
  - weiliddat 5mo ago
    Supported is different from doing it well though. You do notice the performance hit even on TVs that playback YouTube videos on AV1. Even on 1080p videos running on AV1 on 1x, the TV system bogs down and any kind of interaction has a variable 1-3s lag. On some TVs if you do 1.25x the TV automatically "downgrades" the resolution to 480p to avoid dropping frames. I wish there was an option to still use VP9 / H.264 on those systems (even limited to 1080p).
    - Dylan16807 5mo ago
      More reason to never use the builtin stuff in a tv. Cheap sticks can handle decoding fine.
    - TingPing 5mo ago
      Youtube artificially limits the resolution, on mine if you cast the exact same video it doesn’t impose that limit and works fine.
    - Gigachad 5mo ago
      My TV lags out even when doing nothing. So I use it as a dumb panel and let another device handle the streaming and decoding. Also has the benefit of blocking LG from loading adverts all over the UI.
  - jordand 5mo ago
    Yeah I could imagine the AV1 codec sticking around for a very long while, even as a fallback for AV2. There's still hundreds of millions of people out there using old/cheap devices (especially in developing countries) where that battery drain from software decoding is a big problem, so AV2 would be nonviable.
    - ZeroGravitas 5mo ago
      Some of the early use of VP9 and AV1 was Netflix serving video to people in developing countries. Their metered bandwidth was more of a bottleneck than the CPU playback.
kmfrk 5mo ago
Intel's Arc dGPUs were really compelling for dedicated AV1 encode and decode, especially the small form factor of some cards. You could even fit it as a secondary card in a PC dedicated to recording and encode workflows for OBS. Hope we get a similar option with future lineups that support AV2, especially given how popular video creation and streaming are now.
- thrownthatway 5mo ago
  Is there a compelling reason encoding needs to be done locally? The point of encoding is to reduce downstream bandwidth for the viewer, and upstream bandwidth for the distribution network. The content creator only needs to upload it once.
  - halJordan 5mo ago
    Well yes? The platforms only accept certain resolution/bitrates and also most of America isnt running 1gig up. They're running 5-30 mbps up. So yeah they need to encode it.
    - thrownthatway 5mo ago
      > They're running 5-30 mbps up Do you not have 98% high speed 5G coverage?
      - ihattendorf 5mo ago
        Data caps make that hard. While everyone likes to claim unlimited data, I'm not aware of any providers that don't have a heavy data user clause where they'll deprioritize your data if you're a top ~5% data user (usually somewhere over ~1TB/month). You also will need _some_ sort of encoding locally before uploading, even if it's minimal, which could lead to issues when encoded again (although there are codecs available to minimize this).
      - Forgeties79 5mo ago
        Just over half the world’s smartphone users do (meaning almost half don’t), and certain countries/areas have way more coverage than others. And a massive number of people have limited data per month, which means it’s also a cost concern. Leaner delivery is not just ethical, but it also makes better business sense.
nwallin 5mo ago
> AV1 software decoding is already very intensive I think you might be misunderestimating how incredible the dav1d AV1 decoder is. Not only does it require less total time than the reference decoder to decode the same video, but it can spread that out over far more threads. I was unable to watch 4k 60fps av1 video on my media center PC (it's from 2019, so predates hardware av1 decoding, and, well, the CPU was a little long in the tooth) until I switched to dav1d. With dav1d I am now able to watch 4k 60fps av1 using software decoding, and my machine uses 10% CPU while doing so. Really amazing piece of software. With any luck, the dav2d 5x claim will hold true, and 10% CPU usage will scale to 50% CPU usage, meaning I'm still able to watch 4k 60fps video on my media center without a hardware upgrade. (that machine doesn't have hyperthreading, so 50% cpu is actually 50%, not 100% in a fancy suit)
- rbultje 5mo ago
  dav2d author here - the 5x number is just where we currently are, it's not the theoretical limit. We're hopeful that a significant amount of the increase we observe in dav2d relative to dav1d is in math code, which should be easier to optimize using hand-written assembly or other algorithmic optimizations. If that holds true, the practical slowdown once everything has been optimized may be substantially less, possibly 2x.

by jordand 5mo ago

jbk 5mo ago

> 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.

mrbluecoat 5mo ago

I came to post this as well. Until widespread, inexpensive hardware catches up to a 2018 codec, AV# will remain a niche ideal.

breve 5mo ago
Hardly niche. My laptop isn't new and it has hardware AV1 decoding and encoding. My 10 year old iPhone 7 can play 1080p AV1 video in software for over 200 minutes with VLC. The iPhone 7 was released in 2016, a year and a half before AV1. The dav1d decoder is mighty. Netflix uses AV1: https://netflixtechblog.com/av1-now-powering-30-of-netflix-streaming-02f592242d80 https://netflixtechblog.com/av1-now-powering-30-of-netflix-s... YouTube uses AV1. It's tough to be more mainstream than that. Right click on a YouTube video and select Stats for Nerds. If your system is capable of it, chances are it will be playing back in AV1. Most of the YouTube videos I watch these days are AV1 encodes. Sometimes it's in VP9 and occasionally it's H.264.
- sylware 5mo ago
  Same. Mostly AV1, sometimes VP9, and rarely h264. What's missing mostly: live streams which are h264. Currently, and I say currently, dav1d is so fast, no worries on that side.
- weiliddat 5mo ago
  Supported is different from doing it well though. You do notice the performance hit even on TVs that playback YouTube videos on AV1. Even on 1080p videos running on AV1 on 1x, the TV system bogs down and any kind of interaction has a variable 1-3s lag. On some TVs if you do 1.25x the TV automatically "downgrades" the resolution to 480p to avoid dropping frames. I wish there was an option to still use VP9 / H.264 on those systems (even limited to 1080p).
  - Dylan16807 5mo ago
    More reason to never use the builtin stuff in a tv. Cheap sticks can handle decoding fine.
  - TingPing 5mo ago
    Youtube artificially limits the resolution, on mine if you cast the exact same video it doesn’t impose that limit and works fine.
  - Gigachad 5mo ago
    My TV lags out even when doing nothing. So I use it as a dumb panel and let another device handle the streaming and decoding. Also has the benefit of blocking LG from loading adverts all over the UI.
- jordand 5mo ago
  Yeah I could imagine the AV1 codec sticking around for a very long while, even as a fallback for AV2. There's still hundreds of millions of people out there using old/cheap devices (especially in developing countries) where that battery drain from software decoding is a big problem, so AV2 would be nonviable.
  - ZeroGravitas 5mo ago
    Some of the early use of VP9 and AV1 was Netflix serving video to people in developing countries. Their metered bandwidth was more of a bottleneck than the CPU playback.

kmfrk 5mo ago

Intel's Arc dGPUs were really compelling for dedicated AV1 encode and decode, especially the small form factor of some cards. You could even fit it as a secondary card in a PC dedicated to recording and encode workflows for OBS. Hope we get a similar option with future lineups that support AV2, especially given how popular video creation and streaming are now.

thrownthatway 5mo ago
Is there a compelling reason encoding needs to be done locally? The point of encoding is to reduce downstream bandwidth for the viewer, and upstream bandwidth for the distribution network. The content creator only needs to upload it once.
- halJordan 5mo ago
  Well yes? The platforms only accept certain resolution/bitrates and also most of America isnt running 1gig up. They're running 5-30 mbps up. So yeah they need to encode it.
  - thrownthatway 5mo ago
    > They're running 5-30 mbps up Do you not have 98% high speed 5G coverage?
    - ihattendorf 5mo ago
      Data caps make that hard. While everyone likes to claim unlimited data, I'm not aware of any providers that don't have a heavy data user clause where they'll deprioritize your data if you're a top ~5% data user (usually somewhere over ~1TB/month). You also will need _some_ sort of encoding locally before uploading, even if it's minimal, which could lead to issues when encoded again (although there are codecs available to minimize this).
    - Forgeties79 5mo ago
      Just over half the world’s smartphone users do (meaning almost half don’t), and certain countries/areas have way more coverage than others. And a massive number of people have limited data per month, which means it’s also a cost concern. Leaner delivery is not just ethical, but it also makes better business sense.

nwallin 5mo ago

> AV1 software decoding is already very intensive I think you might be misunderestimating how incredible the dav1d AV1 decoder is. Not only does it require less total time than the reference decoder to decode the same video, but it can spread that out over far more threads. I was unable to watch 4k 60fps av1 video on my media center PC (it's from 2019, so predates hardware av1 decoding, and, well, the CPU was a little long in the tooth) until I switched to dav1d. With dav1d I am now able to watch 4k 60fps av1 using software decoding, and my machine uses 10% CPU while doing so. Really amazing piece of software. With any luck, the dav2d 5x claim will hold true, and 10% CPU usage will scale to 50% CPU usage, meaning I'm still able to watch 4k 60fps video on my media center without a hardware upgrade. (that machine doesn't have hyperthreading, so 50% cpu is actually 50%, not 100% in a fancy suit)

rbultje 5mo ago
dav2d author here - the 5x number is just where we currently are, it's not the theoretical limit. We're hopeful that a significant amount of the increase we observe in dav2d relative to dav1d is in math code, which should be easier to optimize using hand-written assembly or other algorithmic optimizations. If that holds true, the practical slowdown once everything has been optimized may be substantially less, possibly 2x.