Fascinating, thank you for this analysis! Currently pining for release of an updated Apple TV, which will have an SoC capable of hardware AV1 decode.
It'd be great to hear from someone at Netflix about the unexpected Bojack Horseman results. I'd bet that Netflix just isn't yet taking advantage of AV1 features designed especially for this kind of animation and synthetic content.
I feel like this was copy edited by ChatGPT and it really grates me. I couldn’t help but lose focus after I started seeing telltale signs of AI.
While the topic matter is interesting, I feel like obviously synthetic content falls into the “that which was not worth writing, is not worth reading either” trap.
If the authors tone is extremely ChatGPT-esque, I apologize in advance.
Was once out in a remote area on an 800 kbps DSL connection. YouTube couldn't stream, Prime Video couldn't stream. Netflix worked fine. Years later, I remain impressed at their uniqueness.
Okay, so AV1 has lower bitrate. I can encode any video format at arbitrary bitrates, but that metric is not useful on its own. An article about how AV1 requires less bits for the same or improved perceptual quality would have been far more interesting.
> Device Support: Hardware decoding for AV1 isn’t on every device yet.
By now - it should be in most devices that's aren't outdated by even average standards. And it's worth mentioning that for devices that don't have hardware decoding, dav1d does an excellent job of decoding it on the CPU.
The problem is more with hardware encoding. That's indeed only present in only recent generations (or a couple) of hardware and even with that, AMD for example have an aspect ratio limitation bug in their AV1 hardware encoder (which requires adding black bands to work around) that's only fixed in RDNA 4 which is not available in their APUs, so it won't be fixed in APUs until their UDNA is used for them (they didn't fix it in RDNA 3.5 chips).
Interesting charts, but this is all completely meaningless without image quality comparisons. I can easily use 50% less bandwidth than Netflix's H264 streams as well, with H264 even, by just cranking up the compression & dropping the bitrate.
Presumably nothing jumped out at the author as being worse, but come on how can you have a whole section on why AV1's regression on Bojack is actually a good thing because the quality is way higher, and then not show any quality comparisons?
Very good read, love some of the humor in this article. It helped me get through to the end!!
Also, If anyone was wondering where AV1 stands in comparison to VP8 and VP9... I just looked it up after a few years of not paying attention and I guess Google donated VP8 and VP9 to the alliance for open media foundation (AOMedia) in 2015 and they created AV1 and released it in 2018.
For mobile, I don't know who outside of Netflix is delivering AV1. If they are, I expect them to be leveraging the hardware AV1 decoders for battery life instead of employing a software only solution like dav1d. Saying that, I think Netflix was using dav1d solution where it had a benefit (e.g. low quality cellular networks)
Perhaps the most important question which I have yet to see anyone pointing out. Those bit rate numbers are appalling! 2-4Mbps average bitrate? For a services you are paying for? I knew Netflix has gotten bad but this is worse than I thought. Even some high end YouTube Content does better than that. It should be 8Mbps minimum. And at this bitrate the difference between H.264 and AV1 wont be so obvious.
>Those bit rate numbers are appalling! 2-4Mbps average bitrate?
While those may sound low, what I'm thinking is Netflix didn't see any benefit in perceptual quality (or VMAF scores) but sending more bits down the pipe and increasing their bandwidth bill.
18 comments
[ 5.3 ms ] story [ 53.5 ms ] threadIt'd be great to hear from someone at Netflix about the unexpected Bojack Horseman results. I'd bet that Netflix just isn't yet taking advantage of AV1 features designed especially for this kind of animation and synthetic content.
While the topic matter is interesting, I feel like obviously synthetic content falls into the “that which was not worth writing, is not worth reading either” trap.
If the authors tone is extremely ChatGPT-esque, I apologize in advance.
By now - it should be in most devices that's aren't outdated by even average standards. And it's worth mentioning that for devices that don't have hardware decoding, dav1d does an excellent job of decoding it on the CPU.
The problem is more with hardware encoding. That's indeed only present in only recent generations (or a couple) of hardware and even with that, AMD for example have an aspect ratio limitation bug in their AV1 hardware encoder (which requires adding black bands to work around) that's only fixed in RDNA 4 which is not available in their APUs, so it won't be fixed in APUs until their UDNA is used for them (they didn't fix it in RDNA 3.5 chips).
Presumably nothing jumped out at the author as being worse, but come on how can you have a whole section on why AV1's regression on Bojack is actually a good thing because the quality is way higher, and then not show any quality comparisons?
Also, If anyone was wondering where AV1 stands in comparison to VP8 and VP9... I just looked it up after a few years of not paying attention and I guess Google donated VP8 and VP9 to the alliance for open media foundation (AOMedia) in 2015 and they created AV1 and released it in 2018.
For mobile, I don't know who outside of Netflix is delivering AV1. If they are, I expect them to be leveraging the hardware AV1 decoders for battery life instead of employing a software only solution like dav1d. Saying that, I think Netflix was using dav1d solution where it had a benefit (e.g. low quality cellular networks)
https://netflixtechblog.com/netflix-now-streaming-av1-on-and...
Perhaps the most important question which I have yet to see anyone pointing out. Those bit rate numbers are appalling! 2-4Mbps average bitrate? For a services you are paying for? I knew Netflix has gotten bad but this is worse than I thought. Even some high end YouTube Content does better than that. It should be 8Mbps minimum. And at this bitrate the difference between H.264 and AV1 wont be so obvious.
>Those bit rate numbers are appalling! 2-4Mbps average bitrate?
While those may sound low, what I'm thinking is Netflix didn't see any benefit in perceptual quality (or VMAF scores) but sending more bits down the pipe and increasing their bandwidth bill.
VMAF is better than SSIM PSNR but it is still far from perfect. And it is a reason why most torrent are still using HEVC and AVC.