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Comment by blihp | Hacker News Reader

AV1 hardware encode just started rolling out with the most recent GPU architectures so the majority of hardware still has to do software encoding. I'd also guess that a very large fraction of the hardware out there doesn't even have hardware decode for AV1 since it was only the last generation of GPUs that got that. AV1 is mainly solving problems for the platform owners (google/netflix/facebook etc) and h264 will probably serve typical users for years to come especially if they have that one device they want to keep using that only supports h264.

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In the past (with h265 / h264 at least), hardware encoding always ended up with visibly worse quality (and often even bigger file sizes) compared to a software encoder like x264/x265.

Do you happen to know if that's still the case?

(I guess for use-cases such as live streaming it doesn't matter that much, but for video that ends up in some archive, it's probably less acceptable)

That's usually the case as the hardware encoders tend to make tradeoffs in the direction of lower transistor count / faster frame processing while software encoders have the luxury of going for higher quality.

It's around 5% (maybe 10%?) larger file sizes for same visual quality at the moment. For archival I think that's fine, as storage is cheap, it can still be a problem when you pay for outbound bandwidth to users.

hardware encoding gives up a little quality and filesize, but hardware encoding of AV1 will generally beat software encoding of X264 on all axes.

Yes, a YouTuber named EposVox released a video on AV1 hardware encoding when the first Intel dGPUs with support for it released: https://www.youtube.com/watch?v=ctbTTRoqZsM

Later on in the video, there are some graphs comparing Intel's AV1 encoder to SVT-AV1 at different speed presets. Even one of the faster presets (9) will comfortably stay above AV1 quality according to VMAF, and if you don't need real-time speeds you can lower the preset to get further ahead of the hardware encoder. (BTW: That video is >1 year old now, and SVT-AV1 had some significant updates in the meantime too. So the software side is probably looking better now.)

> I'd also guess that a very large fraction of the hardware out there doesn't even have hardware decode for AV1 since it was only the last generation of GPUs that got that

Don't underestimate dav1d. It's a highly optimized software AV1 decoder:

https://code.videolan.org/videolan/dav1d

On my nine year old system, 1080p60 AV1 video was unwatchable with early releases of dav1d due to too many dropped frames.

Eventually dav1d got enough AVX optimizations to play the same video on the same hardware with zero dropped frames.

It was an impressive demonstration of what can be achieved when software makes the most of the available hardware.

Yeah, it will still be a while before anyone can fully get away from h264, but with Apple adding AV1 decoders to their latest chips, hopefully all the wheels are at least in motion now.

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