
SVT-AV1: open-source AV1 encoder and decoder - CharlesW
https://netflixtechblog.com/svt-av1-an-open-source-av1-encoder-and-decoder-ad295d9b5ca2
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sho_hn
No further mention of rav1e from Mozilla/Xiph/Vimeo, which seems like the more
relevant benchmark comparison than libaom.

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clouddrover
Why? rav1e doesn't yet achieve the same quality as libaom.

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ComputerGuru
I definitely got better quality with rav1e than libaom (via ffmpeg), before I
gave up on the latter altogether.

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clouddrover
Here are some measured results. rav1e is worse than libaom and SVT-AV1:

[https://www.reddit.com/r/AV1/comments/f1h2u1/aom_vs_rav1e_vs...](https://www.reddit.com/r/AV1/comments/f1h2u1/aom_vs_rav1e_vs_svtav1_vs_x265_vs_vp9_vs_svtvp9/)

[https://forum.doom9.org/showthread.php?p=1893776#post1893776](https://forum.doom9.org/showthread.php?p=1893776#post1893776)

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ComputerGuru
Perhaps things have improved for libaom since the last time I tried it but my
issue wasn’t overall quality so much as sections of videos that had way too
many very much visible artifacts (to me it looked like there were likely bugs
rather than a poor design).

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clouddrover
YouTube is using libaom for its many, many AV1 encodes. Without knowing the
version you used or the settings you used there isn't much that can be
usefully talked about. What we can say is that libaom is good enough to be
used on the world's biggest video website.

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AndrewUnmuted
I agree with the OP’s assessment - as recently as two weeks ago, Libaom was
too slow to even do quality testing on real footage. And that’s with forty
modern Xeon cores.

The fact that YouTube uses it only proves the increasingly obvious business
model they use in the space, namely the monopolization of the encoding
ecosystem by literally throwing away money to steer people clear of rav1e.

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clouddrover
The practical reality is that libaom is benchmarked against routinely. It is
the benchmark.

See some benchmarks here:

[https://videocodectracker.dev/](https://videocodectracker.dev/)

[https://arewecompressedyet.com/](https://arewecompressedyet.com/)

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dabei
AV1 Encoding is ready for prime time. However hardware decoder is mostly
absent, which blocks adoption in mobile apps. (Dav1d is great, but consumes
too much power on mobile devices)

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jjcm
The encoding still isn't ready for user driven content sites. It's still too
slow, even with the 16% savings shown with the new improvements this article
talks about. For Netflix it's great as they have a significant amount of time
before content goes live (weeks if not months), but for sites like
youtube/vimeo/instagram/etc, it just isn't quite there yet. The turnaround
time is simply too long.

That's just the UX bottleneck, but there's another elephant in the room: it's
cost prohibitive. Encoding time is so slow that we're still measuring in
frames per minute for most software encoders. If I want to move my whole video
encoding pipeline to AV1 from h264, I need around 100x the horsepower to
encode. That's 100x the server costs, and as someone who's looking heavily at
using AV1 for the video site I'm working on now, it's simply cost prohibitive.

Don't get me wrong, the steps that Netflix are taking with SVT-AV1 are
amazing. We're seeing a huge improvement from the 500x vs h264 it was showing
last year, but it still needs a huge amount of effort before it's ready for
prime time. I'm really hoping we see some early hardware encoding/decoding
implementations for AV1 given the number of companies who are in support of
it.

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clouddrover
> _The encoding still isn 't ready for user driven content sites._

YouTube has lots of AV1 encodes. You've probably watched AV1 encoded content
without realising it. Here are a few of examples. To verify that they're AV1
encoded, right-click on the video and select "Stats for Nerds". I'm playing
them in Firefox 75 beta.

Halo trailer: [https://www.youtube.com/watch?v=Fmdb-
KmlzD8](https://www.youtube.com/watch?v=Fmdb-KmlzD8)

Despacito music video:
[https://www.youtube.com/watch?v=kJQP7kiw5Fk](https://www.youtube.com/watch?v=kJQP7kiw5Fk)

Porsche Taycan commercial:
[https://www.youtube.com/watch?v=92sXWVxRr0g](https://www.youtube.com/watch?v=92sXWVxRr0g)

For some videos YouTube has AV1 encodes up to 480p, others are up to 1080p,
and some are up to 4K.

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fireattack
Any reason why YouTube only uses it for low(er) resolutions?

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clouddrover
The YouTube video library is huge so they're prioritizing encodes based on
encode time (AV1 takes longer to encode), the ability to play it (more systems
can play 480p AV1 than can play 4K AV1), and the number of views a video gets
(if a video has a low view count then it doesn't much matter what it's encoded
in).

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codelord
Why does Netflix publish articles on paywalled websites? Are they aware that
users need to pay Medium to read their articles? I get this error: "You’ve
reached the end of your free member preview for this month. Become a member
now for $5/month to read this story and get unlimited access to all of the
best stories on Medium."

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encom
>Why does Netflix publish articles on paywalled websites?

Maybe nobody there can figure out how to set up a web server? Maybe they get a
kickback from Medium subscriptions? So many questions.

You can usually bypass the paywall with the archiver:
[https://archive.ph/gv8T6](https://archive.ph/gv8T6)

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mekster
> Maybe nobody there can figure out how to set up a web server?

Huh? It's their business for sake.

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e12e
Nice.

> For estimating encoding times, we used Intel(R) Xeon(R) Platinum 8170 CPU @
> 2.10GHz machine with 52 physical cores and 96 GB of RAM, with 60 jobs
> running in parallel.

Would love to see some comparisons with amd, at some point.

Is there currently an easy way to run this on multiple machines? Back in the
day, I'd probably try a single image cluster, like openmosix - but I'm not
aware of anything similar for modern setups - neither self-host or "hardware
on tap"?

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clouddrover
> _Would love to see some comparisons with amd_

Here are some comparisons of various SVT-AV1 releases on Intel and AMD CPUs:

[https://openbenchmarking.org/showdown/pts/svt-
av1](https://openbenchmarking.org/showdown/pts/svt-av1)

~~~
e12e
Thanks. Nice to see 60fps 1080p is within reach for certain profiles. Anyone
know how big the difference is up to 4k for typical video? Is it more or less
than 4x?

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ksec
>The results are presented for 1-pass mode with fixed frame-level QP offsets.
A single-threaded compression mode is used.

Why is it 1-Pass? and if I may, use the word "again". Every time when it is
compared to LibAOM, it is always one pass.

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clouddrover
There's a 2 pass comparison in the article. The graph comes from their
comparison site which uses 2 pass encoding for both SVT-AV1 and libaom:

[https://videocodectracker.dev/](https://videocodectracker.dev/)

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mstade
Seeing the title I thought this was something developed by the Swedish public
service broadcasting company SVT, which also has a pretty extensive online
streaming service and so it wouldn't be too far fetched an idea that they
might work on something like this. Finally – I thought – taxpayer money being
out to good use.

Anyway, cool tech, well done! Hope it takes off and hardware encoders/decoders
start to become common place as well.

