
AV1 codec ecosystem update - singhkays
https://www.singhkays.com/blog/av1-ecosystem-update-may-2019/
======
ComputerGuru
> Auorara claims to improve encoding speed by 32.2% against x265 veryslow

I'll have to see it to believe it, because av1 has a _long_ way to go to
become even remotely comparable to x265 in encode times, let alone superior.

With ffmpeg built from git, I can encode a 1920x1080 video file to x265 (with
a boatload of parameters and options, via a custom threadpool I've written
that can saturate all the cores regardless of input stream complexity or size)
at 9.2fps on a 16-core 1950X with sufficient RAM.

The same harness powering ffmpeg's av1 encoder (not the fastest, they haven't
switched to rav1e yet) does not manage 2fps (I'm letting it run to see what it
ends up with, but it'll be a while for this short 3:13 video).

~~~
FullyFunctional
First, this is still the dawn of AV1 and the encoder you should be watching is
SVT-AV1. You cannot conclude anything about the ultimate of AV1 encoding speed
from experiences with a current version of ffmpeg.

As long as AV1 encoding (at useful compression etc) is within a small factor
of HVEC, it will not be a factor in its success. License, quality,
compression, and decoding speed are the things that matter.

~~~
shmerl
And how is rav1e doing? The description claims it to be "the fastest and
safest AV1 encoder."

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motbob
>Company, which has every reason to exaggerate, claims it can improve encoding
speed by 32.2% against x265 veryslow

"It’ll be interesting to see if we find out more info and are able to test
this encoder in the coming months."

>BBC, which has no skin in the game, claims AV1 is less efficient than HEVC

"I would call this test flawed as AV1 has consistently shown to perform better
than HEVC."

Every article on AV1 that I have read is like this, except for
[https://codecs.multimedia.cx/2018/12/why-i-am-sceptical-
abou...](https://codecs.multimedia.cx/2018/12/why-i-am-sceptical-about-av1/)
\-- they are always blatantly cheerleading new advancements, like only being
5x slower to decode than VP9 or 10x slower to encode than x265 or whatever.
But the advancements are not phrased like that, of course--you are never
reminded that the competition continues to clobber AV1 in every aspect but
filesize/quality efficiency.

~~~
microcolonel
> _BBC, which has no skin in the game, claims AV1 is less efficient than HEVC_

The BBC does have skin in the game. They have many people in house who have
invested in HEVC, and put their names behind that decision; furthermore, maybe
you'll remember when the BBC spent a huge amount of money on Dirac, which
seems to have continued to be extremely impractical in the medium to long
term. Maybe the BBC doesn't have a spectacular track record for picking the
winners in the video codec game. ;- )

Added: The BBC's comparison also seems to be between professionally-configured
and tuned HEVC/VVC encoders, supported by their vendors; and what seems to be
a default-configured libaom, with no consultation with the vendor.

~~~
derf_
To be fair, BBC's sole reason for investing in Dirac (to my understanding) was
to fit HD quality video into the pipes for an SD production system. As far as
I know, it satisfied that purpose for them, so the project can be considered a
success from that standpoint.

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slimscsi
>From Visionular website, Auorara claims to improve encoding speed by 32.2%
against x265 veryslow

This is extremely unlikely. But a game changer if true.

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chubs
Any ideas how this Intel encoder compares to rav1e and why they chose to roll
their own?

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phkahler
So the Intel encoder handles 128x128 blocks. Isn't AV1 limited to 64x64
blocks?

~~~
sp332
"superblocks... can either be of size 128×128 or 64×64 pixels"
[https://en.wikipedia.org/wiki/AV1#Partitioning](https://en.wikipedia.org/wiki/AV1#Partitioning)
Unfortunately I don't know of a more authoritative source.

~~~
cesarb
> Unfortunately I don't know of a more authoritative source.

[https://aomediacodec.github.io/av1-spec/av1-spec.pdf](https://aomediacodec.github.io/av1-spec/av1-spec.pdf)
is the most authoritative source.

"All superblocks within a frame are the same size and are square. The
superblocks may be 128x128 luma samples or 64x64 luma samples. A superblock
may contain 1 or 2 or 4 mode info blocks, or may be bisected in each direction
to create 4 sub-blocks, which may themselves be further subpartitioned,
forming the block quadtree."

"use_128x128_superblock, when equal to 1, indicates that superblocks contain
128x128 luma samples. When equal to 0, it indicates that superblocks contain
64x64 luma samples. (The number of contained chroma samples depends on
subsampling_x and subsampling_y.)"

