Alliance for Open Media codecs

[nhw_pulsar]

Originally Posted by benwaggoner

It hasn't been trained on still images or HDR content or VVC style motion artifacts or AV1 grain synthesis

As I am only trained on still image artifacts, I am rather fascinated by people who talk about motion artifacts, as I have no knowledge on it.

So VVC has its own style of motion artifacts? If you have time, could you or another expert let us know if VVC style motion artifacts are visually more pleasant than AV1 motion artifacts for example?

Cheers,
Raphael

[benwaggoner]

Originally Posted by nhw_pulsar

As I am only trained on still image artifacts, I am rather fascinated by people who talk about motion artifacts, as I have no knowledge on it.

So VVC has its own style of motion artifacts? If you have time, could you or another expert let us know if VVC style motion artifacts are visually more pleasant than AV1 motion artifacts for example?

VVC has some really great tools to keep high QP inter prediction from revealing underlying block structure, which keeps highly compressed motion looking a lot more natural.

AV1 has some nice features in the same area as well, which provide good visible benefits at high compression ratios. I've not compared AV1 and VVC them in depth in this regard. It's kind of hard to separate any one tool out of the general codec and encoder alchemy*. Bit-for-bit, VVC is clearly a stronger codec than either AV1 or HEVC, although the ecosystem is still 1-2 years from broad deployment.

*A good 20+ years ago Touradj Ebrahimi told me that making a codec is "10% science, 20% alchemy, and 70% SUN worship."

In that we start with some good theory about how to get improvements with new tools, kind of mash them together in different ways and see what seems to work, and then simulate the heck of it to tune quant tables and symbols for optimum entropy coding and all that.

Obviously, that was from a post MPEG-4 part 2, pre H.264, SPARC for high performance compute era. But still some deep truths in there. Today it'd be machine learning instead of SUN worship.

[megalol]

Originally Posted by Jamaika

GCC 11.3.1 20221229 without _GLIBCXX_HAS_GTHREADS, SIMD AVX
libavif 0.11.1.0-62f8095 / libwebp-->avif b80553d (aom v3.5.0-9c91575, svt-av1 1.4.1-ad82cde) / libheif-->avif 96a114f (aom v3.5.0-9c91575, svt-av1 1.4.1-ad82cde)
https://www.sendspace.com/file/4kd4ud

Hi, thanks, useful tools but its has very big problem that converted to avif webp images with av1enc_avx.exe looks much darker (tried with older version posted here also and different settings). If I do the same with libvips or imagemagick for example then it has the same brightness.

[foxyshadis]

Originally Posted by megalol

Hi, thanks, useful tools but its has very big problem that converted to avif webp images with av1enc_avx.exe looks much darker (tried with older version posted here also and different settings). If I do the same with libvips or imagemagick for example then it has the same brightness.

av1enc is a gstreamer test application that assumes a number of properties that often don't apply to images. If you think it should, report the error to gstreamer. (But I'm pretty sure I've seen this in their tracker.) I wouldn't touch it with a six-foot pole for avif, even if it's great for streaming and playback.

avifenc or heifenc are proper image encoders that offer the full suite of detection and override options. libvips and ImageMagick both use libheif, though in a different way than these command-line tools.

[megalol]

Originally Posted by foxyshadis

av1enc is a gstreamer test application that assumes a number of properties that often don't apply to images. If you think it should, report the error to gstreamer. (But I'm pretty sure I've seen this in their tracker.) I wouldn't touch it with a six-foot pole for avif, even if it's great for streaming and playback.

avifenc or heifenc are proper image encoders that offer the full suite of detection and override options. libvips and ImageMagick both use libheif, though in a different way than these command-line tools.

I wouldn't use av1enc either if there would be direct webp->avif support in avifenc because I agree that its best tool for avif.

[LigH]

New uploads: (MSYS2; MinGW32 / MinGW64: GCC 12.2.0)

AOM _v3.6.0-252-gdfbaa9891

rav1e 0.6.1-4-gf178e97

dav1d 1.1.0-0-g9593e62

SVT-AV1 v1.4.1-79-gaef9ee9e

avif 0.11.1-86d66f0
dav1d [dec]:1.1.0-0-g9593e62, aom [enc/dec]:3.6.0-252-gdfbaa9891, rav1e [enc]:0.6.1 (p20230214-4-gf178e97)

[hajj_3]

Youtube is adding AV1 livestream uploading using RTMP+ - https://www.tomshardware.com/news/av...ing-to-youtube