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.