AV1@Scale: Film Grain Synthesis, The Awakening

To the comments hating on grain: everything naturally has some amount of noise or grain - even the best digital sensors. Heck, even your eyes do. It's useful beyond just aesthetics. It tends to increase perceived sharpness and hides flaws like color banding and compression artifacts.

That's not to say that all noise and grain is good. It can be unavoidable, due to inferior technology, or a result of poor creative choices. It can even be distracting. But the alternative where everything undergoes denoising (which many of our cameras do by default now) is much worse in my opinion. To my eyes, the smoothing that happens with denoising often looks unrealistic and far more distracting.

My issue is that grain is good based on the creative decisions of the creators of the content. It is not something that a group of nerds compressing 1s and 0s should be making

I agree. However, let's look at it practically. Let's assume someone is watching content streamed on a low bandwidth connection. As a content creator, what version of the compressed content would you rather your audience experience:

a) Compressed original with significant artifacts from the codec trying to represent original grain

b) A denoised version with fewer compression artifacts, but looks "smoothed" by the denoising

c) A denoised version with synthesized grain that looks almost as good as the original, though the grain doesn't exactly match

I personally think the FGS needs better grain simulation (to look more realistic), but even in its current state, I think I'd probably go with choice C. I'm all for showing the closest thing to the author's intent. We just need to remember that compression artifacts are not the author's intent.

In an ideal world where we can deliver full, uncompressed video to everyone, then obviously - don't mess with it at all!

For content that we're concerning ourselves with this level of detail, I'd prefer the old iTunes method of prefetching the file and not stream it. For typical YT content, streaming is fine. For typical sitcom or other content, streaming is fine. For something like a feature that I'm so concerned about the details of grain, I have no problem downloading to play a local version. No, not a torrent.

Case in point: the HBO into animation. It uses static from the old analog days. It looks like shit even at 4k because random noise is impossible to compress without the exact strategy outlined here (stripping it out and rendering it later).

We live in a world of resource constraints. The nerds compressing 1s and 0s are very much concerned about creative intent. They noticed that compression wrecks that creative intent and wanted to better communicate it in a world with bandwidth limitations.

Grain in state of the art digital sensors is nothing compared to what is added to the average movie.