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AV1@Scale: Film Grain Synthesis, The Awakening

netflixtechblog.com

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Re: AV1@Scale: Film Grain Synthesis, The Awakening

#101

Post by Wowfunhappy »

crazygringo wrote: post #97
jedbrooke wrote: post #2

> This grain, formed from tiny particles during the film’s development, is more than just a visual effect. It plays a key role in storytelling by enhancing the film’s depth and contributing to its realism. I never understood the “grain = realism” thing. my real eyes don’t have grain. I do appreciate the role of grain as an artistic tool though, so this is still cool tech

> my real eyes don’t have grain. They definitely do at night when it's dark out. There's a kind of "sparkling" or "static" that comes in faint light. Fortunately, our eyes have way better sensitivity than cameras. But the "realism" just comes from how it was captured using the technology of the day. It's no different from phonograph hiss or the way a CRT signal blurs. The idea is to be "real" to the technology that t…

Your Van Gogh analogy makes sense for old movies. It doesn't quite explain why we're still adding grain to new movies, except for those few which are purposefully evoking older movies.

Re: AV1@Scale: Film Grain Synthesis, The Awakening

#102

Post by dylan604 »

Wowfunhappy wrote: post #76
dylan604 wrote: post #57

Earlier quoted context omitted.

> provide distributors with a noiseless source plus grain synthesis parameters. What parameters would that be? Make it look like Eastman Ektachrome High-Speed Daylight Film 7251 400D? For years, people have taken film negative onto telecines and created content of grain to be used as overlays. For years, colorists have come up with ways of simulating the color of specific film stocks by using reference film with test…

> If a director/producer wants film grain added to their digital content, that's where it should be done in post. Not by some devs working for a streaming platform. The use of grain or not is a creative decision made by the creators of the work. That's where it should remain Why? If you're spending a significant chunk of your bits just transmitting data that could be effectively recreated on the client for free, isn'…

> Why? If you're spending a significant chunk of your bits just transmitting data that could be effectively recreated on the client for free, isn't that wasteful? Sure, maybe the grains wouldn't be at the exact same coordinates, but it's not like the director purposefully placed each grain in the first place.

I'm sorry your tech isn't good enough to recreate the original. That does not mean you get to change the original because your tech isn't up to the task. Update your task to better handle the original. That's like saying an image of the Starry Night doesn't retain the details, so we're going to smear the original to fit the tech better. No. Go fix the tech. And no, this is not fixing the tech. It is a band-aid to cover the flaws in the tech.

Re: AV1@Scale: Film Grain Synthesis, The Awakening

#103

Post by dylan604 »

dperfect wrote: post #67
dylan604 wrote: post #58

Earlier quoted context omitted.

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 den…

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.

Re: AV1@Scale: Film Grain Synthesis, The Awakening

#104

Post by dylan604 »

Wowfunhappy wrote: post #100
kridsdale1 wrote: post #83

Earlier quoted context omitted.

Because it looks amazing in the editing studio. Just like the sound mix is incredible on the Atmos monitors in the sound mixing room, even though the home viewers have a soundbar at best and tiny stereo speakers in a flat panel typically. The dynamics and dialog channel will be fucked. But that’s user error.

This is exactly why theatrical releases are so important to movie producers, isn't it?

Theatrical release qualifies for certain awards and shiny statues. That's their concern. If a streaming platform wants to give them enough cash to beat out projected box office earnings, then they'll take it if they don't have any grandiose visions of golden statues.

Re: AV1@Scale: Film Grain Synthesis, The Awakening

#106

Post by Wowfunhappy »

dylan604 wrote: post #102
Wowfunhappy wrote: post #76

Earlier quoted context omitted.

> If a director/producer wants film grain added to their digital content, that's where it should be done in post. Not by some devs working for a streaming platform. The use of grain or not is a creative decision made by the creators of the work. That's where it should remain Why? If you're spending a significant chunk of your bits just transmitting data that could be effectively recreated on the client for free, isn'…

> Why? If you're spending a significant chunk of your bits just transmitting data that could be effectively recreated on the client for free, isn't that wasteful? Sure, maybe the grains wouldn't be at the exact same coordinates, but it's not like the director purposefully placed each grain in the first place. I'm sorry your tech isn't good enough to recreate the original. That does not mean you get to change the orig…

Because the specks of grain aren't at the exact same coordinates? What differences are we talking about here exactly?

Re: AV1@Scale: Film Grain Synthesis, The Awakening

#107

Post by kderbe »

crazygringo wrote: post #96

This fails to acknowledge that synthesized noise can lack the detail and information in the original noise . When you watch a high-quality encode that includes the actual noise, there is a startling increase in resolution from seeing a still to seeing the video. The noise is effectively dancing over a signal, and at 24 fps the signal is still perfectly clear behind it. Whereas if you lossily encode a still that disca…

Grain is independent frame-to-frame. It doesn't move with the objects in the scene (unless the video's already been encoded strangely). So long as the synthesized noise doesn't have an obvious temporal pattern, comparing stills should be fine.

Regarding aesthetics, I don't think AV1 synthesized grain takes into account the size of the grains in the source video, so chunky grain from an old film source, with its big silver halide crystals, will appear as fine grain in the synthesis, which looks wrong (this might be mitigated by a good film denoiser). It also doesn't model film's separate color components properly, but supposedly that doesn't matter because Netflix's video sources are often chroma subsampled to begin with: https://norkin.org/pdf/DCC_2018_AV1_film_grain.pdf

Disclaimer: I just read about this stuff casually so I could be wrong.

Re: AV1@Scale: Film Grain Synthesis, The Awakening

#108

Post by dylan604 »

Wowfunhappy wrote: post #106
dylan604 wrote: post #102

Earlier quoted context omitted.

> Why? If you're spending a significant chunk of your bits just transmitting data that could be effectively recreated on the client for free, isn't that wasteful? Sure, maybe the grains wouldn't be at the exact same coordinates, but it's not like the director purposefully placed each grain in the first place. I'm sorry your tech isn't good enough to recreate the original. That does not mean you get to change the orig…

Because the specks of grain aren't at the exact same coordinates? What differences are we talking about here exactly?

The differences are actual film grain vs some atrocious RGB noise artificially added by the streamer. How is that unclear? What else could we be talking about?

Re: AV1@Scale: Film Grain Synthesis, The Awakening

#109

Post by Wowfunhappy »

dylan604 wrote: post #108
Wowfunhappy wrote: post #106

Earlier quoted context omitted.

Because the specks of grain aren't at the exact same coordinates? What differences are we talking about here exactly?

The differences are actual film grain vs some atrocious RGB noise artificially added by the streamer. How is that unclear? What else could we be talking about?

Right, the current implementation is bad.

In theory though, I don't see any reason why client-side grain that looks identical to the real thing shouldn't be achievable, with massive bandwidth savings in the process.

It won't be, like, pixel-for-pixel identical, but that was why I said no director is placing individual grain specks anyway.

Re: AV1@Scale: Film Grain Synthesis, The Awakening

#110

Post by Animats »

Film grain needs to die. Its time is past. Sepia photographs and running 16 FPS silent film at 24 FPS are already dead. Next, film grain.

Eastman Business Park in Rochester has been demolished.

Also, please stop putting dust and scratches on YouTube videos. Thank you.

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