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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

#71

Post by bee_rider »

dylan604 wrote: post #57
rainworld wrote: post #22

Earlier quoted context omitted.

These days, when we see noise/grain in an end product it has likely been added in post-production. So, ideally, studios would provide distributors with a noiseless source plus grain synthesis parameters. Bonus: many viewers would welcome an option to turn it off.

> 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…

Netflix has their own in-house studio, right? The encoding and lossy compression is going to happen anyway. It seems like an easy win, for their directors to provide a description of the grain they want, so it can be replicated on the user side.

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

#73

Post by mmastrac »

dsjoerg wrote: post #72

[flagged]

There's no need for low-quality comments cutting and pasting from your favourite LLM. You can literally just type it into your browser's search bar and learn what it is, or spend a minute reading the wiki page (https://en.wikipedia.org/wiki/AV1).

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

#74

Post by rainworld »

dylan604 wrote: post #57
rainworld wrote: post #22

Earlier quoted context omitted.

These days, when we see noise/grain in an end product it has likely been added in post-production. So, ideally, studios would provide distributors with a noiseless source plus grain synthesis parameters. Bonus: many viewers would welcome an option to turn it off.

> 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…

And yet here we are: DNR -> fancy grain -> DNR -> basic, approximated grain. Because noise doesn’t compress. And you get compression artifacts even in Blu-ray releases. What’s the point of applying fancy grain when what a lot viewers end up seeing is an ugly smudge?

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

#75

Post by supertrope »

UltraSane wrote: post #52
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

Film grain and 24fps are both examples of people being far too attached to the technical limitations of film.

23.976 fps has been put on a pedestal as the "correct" look. Just look at the reaction to The Hobbit. However it does provide some objective advantages. 60 fps requires more lighting. Adding more lights means more electric setup and heat for actors in heavy makeup and costume. In post production that's more frames to edit.

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

#76

Post by Wowfunhappy »

dylan604 wrote: post #57
rainworld wrote: post #22

Earlier quoted context omitted.

These days, when we see noise/grain in an end product it has likely been added in post-production. So, ideally, studios would provide distributors with a noiseless source plus grain synthesis parameters. Bonus: many viewers would welcome an option to turn it off.

> 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'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 recognize that the locally-produced grain doesn't look quite right at the moment, but travel down the hypothetical with me for a moment. If you could make this work, why wouldn't you?

--------

...and yes, I acknowledge that once the grain is being added client side, the next logical step would be "well, we might as well let viewers turn it off." But, once we've established that client-side grain makes sense, what are you going to do about people having preferences? Should we outlaw de-noising video filters too?

I agree that the default setting should always match what the film maker intended—let's not end up with a TV motion smoothing situation, please for the love of god—but if someone actively decides "I want to watch this without the grain for my own viewing experience"... okay? You do you.

...and I will further acknowledge that I would in fact be that person! I hate grain. I modded Cuphead to remove the grain and I can't buy the Switch version because I know it will have grain. I respect the artistic decision but I don't like it and I'm not hurting anyone.

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

#77

Post by supertrope »

When you talk on a cellphone the codec AMR-WB nominally captures 50 Hz - 7000 Hz. However that's only on the optional highest bitrate 23.85 Kbps. The most common bitrate 12.65 Kbps only goes up to 6400 Hz and synthesizes 6400 - 7000 Hz from lower frequencies and noise as it sounds better than not having the noise!

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

#78

Post by dmbche »

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

It used to be a bigger deal (when digital cameras started being used) since people felt like digital video didn't look real/as good - movies shot on film were generally better looking (as crews were used shooting with it and digital video wasn't as sophisticated as today) and HAD grain.

It might be that there is a large part of the population that still has that association.

Cinephiles are also more likely to watch older (i.e. with grain) movies that ARE well shot and beautiful (which is why they are classics and watched by cinephiles) and not see bad film movies, only the cream of the crop, while being exposed to the whole gamut of quality when watching todays movies shot digitally. Would reinforce that grain = good while not being necessarily the case - and their opinion might be heard more than gen pop.

At any rate, it can be a neat tool to lower sharpness!

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

#79

Post by dylan604 »

rainworld wrote: post #74
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…

And yet here we are: DNR -> fancy grain -> DNR -> basic, approximated grain. Because noise doesn’t compress. And you get compression artifacts even in Blu-ray releases. What’s the point of applying fancy grain when what a lot viewers end up seeing is an ugly smudge?

The grain is there to hide the ugly smudge. that's the question they rather you didn't ask

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

#80

Post by aidenn0 »

fidotron wrote: post #3

There are definite philosophical questions over the merits of adding noise, but the problem with their example here is their denoising process appears to excessively blur everything, so both it and the synthesized grain image look noticeably less sharp than the source. The grain itself also looks too much like basic noise, and not really grain like.

AV1 has tunable FGS levels, and to my eye they went very slightly higher than they should have (though there are tradeoffs; at some bitrates the blurring+renoising is so much better than the other visual artifacts you will otherwise get, that you do want it that high).

A few things to note:

- still-frames are also a mediocre way to evaluate video quality.

- a theoretically perfect[1] noise-removal filter will always look less detailed than the original source, since your brain/eye system will invent more detail for a noisy image than for a blurry image.

1: By which I mean a filter that preserves 100% of the non-grain detail present, not one that magically recovers detail lost due to noise.

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