Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

AV1@Scale: Film Grain Synthesis, The Awakening

netflixtechblog.com

Post reply on HN
Print view View original

221–230 of 230 posts

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

#221

Post by strogonoff »

Thorrez wrote: post #150
majormajor wrote: post #147

Earlier quoted context omitted.

> So long as the synthesized noise doesn't have an obvious temporal pattern, comparing stills should be fine. The problem is that the initial noise-removal and compression passes still removed detail (that is more visible in motion than in stills) that you aren't adding back. If you do noise-removal well you don't have to lose detail over time. But it's much harder to do streaming-level video compression on a noisy s…

>The grain they're adding somewhat distracts from the compression blurriness but doesn't bring back the detail. Instead of wasting bits trying to compress noise, they can remove noise first, then compress, then add noise back. So now there aren't wasted bits compressing noise, and those bits can be used to compress detail instead of noise. So if you compare FGS compression vs non-FGS compression at the same bitrate,…

I imagined that at some point someone would come up with the idea “let’s remove more noise to compress things better and then add it back on the client”. Turns out, it is Netflix (I mean, who else wins so much from saving bandwidth).

Personally I rejected the idea after thinking about it for a couple of minutes, and I’m not yet sure I was wrong.

The challenge with noise is that it is actually cannot be perfectly automatically distinguished and removed from what could be finer details and textures even in a still photo, not to mention high-resolution footage. If removing noise was as simple as that, digital photography would be completely different. If you have removed noise, you can’t just add back missing detail later—if you could, you would not have removed it in the first place (alas, no algorithm is good enough, and even human eye can be faulty).

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

#222

Post by Thorrez »

strogonoff wrote: post #221
Thorrez wrote: post #150

Earlier quoted context omitted.

>The grain they're adding somewhat distracts from the compression blurriness but doesn't bring back the detail. Instead of wasting bits trying to compress noise, they can remove noise first, then compress, then add noise back. So now there aren't wasted bits compressing noise, and those bits can be used to compress detail instead of noise. So if you compare FGS compression vs non-FGS compression at the same bitrate,…

I imagined that at some point someone would come up with the idea “let’s remove more noise to compress things better and then add it back on the client”. Turns out, it is Netflix (I mean, who else wins so much from saving bandwidth). Personally I rejected the idea after thinking about it for a couple of minutes, and I’m not yet sure I was wrong. The challenge with noise is that it is actually cannot be perfectly auto…

I'm not saying that the final result is as good as the original.

I'm saying that the final result is better than standard compression at the same bitrate.

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

#223

Post by strogonoff »

Thorrez wrote: post #222
strogonoff wrote: post #221

Earlier quoted context omitted.

I imagined that at some point someone would come up with the idea “let’s remove more noise to compress things better and then add it back on the client”. Turns out, it is Netflix (I mean, who else wins so much from saving bandwidth). Personally I rejected the idea after thinking about it for a couple of minutes, and I’m not yet sure I was wrong. The challenge with noise is that it is actually cannot be perfectly auto…

I'm not saying that the final result is as good as the original. I'm saying that the final result is better than standard compression at the same bitrate.

That might be true; however, if this takes hold I would be surprised if they choose to keep producing and shipping the tasty grain high fidelity footage.

Considering that NR is generally among the very first steps in development pipeline (as that’s where it is the most effective), and the rest of dynamic range wrangling and colour grading comes on top of it, they might consider it a “waste” to 1) process two times (once with this new extreme NR, once with minimal NR that leaves the original grain), 2) keep around both copies, and especially (the costliest step) to 3) ship that delicious analog noise over Internet to people who want quality.

I mean, how far do we go? It’ll take even less bandwidth to just ship prompts to a client that generates the entire thing on the fly. Imagine the compression ratios…

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

#224

Post by account42 »

dylan604 wrote: post #197
account42 wrote: post #172

Earlier quoted context omitted.

What, cramped into a room with tons of other people who can't help themselves from making noise or moving in front of you while you only have limited and overpriced snack options. As nice as a big screen and professional sound equipment is the downsides make the experience strictly worse than a big OLED + half decent soundbar.

You must live alone. Even at home, you have people called family or friends that do not necessarily sit idle while watching TV. Watching with kids at home is worse than at the movies because they are at home and don't have the same social rules to follow. People at home are also not under the social rules of not using their devices, and second screening has become the norm. Yes, a theater probably holds more people t…

If your kids are badly behaved that's on you. If others are badly behaved in a semi-public setting there is not as much you can do about it.

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

#225

Post by sneak »

UltraSane wrote: post #219
sneak wrote: post #218

Earlier quoted context omitted.

Where did I refuse to watch anything? No amount of this attitude is going to make Casablanca or The Godfather or Pulp Fiction or Infinity War or Star Wars or Fight Club or 2001 or Top Gun be in any framerate other than 24fps. If they start making films in higher frame rates today, that won’t change that fact. Do you think people are going to stop watching films from the 50s, 60s, 70s, 80s, 90s, and 2000s? It would ta…

"no i will be watching 24fps films for the remainder of my life, which may be 40 more years. if all new films went up 1fps per year i would still go out to the movies in 20 years and be like “wtf is this crap?”" The Hobbit looked great at 48fps. Higher FPS failed only because reactionary people as yourself irrationally rejected it because "it looks weird!". You need to understand that 24fps is a compromise chosen to…

If you think the purpose of consuming film is to trigger rational responses in people, I don’t know what to tell you.

Do you do the same thing for poetry or food, too?

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

#226

Post by UltraSane »

sneak wrote: post #225
UltraSane wrote: post #219

Earlier quoted context omitted.

"no i will be watching 24fps films for the remainder of my life, which may be 40 more years. if all new films went up 1fps per year i would still go out to the movies in 20 years and be like “wtf is this crap?”" The Hobbit looked great at 48fps. Higher FPS failed only because reactionary people as yourself irrationally rejected it because "it looks weird!". You need to understand that 24fps is a compromise chosen to…

If you think the purpose of consuming film is to trigger rational responses in people, I don’t know what to tell you. Do you do the same thing for poetry or food, too?

Permanently rejecting faster frame rates for movies is like rejecting printed text in favor of handwritten manuscripts. You are rejecting a technological advance for extremely arbitrary reasons. If 23 or 25 or 30fps had become the standard you would be insisting that it was just as special.

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

#227

Post by sneak »

UltraSane wrote: post #226
sneak wrote: post #225

Earlier quoted context omitted.

If you think the purpose of consuming film is to trigger rational responses in people, I don’t know what to tell you. Do you do the same thing for poetry or food, too?

Permanently rejecting faster frame rates for movies is like rejecting printed text in favor of handwritten manuscripts. You are rejecting a technological advance for extremely arbitrary reasons. If 23 or 25 or 30fps had become the standard you would be insisting that it was just as special.

That’s correct - because then we’d have 100 years of movies embedded in our collective cultural shared experiences that are 25 or 30fps.

The point is the cultural significance, not the specific framerate. The chosen framerate is now significant because of the body of work that has been done in that format, and the inextricable experience of that framerate with that body of work.

It is anything but arbitrary! It’s a very real thing. The tyranny of the installed base is a well-documented phenomenon. In this case the installed base is the fond memories of a few billion people. Pretending that they are all irrational for not wanting higher framerates is plainly objectively incorrect, as a point of fact.

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

#228

Post by UltraSane »

sneak wrote: post #227
UltraSane wrote: post #226

Earlier quoted context omitted.

Permanently rejecting faster frame rates for movies is like rejecting printed text in favor of handwritten manuscripts. You are rejecting a technological advance for extremely arbitrary reasons. If 23 or 25 or 30fps had become the standard you would be insisting that it was just as special.

That’s correct - because then we’d have 100 years of movies embedded in our collective cultural shared experiences that are 25 or 30fps. The point is the cultural significance, not the specific framerate. The chosen framerate is now significant because of the body of work that has been done in that format, and the inextricable experience of that framerate with that body of work. It is anything but arbitrary! It’s a v…

So your basic thesis is that movies must always be 24fps because they have always been 24fps? Your mistaking familiarity with superiority.

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

#229

Post by Thorrez »

strogonoff wrote: post #223
Thorrez wrote: post #222

Earlier quoted context omitted.

I'm not saying that the final result is as good as the original. I'm saying that the final result is better than standard compression at the same bitrate.

That might be true; however, if this takes hold I would be surprised if they choose to keep producing and shipping the tasty grain high fidelity footage. Considering that NR is generally among the very first steps in development pipeline (as that’s where it is the most effective), and the rest of dynamic range wrangling and colour grading comes on top of it, they might consider it a “waste” to 1) process two times (o…

That argument could be made to reject any form of lossy compression.

Lossy compression enables many use cases that would otherwise be impossible. Is it annoying that streaming companies drive the bitrate overly low? Yes. However, we shouldn't blame the existence of lossy compression algorithms for that. Without lossy compression, streaming wouldn't be feasible in the first place.

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

#230

Post by maxglute »

kevinsync wrote: post #132

Ok, very cool. But I want Netflix to explain it related to Seinfeld, which at 10-12 feet looks fine, but up close looks insane. Blocky MJPEG + grain filter?? It's not like we're on Pentium II processors anymore -- I can filter just about anything with ShaderGlass [0] on a shitty computer (and some of the CRT shaders like crt-hyllian-curvature are brilliant, especially on old shows like NewsRadio that only exist on DV…

> Shaderglass + NewsRadio

I just want to say this is brilliant suggestion. Shit tier DVD rips of Newsradio really be elevated on shaderglass.

Post reply on HN