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There are definite philosophical questions over the merits of adding noise, but the problem with their example here is their denoising process appears to excess

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.

999900000999 1y ago
Since the beginning of film editors have added tricks in post. I would love for them to provide an option to view it with film simulation vs without. One of my favorite movies of all time, The Holdovers, did film simulation extremely well. It's set in the '70s so it attempts to look like a movie of that era. It looked great to me, but if you're an actual film nerd you're going to notice a lot of things aren't exactly accurate. Maybe in the near future we'll see Netflix being able to process some post effects on the client. So if you're color blind, you get a mode for that. If you don't want fake grain you can turn it off.
- ndriscoll 1y ago
  mpv can already do this: `--vf=format:film-grain=no` turns off grain synthesis. There are also people making custom shaders for things like emulating CRT monitors (originally for retro gaming, but I see there are also mpv versions).
- bee_rider 1y ago
  Holdovers was pretty great. Sorta like an 80’s school comedy but with the perspective of the adults included, making it a totally different type of movie.
rainworld 1y ago
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.
- NoMoreNicksLeft 1y ago
  I'll keep the film grain, I just want to be able to turn off laugh tracks.
  - account42 1y ago
    Why not just watch things where the creators don't feel they need to add laugh tracks in order to keep the audience engaged in the first place.
- dylan604 1y ago
  > 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 patterns that's been made available. 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
  - bee_rider 1y ago
    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.
    - dylan604 1y ago
      what does having an in-house studio have to do with it? they stream more content than just their own, and so they would not have creative license to alter content. they would only have some type of distribution license to stream the content as provided
dperfect 1y ago
> both it and the synthesized grain image look noticeably less sharp than the source That's true, but at a given bitrate (until you get to very high bitrates), the compressed original will usually look worse and less sharp because so many bits are spent trying to encode the original grain. As a result, that original grain tends to get "smeared" over larger areas, making it look muddy. You lose sharpness in areas of the actual scene because it's trying (and often failing) to encode sharp grains. Film Grain Synthesis makes sense for streaming where bandwidth is limited, but I'll agree that in the examples, the synthesized grain doesn't look very grain-like. And, depending on the amount and method of denoising, it can definitely blur details from the scene.
- bee_rider 1y ago
  It seems like a shame that they didn’t include a screenshot of the original (with natural grain), after suffering from low-bitrate streaming. Aka the actual baseline. I can see why they want to compare against the actual local copy of the video with the natural grain. But that’s the perfect copy that they can’t actually hope to match.
  - joemi 1y ago
    > It seems like a shame that they didn’t include a screenshot of the original (with natural grain), after suffering from low-bitrate streaming. Isn't that the image captioned "Regular AV1 (without FGS) @ 8274 kbps"?
    - bee_rider 1y ago
      I think I misread the figures. But still, they have: > A source video frame from They Cloned Tyrone > Regular AV1 (without FGS) @ 8274 kbps > AV1 with FGS @ 2804 kbps Just to emphasize the problem, would it be nice to see: Regular AV1 (without FGS) @ 2804 kbps It should look really bad, right? Which would emphasize their results.
      - joemi 1y ago
hypertexthero 1y ago
A film that explores this is Antonioni’s Blowup: https://en.wikipedia.org/wiki/Blowup https://en.wikipedia.org/wiki/Blowup
dylan604 1y ago
> and not really grain like that's an understatement. it just looks like RGB noise effect was added. film grain does not look like RGB noise. to me, film grain is only one part of what gave film the film look. the way the highlights bloom rather than clip. it also was more natural/organic/some descriptive other than the ultrasharp of modern digital acquisition. using some SoftFX or Black Mist type filters help, but it's just not the same as it is a digital vs analog type of acquisition. all of these attempts at making something look like it's not just keep falling down in the same ways. but hey, there's a cool tech blog about it this time. film grain filters have been around for a long time, yet people just don't care for them. even in Blu-ray time frame, there was attempts at removing the grain in the encode and applying it in playback. Netflix isn't coming up with anything new, and apparently nothing exciting either based on the results.
- kalleboo 1y ago
  I only have their single sample in the blog post to go by, but the original source frame also looks just like RGB noise? And the recreation looks really close if I swap between them. Looks fine to me. So as long they're analyzing the style of grain in the source properly, which the technical part of the post mentions they do...
- herf 1y ago
  Agree, I really prefer luminance noise when simulating film grain rather than treating RGB so independently - the RGB here looks wrong to me. If you are thinking about film, you wouldn't model it as pure photon/detector noise, because film has some crystalline structure and usually there is some correlation between the channels. (Some of the best grain is on B&W films though, which have wonderful structure and statistics.)
isx726552 1y ago
Agree, as someone who has spent way too much time studying the way motion picture film looks up close, this isn’t very realistic looking. It’s really just a form of dithering.
- ByThyGrace 1y ago
  Forget the film grain, give us film lint and film hair!
- ricardobeat 1y ago
  Video codecs use a lot of tricks based on human perception, perhaps it's much closer to the real thing when in motion vs a still image?
aidenn0 1y ago
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.
p1necone 1y ago
Get the retro gaming nerds on this, they'll make a film grain shader that's indistinguishable from reality in no time flat.

999900000999 1y ago

Since the beginning of film editors have added tricks in post. I would love for them to provide an option to view it with film simulation vs without. One of my favorite movies of all time, The Holdovers, did film simulation extremely well. It's set in the '70s so it attempts to look like a movie of that era. It looked great to me, but if you're an actual film nerd you're going to notice a lot of things aren't exactly accurate. Maybe in the near future we'll see Netflix being able to process some post effects on the client. So if you're color blind, you get a mode for that. If you don't want fake grain you can turn it off.

ndriscoll 1y ago
mpv can already do this: `--vf=format:film-grain=no` turns off grain synthesis. There are also people making custom shaders for things like emulating CRT monitors (originally for retro gaming, but I see there are also mpv versions).
bee_rider 1y ago
Holdovers was pretty great. Sorta like an 80’s school comedy but with the perspective of the adults included, making it a totally different type of movie.

rainworld 1y ago

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.

NoMoreNicksLeft 1y ago
I'll keep the film grain, I just want to be able to turn off laugh tracks.
- account42 1y ago
  Why not just watch things where the creators don't feel they need to add laugh tracks in order to keep the audience engaged in the first place.
dylan604 1y ago
> 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 patterns that's been made available. 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
- bee_rider 1y ago
  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.
  - dylan604 1y ago
    what does having an in-house studio have to do with it? they stream more content than just their own, and so they would not have creative license to alter content. they would only have some type of distribution license to stream the content as provided

dperfect 1y ago

> both it and the synthesized grain image look noticeably less sharp than the source That's true, but at a given bitrate (until you get to very high bitrates), the compressed original will usually look worse and less sharp because so many bits are spent trying to encode the original grain. As a result, that original grain tends to get "smeared" over larger areas, making it look muddy. You lose sharpness in areas of the actual scene because it's trying (and often failing) to encode sharp grains. Film Grain Synthesis makes sense for streaming where bandwidth is limited, but I'll agree that in the examples, the synthesized grain doesn't look very grain-like. And, depending on the amount and method of denoising, it can definitely blur details from the scene.

bee_rider 1y ago
It seems like a shame that they didn’t include a screenshot of the original (with natural grain), after suffering from low-bitrate streaming. Aka the actual baseline. I can see why they want to compare against the actual local copy of the video with the natural grain. But that’s the perfect copy that they can’t actually hope to match.
- joemi 1y ago
  > It seems like a shame that they didn’t include a screenshot of the original (with natural grain), after suffering from low-bitrate streaming. Isn't that the image captioned "Regular AV1 (without FGS) @ 8274 kbps"?
  - bee_rider 1y ago
    I think I misread the figures. But still, they have: > A source video frame from They Cloned Tyrone > Regular AV1 (without FGS) @ 8274 kbps > AV1 with FGS @ 2804 kbps Just to emphasize the problem, would it be nice to see: Regular AV1 (without FGS) @ 2804 kbps It should look really bad, right? Which would emphasize their results.
    - joemi 1y ago

hypertexthero 1y ago

A film that explores this is Antonioni’s Blowup: https://en.wikipedia.org/wiki/Blowup https://en.wikipedia.org/wiki/Blowup

dylan604 1y ago

> and not really grain like that's an understatement. it just looks like RGB noise effect was added. film grain does not look like RGB noise. to me, film grain is only one part of what gave film the film look. the way the highlights bloom rather than clip. it also was more natural/organic/some descriptive other than the ultrasharp of modern digital acquisition. using some SoftFX or Black Mist type filters help, but it's just not the same as it is a digital vs analog type of acquisition. all of these attempts at making something look like it's not just keep falling down in the same ways. but hey, there's a cool tech blog about it this time. film grain filters have been around for a long time, yet people just don't care for them. even in Blu-ray time frame, there was attempts at removing the grain in the encode and applying it in playback. Netflix isn't coming up with anything new, and apparently nothing exciting either based on the results.

kalleboo 1y ago
I only have their single sample in the blog post to go by, but the original source frame also looks just like RGB noise? And the recreation looks really close if I swap between them. Looks fine to me. So as long they're analyzing the style of grain in the source properly, which the technical part of the post mentions they do...
herf 1y ago
Agree, I really prefer luminance noise when simulating film grain rather than treating RGB so independently - the RGB here looks wrong to me. If you are thinking about film, you wouldn't model it as pure photon/detector noise, because film has some crystalline structure and usually there is some correlation between the channels. (Some of the best grain is on B&W films though, which have wonderful structure and statistics.)

isx726552 1y ago

Agree, as someone who has spent way too much time studying the way motion picture film looks up close, this isn’t very realistic looking. It’s really just a form of dithering.

ByThyGrace 1y ago
Forget the film grain, give us film lint and film hair!
ricardobeat 1y ago
Video codecs use a lot of tricks based on human perception, perhaps it's much closer to the real thing when in motion vs a still image?

aidenn0 1y ago

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.

p1necone 1y ago

Get the retro gaming nerds on this, they'll make a film grain shader that's indistinguishable from reality in no time flat.