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AV1@Scale: Film Grain Synthesis, The Awakening
- jedbrooke 1y ago> 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
- jccalhoun 1y agofilm grain adds realism in the same way that high frame rate films look wrong or vinyl sounds "warmer" or tube guitar amps sound "better" - It is what we are used to.
- bob1029 1y agoFilm grain can create stochastic resonance with the underlying ground truth. In practice, this can improve the perceived image quality over having none.
- tiluha 1y agoMine do, at least when it's very dark
- 01HNNWZ0MV43FF 1y agoYeah I've had visual snow, I think only when I'm tired, stood up too fast, dehydrated, etc. https://en.wikipedia.org/wiki/Visual_snow_syndrome https://en.wikipedia.org/wiki/Visual_snow_syndrome
- account42 1y agoIt's not even that, just under low light conditions (after you let your eyes adjust to see anything at all) everyone will see quite a bit of noise.
- GuB-42 1y agoThe way I see it is that grain makes the film look more detailed than it really is, it can also hide compression artefacts and blurriness. I don't know the psychovisuals behind that. Maybe it adds some high frequencies that compression often washes out, or maybe acts like some kind of dithering. As for your eyes, I am pretty sure that they have grain, that's how quantum physics work, you just don't perceive it because your brain filters it out. But again, I don't know how it interacts with film grain.
- plastic3169 1y agoVideo signal without the noise or grain is annoying to watch as it makes everything in the ”out of focus” zone look smooth blurry. Your eyes want to focus yet it is an illusion of depth without an actual depth. Noise texture emphasizes that this is just a 2D plane after all so your eyes can rest and the viewer doesn’t feel like they need glasses. This is just my theory of it based on observation. No research behind it.
- dinfinity 1y ago> As for your eyes, I am pretty sure that they have grain And lots of it, actually. Just close your eyes or look at any non-textured surface. Tons of noise. The decreasing signal-to-noise ratio is also highly noticeable when it gets darker.
- observationist 1y agoPeople are always trying to rationalize and justify aesthetic preferences. The depth and nuance of your understanding of a thing will change how you perceive variations of that thing, whether it's guitar tonewoods, style of music, types of paint, flavor of beer, or the grain in film. If you know a lot about a subject, you can tell a lot about the history of a thing, and that's going to change how you feel about a thing. A child watching a Buster Keaton skit and gasping and giggling and enjoying it is going to have a different subjective aesthetic experience of the media than a film critic who knows exactly what type of film and camera were used, and what the meaning of all the different abstractions imply about the scene, and the fabric of Keaton's costume, and so on, and so forth. Subjective aesthetic preferences are in the realm of cognition - we need a formal theory of intelligence mapped to the human brain, and all of these subjective phenomena collapse into individualized data processing and initial conditions. There's something about film grain contrasted against clean cel animation which might make it easier for people to suspend disbelief. They are conditioned to think that absence of grain is associated with unreal animation, particular types of media, and CGI. Home video and news and so forth had grain and low quality, so grain gets correlated with "real". In my view, there's nothing deeper than that - we're the product of our times. In 40 years, media will have changed, and it may be that film grain is associated with surrealism, or edited out completely, as it's fundamentally noise.
- Kina 1y agoThis reminds me of modern windows having fake panes. They’re just strips that are applied to give the impressions that there are multiple smaller panes because people are used to that and it feels “correct”. I have to imagine past glassmakers would have been absolutely enthralled by the ability we now have to make uniform, large sheets of glass, but here we are emulating the compromises they had to make because we are used to how it looks.
- throw0101d 1y ago> They’re just strips that are applied to give the impressions that there are multiple smaller panes because people are used to that and it feels “correct”. It is more than just 'feeling correct': windows and their various (sub-)elements that make them up (can) change the architectural proportions and how the building is perceived as a whole: * https://www.youtube.com/watch?v=uAMyUoDz4Og https://www.youtube.com/watch?v=uAMyUoDz4Og * https://www.youtube.com/watch?v=_c8Ahs9Tcnc&t=49 https://www.youtube.com/watch?v=_c8Ahs9Tcnc&t=49 It is similar with columns: they're not just 'tall-and-narrow', but rather have certain proportions and shapes depending on the style and aesthetic/feeling one wishes to convey: * https://en.wikipedia.org/wiki/Classical_order https://en.wikipedia.org/wiki/Classical_order And these proportions can even be 'fractal': the window panes related to windows as a whole, related to the building as a whole: * https://www.youtube.com/watch?v=J-0XJpPnlrA&t=3m13s https://www.youtube.com/watch?v=J-0XJpPnlrA&t=3m13s * https://en.wikipedia.org/wiki/Golden_rectangle https://en.wikipedia.org/wiki/Golden_rectangle * https://en.wikipedia.org/wiki/List_of_works_designed_with_the_golden_ratio https://en.wikipedia.org/wiki/List_of_works_designed_with_th... * https://www.nngroup.com/articles/golden-ratio-ui-design/ https://www.nngroup.com/articles/golden-ratio-ui-design/
- UltraSane 1y agoI strongly doubt that multiple smaller panes would have ever become a common style if we could have always made large glass panes. This is a perfect example of people becoming very used to a style forced by a technological limitation that is emulated even after the limitation doesn't exist.
- haiku2077 1y agoMy vision is grainy because of visual snow. Which is why I turn off film grain in games, it stacks on my vision and makes a visual mess.
- recursive 1y agoIf your eyes did have grain, then it would still be applied to watching an "ungrained" film, as you're still using the same eyes.
- sneak 1y agograin and 24fps and widescreen trigger certain contextual emotions around the movie-watching experience. remove them and your brain contextualizes the video very differently. this is likely the result of ~100 years of film-based filmmaking and projection. hell, we still call it filmmaking.
- UltraSane 1y agoYes, it is only the result of familiarity. We could gradually increase the frame rate of movies made in a year by 1 fps per year and then no one would even notice after 24 years every new movie would be 48fps.
- sneak 1y agoNo, it would take a lot longer than that. You’re fighting 100 years of tradition.
- UltraSane 1y agoYou would notice 1 fps more per year?
- sneak 1y agono 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?” it would take a generation or more to eradicate this cultural context. casablanca is never going to be in 48fps.
- kderbe 1y agoThe article points out the masking effect of grain, which hides the fake-looking compression artifacts, and also the familiarity/nostalgia aspect. But I will offer an additional explanation. Look around you: nearly all surfaces have some kind of fine texture and are not visually uniform. When this is recorded as video, the fine texture is diminished due to things like camera optics, limited resolution, and compression smoothing. Film grain supplies some of the high frequency visual stimulus that was lost. Our eyes and brains like that high frequency stimulation and aren't choosy about whether the exact noise pattern from the original scene is reproduced. That's why the x265 video encoder (which doesn't have grain synthesis since it produces H.265 video) has a psy-rd parameter that basically says, "try to keep the compressed video as 'energetic' as the original, even if the energy isn't in the exact same spot", and even a psy-rdoq parameter that says, "prefer higher 'energy' in general". These parameters can be adjusted to make a compressed video look better without needing to store more data.
- UltraSane 1y agoFilm grain and 24fps are both examples of people being far too attached to the technical limitations of film.
- supertrope 1y ago23.976 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.
- UltraSane 1y agoIsn't it strange how people accepted much bigger changes like sound and color but are now balking at higher frame rates?
- LocalH 1y ago23.976fps is only "correct" when telecining to a 59.94Hz format. 24fps round is the "correct" format in terms of actual filmmaking. I don't know of many films specifically shot at 23.976fps.
- fc417fc802 1y ago> 60 fps requires more lighting. Assuming the comparison uses the same image sensor for each.
- smusamashah 1y agoGrain = realism because real captured grain isn't total random noise. It's authentic noisy data. It's part of captured scene. It adds subtle tiny but real detail to the scene. Unless I am corrected here and that real grain is also total random noise.
- dmbche 1y agoIt 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!
- tshaddox 1y agoIt's doubling back on itself. The film grain makes the footage look "cinematic" because it's how old movies looked.
- crazygringo 1y ago> 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 the filmmaker used, and the way they knew their movie would be seen. It's the same way Van Gogh's brush strokes were real to his paintings. You wouldn't want his oil paintings sanded down to become flat. It's the reality of the original medium. And so even when we have a digital print of the film, we want to retain as much of the reality of the original as we can.
- Wowfunhappy 1y agoYour 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.
- crazygringo 1y agoWe don't use obvious grain, usually. That's generally precisely to evoke something about the past -- for flashbacks, a period look, etc. A sense of grittiness like 70s movies, etc. On the other hand, a small amount of constant grain or noise is intentionally often introduced because otherwise images feel too static and end up looking almost fake. Similarly, dithering is intentionally added to audio, like mastering CD's or tracks. It helps prevent artifacts in video and in audio.
- kuschku 1y agoEven modern cameras have grain. If you need to integrate your scene with motion graphics, background replacement, or vfx, you'll need to remove grain on part of the image, edit it, add the original grain back where possible and synthesize new grain elsewhere. Often it can also make sense to modify the grain for aesthetics. Denoising usually produces a less detailed result, but what you can do is denoise only the color channels, not the brightness channel. Brightness noise looks normal to us, while color noise tends to look very artificial. But by keeping the brightness noise, you avoid losing detail to the denoiser.
- deleted 1y ago[deleted]
- account42 1y agoYour eyes have lots of grain in low light conditions.
- FireInsight 1y agoIt's funny, because I've always had a subtle visual snow that looks like a film grain on top of everything I see, and for a long time I thought everybody had it and that that's why artificial grain is added, to make pictures appear more realistic. I've since learned that not everybody sees the world like I do, but I still do love to see grain and noise in pictures. Only RGB noise I often find dreadfully ugly when looked at up close, which is a shame, since that is exactly what most color cameras include.
- barbazoo 1y agoHonestly to me it reads like a solution looking for a problem. I’ve never considered non deterministic imperfections that happen during recording of the movie to be essential to storytelling.
- afiori 1y agoGrain in movies has a similar role to grain in leather products, it is an indicator of authenticity
- fidotron 1y agoThere 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 agoSince 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 agompv 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 agoHoldovers 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 agoThese 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.
- jrm4 1y agoYup, yet another example of the thing I'll never stop finding fascinating: ANY noticeable percieved "flaw" in any creative media will eventually become an aesthetic choice.
- 0cf8612b2e1e 1y agoFor an example, watch Shogun. Director apparently thought that most of the screen being out of focus was a positive. Quite distracting.
- UltraSane 1y agoOr Snyder's terrible zombie movie Army of the Dead where he uses lenses with very shallow depth of field that makes almost everything look out of focus. It is very annoying.
- jccalhoun 1y agoI've noticed this in a few things the last few years. The top and bottom of the shot are out of focus and it is super distracting to me. Maybe it is meant to draw the eye to the middle of the frame.
- Mashimo 1y agoYup, notice that as well. A blurry vignette. Needle sharp in the center, but objects that are the same distance are blurry at the edges of the frame. At first I thought they use vintage lenses, but it's probably done in post. I sometimes do something similar on photos, where I darken the edges a bit.
- account42 1y ago> I sometimes do something similar on photos, where I darken the edges a bit. Which is also an emulation of the shortcomings of older/worse technology.
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- vachina 1y agoWhen you ran out of things to innovate on.
- derf_ 1y agoThe "at scale" part is the real story here. Film Grain Synthesis has been available in the usual AV1 encoders for a while, but required some amount of manual tweaking to avoid creating problems, meaning it was only used in production when you had a very limited catalog, or for particularly important titles. They do not provide a lot of details here about how they overcame those problems, but it is nice to see it being deployed more broadly.
- tvshtr 1y agoThere's adaptive variant nowadays which makes things much easier to automate.
- brcmthrowaway 1y agoThey should use FPGA acceleration for this.
- shashanoid 1y agoI love grain! 16mm vibes
- sharpshadow 1y agoFake grain really disgusts me.
- ricardobeat 1y agoThis is not fake grain - it's a reproduction of the original grain pattern, compressed separately from the underlying image content. The result is closer to the original picture than the denoised / compressed version.
- fc417fc802 1y agoDepends on your definition of fake. I consider this to have crossed the line from lossy compression to a generative product.
- sharpshadow 1y agoIf I understood it correctly they take one sample of grain and do random smaller samples of it to fill the picture with. That’s not even the original grain from each frame, but one sample for the whole video. The technique is awesome, saves huge amount of bandwidth. Personally I just like the original grain from each frame much much more, from an artistic standpoint.
- ChrisArchitect 1y agoHow much grain is there in IMAX films? There's an influx of high-profile directors/films right now and in pipeline filmed for IMAX (F1: The Movie I think, Mission Impossible, etc) and Christopher Nolan's Odyssey coming next year shot entirely on IMAX film with newly developed smaller/quieter cameras made to accomplish it.
- CharlesW 1y ago> How much grain is there in IMAX films? I've read that a 15-perf 65mm IMAX negative shot with slower film stocks is "virtually grainless", even when viewed on a 70ft screen. Grain is apparently noticeable in IMAX films when large/fast stocks are used and pushed toward their limits, and (of course) when smaller-format film stocks have been blown up.
- eviks 1y ago> Picture this: you’re watching a classic film, and the subtle dance of film grain adds a layer of authenticity and nostalgia to every scene It just adds visual noise that obscures details of the authentic scene, and nothing prevents nostalgia from being tied to many of the more prominent visual cues like old actors or your own old memories from when you watched it first... > contributing to [film's] realism But there is no grain in reality, so it does the opposite Otherwise I'm glad AV1 marches along and instead of wasting bitrate encoding visual garbage has an algorithmic replacement mechanism- which also means you could turn it off easier.
- messe 1y ago> It just adds visual noise that obscures details of the authentic scene Does it add any more than modern video compression techniques? What constitutes noise in cinema, is somewhat subjective.
- eviks 1y agoWhich modern compression artifacts that are still visible at high bitrates do you have in mind that would similarly detail-obscuring?
- meatmanek 1y ago> But there is no grain in reality, so it does the opposite Well ackchually -- illumination is inherently random, so all time-bounded captures of a scene (including what your eyes do) are subject to shot noise: https://en.wikipedia.org/wiki/Shot_noise https://en.wikipedia.org/wiki/Shot_noise
- eviks 1y agoYou misackchuallied grain with any noise, for example, the bottom right square of the image at the wiki page is not grainy despite being technically shot-noisy
- kibwen 1y agoDocumentaries might care about accurately representing reality. For every other cinematic genre, "authenticity" is not an inherent goal. If film grain is part of the director's vision, then that's just as valid as a choice to have dramatic non-diagetic music playing in the background of a scene (which is highly inauthentic, but also highly effective at evoking emotion, which is the point of art).
- kelsey98765431 1y agohappier and happier about leaving behind digital media to return to physical. to me this is literally slop. i want the uncompressed file stop selling me stepped on product
- ConanRus 1y agoagree
- aidenn0 1y agoYour statement makes me think that one of the following is true: 1. You prefer Betamax or VHS to digital media (highly unlikely) 2. You own laserdiscs (limited to 480i) 3. You own 35mm prints of film. Since all other formats film has been made available on are both digital media and compressed.
- account42 1y ago> 2. You own laserdiscs (limited to 480i) Down-scaling to 480i is also a form of compression so you can discount that one.
- recursive 1y agoUncompressed 4k video is ~5Gbps (3840 * 2160 * 3 * 24 * 8). A 2-hour movie clocks in at about 4.3TB. (3840 * 2160 * 3 * 24 * 60 * 60 * 2) All that is 24fps. That's without audio, which I assume you also want to be uncompressed.
- fc417fc802 1y agoTBF even as bloated as 48/24 FLAC is it's a rounding error at that point.
- recursive 1y agoBut FLAC is compressed. Don't forget 13 channels. Only the best! Probably 192 khz.
- 0556834414 1y ago[flagged]
- ConanRus 1y agoEverything is fake now. I want a technology which works with a raw film scans, not even compressing them to JPEG, which is a 1st step in loosing the details BTW. Motion detection, key frames, delta frames - fine. But with a lossless video. On a Blu Ray off course, i don't care much about streaming.
- zerocrates 1y agoI wonder how much you'd get with such a technology... truly uncompressed 4K video you're talking about something on the order of a few terabytes for a 90-minute movie, so way way bigger than the biggest 4K Blu-ray discs. Lossless compression would get you under that number, but far enough to matter?
- CharlesW 1y agoA 4K/24p film encoded with Apple ProRes 4444 XQ (not even ProRes RAW) is 716 GB per hour, so you would need to swap a total of 30 Blu-ray discs once every 4 minutes in order to watch a 2 hour movie.
- account42 1y agoUHD discs used for 4K movies today already store much more than 24 GB per disc.
- _bent 1y agoIt's a bit frustrating that the footage is first shot, then denoised in post, then renoised in post, then denoised in encoding and then renoised at decoding.
- sneak 1y agoOnly if you are aware of it, which 99.9% of people consuming video content are not. It’s simply an unimportant implementation detail (from a viewer’s perspective who doesn’t really care about bitrate-as-cost).
- dist-epoch 1y agoYou worry too much, it's all fake. What you think is the "footage" will be many layers from various sources composited together. Fake lights, fake shadows, fake sky, ...
- UltraSane 1y agoBetween 24fps and film grain people are way too attached to fundamentally inferior technology. With how strongly people resist frame rates faster than 24 I'm surprised people accepted color and sound, which were much bigger changes.
- vessenes 1y agoI like this. Not really because I feel modern media should have added grain, but because for older media this is a method to get closer to the original but at much lower bitrates without excessive smoothing. What’s not to like? Also, the author had me at God of Gamblers 2. So good. I will take him up on his recommendation to rewatch.
- dperfect 1y agoTo 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.
- dylan604 1y agoMy 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
- dperfect 1y agoI 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!
- dylan604 1y agoFor 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.
- smusamashah 1y agoThe original grain that is captured is actually a detail and not total random noise. I believe you can make up the vague sense of original scene if you could somehow extract that grain/noise alone. It's like reducing an image to tiny dots with dithering (reminds of Atinkson dithering). Those grains are not a noise, they are a detail, actual data. That's why real grain looks good IMO.
- mmastrac 1y agoIf you extract the grain (e.g. by subtracting a blurred version of the image), the result contains mostly noise, not meaningful scene information outside of some variation according to image brightness. Film grain is random, so the extracted "grain layer" doesn’t encode original image detail but film grain itself encodes relative lightness in its _density_.
- account42 1y agoMostly noise but not just noise. There is a reason why quality de-noising is a hard problem and the lost information becomes more apparent for videos where our brain is better able to extract it from the original noise.
- dan-robertson 1y agoThis is just a fact of lossy compression: you want to throw away information that contributes less to the perception of the video so that you can describe it with fewer bits of information. There are two possible advantages for this kind of grain synthesis. For Netflix, they could produce the same perceived quality at lower bitrates, which reduces costs per view and allows customers with marginally slow connections to get a higher quality version. For a consumer, the advantage would be getting more non-grain detail for a fixed bitrate. You are right that if you subtract the dentists frame from the raw one, showing only the estimated noise, you would get some impression of the scene. I think there’s two reasons for this. Firstly, the places where the denoiser produced a blurry line that should be sharp may show up as faint lines. I don’t think this is ‘hidden information’ so much as it is information lost to lossy compression. In the same way, if you look at the difference between a raw image and one with compression, you may see some emphasized edges due to compression artefacts. Secondly, the less exposed regions of the film will have more noise so noisiness becomes a proxy for darkness, allowing some reproduction of the scene. I would expect this detail to be lost after adjusting for the piecewise linear function for grain intensity at different brightness levels. Perhaps a third thing is the level of noise in the blacks and the ‘grain size’ or other statistical properties tell you about the kind of film being used, but I think those things are captured in the film grain simulation model. Possibly there are some other artefacts like evidence of special effects, post processing, etc.
- periodjet 1y ago"Your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should."
- dsjoerg 1y ago[flagged]
- mmastrac 1y agoThere'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 https://en.wikipedia.org/wiki/AV1).
- dsjoerg 1y agoI disagree. I wish that when obscure terms were used, there would be an explanation of that specific term either in the article itself or, failing that, in an HN comment. This is especially helpful because sometimes a term will have multiple meanings in different verticals, which then requires each reader to not only search for the term but work out which context it's all about. Rather than each reader do that work, why not attach a good & appropriate explanation closer to the article itself? That's what I was attempting to do.
- supertrope 1y agoWhen 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!
- lampiaio 1y agoThis sent me down a very interesting rabbit hole, thanks!
- dudeinjapan 1y agoPlease also add more noise to the audio track.
- crazygringo 1y agoThis 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 discards the noise and then adds back artificial noise to match the original "aesthetically", the original detail is non-recoverable if this is done frame-by-frame. Watching at 24 fps produces a fundamentally blurrier viewing experience. And it's not subtle -- on old noisy movies the difference in detail can be 2x. Now, if h.265 or AV1 is actually building its "noise-removed" frames by always taking into account several preceding and following frames while accounting for movement, it could in theory discover the signal of the full detail across time and encode that, and there wouldn't be any loss in detail. But I don't think it does? I'd love to know if I'm mistaken. But basically, the point is: comparing noise removal and synthesis can't be done using still images. You have to see an actual video comparison side-by-side to determine if detail is being thrown away or preserved. Noise isn't just noise -- noise is detail too.
- kderbe 1y agoGrain 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 https://norkin.org/pdf/DCC_2018_AV1_film_grain.pdf Disclaimer: I just read about this stuff casually so I could be wrong.
- alright2565 1y agoI think you've missed the point here: the noise in the originals acts as dithering, and increases the resolution of the original video. This is similar to the noise introduced intentionally in astronomy[1] and in signal processing[2]. Smoothing the noise out doesn't make use of that additional resolution, unless the smoothing happens over the time axis as well. Perfectly replicating the noise doesn't help in this situation. [1]: https://telescope.live/blog/improve-image-quality-dithering https://telescope.live/blog/improve-image-quality-dithering [2] https://electronics.stackexchange.com/questions/69748/using-noise-to-increase-effective-resolution-of-adc https://electronics.stackexchange.com/questions/69748/using-...
- lossolo 1y agoWhen I watch an 80 GB 4K movie from Blu-ray, the last thing I want is film grain, which makes it look like a VHS recording from the 90s.
- account42 1y agoFilm grain (real or artificial) is nothing like VHS artifacts.
- lossolo 1y agoIt was an analogy. What I meant is that when I'm watching something in super high quality like a 4K Blu-ray, the presence of heavy film grain feels like a step backward visually, kind of like how VHS looked compared to today's standards. It takes away from the clean, sharp image I expect from that format.
- Animats 1y agoFilm 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.
- jebarker 1y agoFake film grain maybe, but saying all film grain needs to die is like saying oil painting brush strokes need to die.
- Mashimo 1y agoBut why does filmgrain need to die?
- Animats 1y agoBecause it's noise. We got rid of interlaced TV. We got rid of the low-bandwidth color changes of NTSC. (NTSC video can only go through the color gamut about ten times per scan line, which is why colored text on NTSC is truly awful.) We got rid of projector film transport jank. (Except for really bad Youtube videos which use a filter to produce fake film transport jank.) Nobody wants any of those back.
- deleted 1y ago[deleted]
- jccalhoun 1y agoI remember years ago when digital projection was just becoming the norm. I saw a movie (I don't remember which one) and during the opening scene I remember thinking "why are the credits jittering around? Oh. This is actually being projected on film!" I'm in my early 50s so I remember film quite well. Just like vinyl or cassettes, I ain't going back and unless it is an artistic choice I don't want films to emulate what I consider to be an inferior technology.
- kevinsync 1y agoOk, 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 DVD) .. and I'm shocked that Netflix doesn't just have this built into their Apple TV app or whatever. I'm shocked PLEX doesn't have it! (that I know of) I made a comment on a different post about imagining a world where local AI/LLM/whatever does some favorable processing for you, by you, on your device, of web content, to enhance your experience. I really believe media (streamers all the way down to open source devs) need to begin to incorporate whatever's out there that reduces friction and increases joy. It's all out there already! The heavy lifting has been done! Just make Family Matters look like how it looked when I was locking in on a Friday night for TGIF LOL [0] https://github.com/mausimus/ShaderGlass https://github.com/mausimus/ShaderGlass
- maxglute 1y ago> Shaderglass + NewsRadio I just want to say this is brilliant suggestion. Shit tier DVD rips of Newsradio really be elevated on shaderglass.
- starchild3001 1y ago[flagged]
- ghghgfdfgh 1y agoWhat is the motivation for writing HN comments with AI?
- atulvi 1y agoLow quality AI comment
- m3kw9 1y agoIs film grain a nostalgia effect? If kids grew up without seeing film grain, how would they feel about it?
- CharlesW 1y ago> Is film grain a nostalgia effect? Film grain simulation can be an effect, but that's not the primary application being described here. As @ricardobeat succinctly put it elsewhere in this post, this process usually supports "a reproduction of the original grain pattern, compressed separately from the underlying image content. The result is closer to the original picture than the denoised/compressed version". > If kids grew up without seeing film grain, how would they feel about it? Film isn't quite dead yet, with ~7% of features in 2025 still being shot on film and maybe 1% more taking the digital→film→digital (a.k.a. "analog intermediate") route. Unless their media diet is all super-recent and low-quality, even today's kids will have most likely seen many movies shot on film with visible grain. Popular candidates would include the Harry Potter franchise, most episodes of the Star Wars franchise, early Marvel movies, many animated Disney and Studio Ghibli features, etc.
- unit149 1y ago[dead]
- Pesthuf 1y ago>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 That's one hell of an exaggeration. But even if that was true, I don't see how removing it, then adding fake on in would help. That entire sentence really has a "written by ChatGPT" smell. >It's not just X. It's Y".
- liampulles 1y agoThe key point some people are missing here is that removing noise from a video before compression makes it more compressible. So if you compare a video compressed without denoising/degrading at bitrate X to a video that was filtered and then compressed at bitrate X with "fake noise" added later, then the latter will have edges and details that the former doesn't. The principle of post-processing videos to add noise or sharpening is something that desktop media players have supported for years, some are even reasonably good at it.
- illiac786 1y agoExactly. Everyone is going on about grain quality but are in fact comparing wheat and spelt (if I may). What matters to Netflix is the bandwith/quality ratio, that’s it. Removing noise before and adding it in software at playback time will produces a significantly better result, at similar bit rate. Because compressing noise produces horrible results.
- PaulHoule 1y agoAs a mirrorless photographer I use a lot of processing to create a unique look. If I at all can, I set the aperture really small, use denoising, sharpening and color grading. If people think my photo came out of an old book that’s great. I have looked at various “film look” filters and so far haven’t found one I like. When I think “film grains” I think of irregular shaped crystals, but most of the fake film grain I’ve seen makes a square pixel grain which doesn’t convince me at all. My understanding is the grain already exists before the image is shot in the sense that the films has irregular “pixels” which respond more or less because of shot noise and variation of the grain and I haven’t found anything that really simulates this.