HN Distilled

Essential insights from Hacker News discussions

AV1@Scale: Film Grain Synthesis, The Awakening

Original Article

Hacker News Discussion

Here's a summary of the themes from the Hacker News discussion, with supporting quotes:

The Ambiguity and Subjectivity of "Realism" and Aesthetic Preference

A significant portion of the discussion revolves around the idea that film grain contributes to realism, but many users question this assertion. The debate highlights how our perception of realism is shaped by familiarity, artistic intent, and even our own biological processes.

  • "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" - jedbrooke
  • "But there is no grain in reality, so it does the opposite" - eviks
  • "Well ackchually -- illumination is inherently random, so all time-bounded captures of a scene (including what your eyes do) are subject to shot noise" - meatmanek
  • "People 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... If you're going to have them anyways you might as well make a conscious choice as to how they add to the overall design of the structure." - observationist and throw0101d (on architectural elements vs. film grain)
  • "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." - observationist
  • "The grain is there to hide the ugly smudge. that's the question they rather you didn't ask" - dylan604 (commenting on the function of grain in compression)

Film Grain as a Technical Tool and Artefact Concealer

Several users point out the practical, technical benefits of film grain, particularly its ability to mask compression artifacts and enhance perceived detail in a digitally processed image.

  • "The 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." - GuB-42
  • "Maybe it adds some high frequencies that compression often washes out, or maybe acts like some kind of dithering." - GuB-42
  • "Video 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." - plastic3169
  • "It is useful beyond just aesthetics. It tends to increase perceived sharpness and hides flaws like color banding and compression artifacts." - dperfect
  • "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." - dperfect

The Human Eye and "Grain"

The discussion touches upon whether the human eye itself perceives "grain" or visual noise, drawing parallels to visual snow and the inherent randomness of light capture.

  • "Mine do, at least when it's very dark" - tiluha (referring to eyes having grain)
  • "Yeah I've had visual snow, I think only when I'm tired, stood up too fast, dehydrated, etc." - 01HNNWZ0MV43FF
  • "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." - dinfinity
  • "Psst. Your eyes have plenty of grain. It's called visual acuity and sensitivity." - unnamed user
  • "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." - GuB-42

Familiarity, Nostalgia, and Learned Aesthetic Cues

A strong theme is that our appreciation for film grain (and other stylistic choices like 24fps) is heavily influenced by decades of exposure, leading to a learned association of these elements with a particular viewing experience and nostalgia.

  • "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"." - observationist
  • "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." - observationist
  • "This 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”." - Kina
  • "grain 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." - sneak
  • "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... Would reinforce that grain = good while not being necessarily the case..." - dmbche
  • "It is a neat tool to lower sharpness!" - dmbche
  • "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... and HAD grain." - dmbche

The Debate on Client-Side vs. Server-Side Grain Synthesis and User Control

The technical implementation of Film Grain Synthesis (FGS) for streaming, particularly by platforms like Netflix, sparks a debate about creative intent, bandwidth efficiency, and user preference, with many advocating for the ability to toggle grain on or off.

  • "Provide distributors with a noiseless source plus grain synthesis parameters. Bonus: many viewers would welcome an option to turn it off." - rainworld
  • "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" - dylan604
  • "Why? If you're wasting half your bits transmitting data that could be effectively recreated on the client for free, isn't that wasteful? ... If you could make this work, why wouldn't you?" - Wowfunhappy
  • "I realize some of this might not reflect reality--grain doesn't cost half your bitrate, and locally-reproduced grain doesn't look quite right--but travel down the hypothetical with me for a moment. If you could make this work, why wouldn't you?" - Wowfunhappy
  • "But if someone actively decides 'I want to watch this without the grain for my own viewing experience'... okay? You do you. I will further acknowledge that I would in fact be that person. I hate grain." - Wowfunhappy
  • "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." - Wowfunhappy
  • "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" - dylan604
  • "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 [denoised version with synthesized grain]. 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." - dperfect
  • "It’s really just a form of dithering." - isx726552
  • "Fake grain really disgusts me." - sharpshadow
  • "The 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." - smusamashah

The "Film Look" Beyond Grain

Some users argue that film grain is only one component of the "film look," and that other analog characteristics like highlight blooming and less sharp images are equally, if not more, important.

  • "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." - dylan604

The Evolution of Aesthetic Imperfections into Deliberate Artistic Choices

A recurring observation is how perceived flaws or limitations in older technologies often get reinterpreted and adopted as intentional aesthetic choices in later eras.

  • "ANY noticeable percieved "flaw" in any creative media will eventually become an aesthetic choice." - jrm4
  • "When you ran out of things to innovate on." - vachina (commenting on why trends like grain might persist)
  • "I love grain! 16mm vibes" - shashanoid

Concerns About Lossy Compression and Digital vs. Analog Acquisition

There is a sentiment among some users that digital media, even with attempts to emulate film characteristics, fundamentally differs from analog film due to compression and the inherent nature of digital sensors versus film.

  • "kelsey98765431: happier 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: agree"
  • "ConanRus: Everything 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."
  • "It'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." - _bent