If only they would spend this much effort optimizing the quality of their screenwriting.
Are snarky comments like this really necessary or relevant to what's being discussed here?
Netflix is now doing per-shot encoding for UHD content
91–100 of 200 posts
Re: Netflix is now doing per-shot encoding for UHD content
#92That’s great. I’d love to see how they fare on this glitter which seems to destroy all compressors: https://m.youtube.com/watch?feature=youtu.be&v=MG_Lyg74UlU&t...
(I saw a similar problem with a famous monarch butterfly footage that I don’t have time to chase down)
Re: Netflix is now doing per-shot encoding for UHD content
#93It's really too bad that they haven't rolled this out for 1080p too. Their 1080p video quality is god-awful compared to Amazon. They may even have made it worse: from the "ladder" comparisons, it looks like they jump to higher resolutions at lower average bitrates now, so if you're stuck at 1080p you're going to be getting worse quality after these changes than before. Also, something that's kind of weird about all t…
> It's really too bad that they haven't rolled this out for 1080p too
Maybe they will? But it matters most for 4K performance, so that's where they started?
> encoders (x264, x265, etc) already have their own rate control algorithms
But they simply operate on a stream without taking future frames into account. This does a first entire pass on the film holistically to determine where keyframes should go and settings per-shot. It can't be backported to codecs because they work linearly.
> And even with that, depending on how sensitive you are to artifacts, some of the "optimized ladder" encodes still look worse.
The artifacts look worse only because it's zoomed in so crazy far. On a cinema screen, the additional sharpness will be clear, the artifacts not so much.
Re: Netflix is now doing per-shot encoding for UHD content
#94That’s great. I’d love to see how they fare on this glitter which seems to destroy all compressors: https://m.youtube.com/watch?feature=youtu.be&v=MG_Lyg74UlU&t... (I saw a similar problem with a famous monarch butterfly footage that I don’t have time to chase down)
Wow, that really was awful. Does this sort of thing require kind of like a specific optimisation to fix, or is there a general technique that would fix this and other stuff?
Re: Netflix is now doing per-shot encoding for UHD content
#95Earlier quoted context omitted.
I've noticed that ATV+ looks the best, which is much appreciated. However, what has been driving me insane with all these services is how the bitrate is completely inconsistent throughout, depending on network congestion. Every service I subscribe to will "automagically" lower the bitrate if the network can't handle it. Which is fine, I get it. The thing is, it's the only way to watch anything, and depending on the c…
Try doing "offline" downloads (with "highest" quality of course) in the app then casting to your TV. For true videophiles there's Kaleidescape but it's less valuable now that there are so many exclusive shows.
Airplay is limited to 1080p, and I don't think it includes HDR. Definitely not what I would call the pinnacle of quality.
I'm surprised that Apple TV apps don't allow you to download content, considering it is based on essentially iOS, but it is clearly a conscious choice.
Re: Netflix is now doing per-shot encoding for UHD content
#96It's really too bad that they haven't rolled this out for 1080p too. Their 1080p video quality is god-awful compared to Amazon. They may even have made it worse: from the "ladder" comparisons, it looks like they jump to higher resolutions at lower average bitrates now, so if you're stuck at 1080p you're going to be getting worse quality after these changes than before. Also, something that's kind of weird about all t…
> It's really too bad that they haven't rolled this out for 1080p too Maybe they will? But it matters most for 4K performance, so that's where they started? > encoders (x264, x265, etc) already have their own rate control algorithms But they simply operate on a stream without taking future frames into account. This does a first entire pass on the film holistically to determine where keyframes should go and settings p…
> This does a first entire pass on the film holistically to determine where keyframes should go and settings per-shot. It can't be backported to codecs because they work linearly.
Given that x264 already has a 2 pass mode, I don't see why that is necessarily the case. Even CRF mode uses mbtree by default, which is a pretty complicated rate control algorithm. x264 also has pretty intelligent keyframe determination, I almost always see I frames on scene transitions.
> On a cinema screen, the additional sharpness will be clear, the artifacts not so much.
I think it's probably the other way around. The closer you are to a screen, the more likely you are to notice increased resolution. But if there are large patches of the image full of artifacts, you'll be likely to see that even far away.
Re: Netflix is now doing per-shot encoding for UHD content
#97It's really too bad that they haven't rolled this out for 1080p too. Their 1080p video quality is god-awful compared to Amazon. They may even have made it worse: from the "ladder" comparisons, it looks like they jump to higher resolutions at lower average bitrates now, so if you're stuck at 1080p you're going to be getting worse quality after these changes than before. Also, something that's kind of weird about all t…
> It's really too bad that they haven't rolled this out for 1080p too Maybe they will? But it matters most for 4K performance, so that's where they started? > encoders (x264, x265, etc) already have their own rate control algorithms But they simply operate on a stream without taking future frames into account. This does a first entire pass on the film holistically to determine where keyframes should go and settings p…
Existing encoders have suported this for ages using multipass. In the first pass of multipass encoding, the input data from the source clip is analyzed and stored in a log file. In the second pass, the collected data from the first pass is used to achieve the best encoding quality. In video encoding, two-pass encoding is usually controlled by the average bitrate setting or by the bitrate range setting (minimal and maximal allowed bitrate) or by the target video file size setting.
The best way to understand why this is used is to think of a movie — when there are shots that are totally, absolutely black, like scene changes, normal 1-pass CBR encoding uses the exact same amount of data to that part as it uses for complex action scene. But by using VBR and multipass, encoder “knows” that this piece is OK with lower bitrate and that bitrate can be then used for more complex scenes, thus creating better quality for those scenes that require more bitrate.
Re: Netflix is now doing per-shot encoding for UHD content
#98That’s great. I’d love to see how they fare on this glitter which seems to destroy all compressors: https://m.youtube.com/watch?feature=youtu.be&v=MG_Lyg74UlU&t... (I saw a similar problem with a famous monarch butterfly footage that I don’t have time to chase down)
Wow, that really was awful. Does this sort of thing require kind of like a specific optimisation to fix, or is there a general technique that would fix this and other stuff?
Codecs with better understanding of what a complex scene looks like (and allocates more bitrate accordingly) will do better, and codecs that are better are blurring away details instead of blocking will do better as well.
Keep in mind this is on Youtube and uploaded by some shitty clip site, so it's a very biased example. In this case there are four lossy encode steps involved: master -> bluray -> clipsite's master -> Youtube encode. Youtube in particular has absolutely horrific, just inexcusably bad bitrate even at the highest quality they'll give you. I'd have to see what the original Bluray looks like in this case to see if there's really a problem worth worrying about here.
Re: Netflix is now doing per-shot encoding for UHD content
#99Earlier quoted context omitted.
I've noticed that ATV+ looks the best, which is much appreciated. However, what has been driving me insane with all these services is how the bitrate is completely inconsistent throughout, depending on network congestion. Every service I subscribe to will "automagically" lower the bitrate if the network can't handle it. Which is fine, I get it. The thing is, it's the only way to watch anything, and depending on the c…
On my phone it lets me download Apple TV+ content. The files are shockingly large compared to what Amazon Video downloads are. A 1 hr clip was maybe 800mb in prime, but a few gigabytes from apple. (I don’t have any on my phone atm, but a quick search is telling me episodes of “For all mankind” are ~4GB and an hour long) It looks noticeably better, a massive step up that is completely worth the extra bytes. On my desk…
> A 1 hr clip was maybe 800mb in prime, but a few gigabytes from apple.
Assuming x264 encoding, that sounds about right for 720p vs 1080p.
Re: Netflix is now doing per-shot encoding for UHD content
#100That’s great. I’d love to see how they fare on this glitter which seems to destroy all compressors: https://m.youtube.com/watch?feature=youtu.be&v=MG_Lyg74UlU&t... (I saw a similar problem with a famous monarch butterfly footage that I don’t have time to chase down)
The HBO intro’s white noise background is pretty bad too. Quite blocky and degraded.