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Netflix is now doing per-shot encoding for UHD content

netflixtechblog.com

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Re: Netflix is now doing per-shot encoding for UHD content

#171

Post by TazeTSchnitzel »

It sounds like Netflix might not be doing the horrible thing YouTube and Twitter do where they treat low-resolution (e.g. standard definition) content as being less deserving of bitrate with only higher resolutions allowed to climb the bitrate ladder? For those sites I have to upscale SD content to HD resolutions when uploading just for it to be allowed a less paltry bitrate.

I fear people who grow up in the age of streaming might not realise that DVDs had good video quality because streaming services seem to hate SD content.

> As a side note, we do have some additional points, not shown in the plots, that are used in resolution limited scenarios — such as a streaming session limited to 720p or 1080p highest encoding resolution. Such points lie under (or to the right of) the convex hull main ladder curve but allow quality to ramp up in resolution limited scenarios.

Re: Netflix is now doing per-shot encoding for UHD content

#172

Post by jiggawatts »

dimnsionofsound wrote: post #59
sjwright wrote: post #36

Earlier quoted context omitted.

The jittering is caused by the Apple TV defaulting to 60p frame rate for all content. But if you turn on “match frame rate” the jittering goes away.

Before I turned that on, watching BBC documentaries in 25 FPS the judder was very noticeable on panning shots. Definitely worth enabling if your device supports it.

At least Apple TV supports this feature, even if it's off by default.

Google simply "decided" for Chromecast users that 60 Hz is fine and that nobody needs 24 fps or 50 fps content.

Re: Netflix is now doing per-shot encoding for UHD content

#173

Post by httpsterio »

Without understanding all of the technical details, am I the only one who finds Netflix's quality on Android insufferable? Technically, I guess it's Full HD but the packing is so aggressive that any scenes with just a bit darker sections will instantly be blocky and pixellated. Is there any way around it? Honestly it's not worth paying for as it's almost unwatchable.

Re: Netflix is now doing per-shot encoding for UHD content

#175

Post by iso1210 »

bscphil wrote: post #110
zbobet2012 wrote: post #107

Earlier quoted context omitted.

> 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. No they have not made it worse. 1080p encoded at lower bitrate can look better than 720p at a higher bitrate. Or vice versa. Even to the trained eye. It depends on the scene…

> No they have not made it worse. 1080p encoded at lower bitrate can look better than 720p at a higher bitrate. Or vice versa. Even to the trained eye. It depends on the scene dynamics.* Well, of course that's correct. Take 1080p encoded at 100 Mbps and 720 encoded at 300 Mbps, I guarantee you that 1080p wins every time. :-) > In the ladders they posted (called a RD chart) we can clearly see they have made a better s…

> Well, of course that's correct. Take 1080p encoded at 100 Mbps and 720 encoded at 300 Mbps, I guarantee you that 1080p wins every time. :-)

No it doesn't. Depending on the distance from the screen and indeed the screen resolution, you won't benefit from the extra 1080p resolution, but you could benefit from the extra bits. 1080p60 is 3.7GBit uncompressed with 10 bit 444, so that's 37:1 compression. 720p60 is 1.7gbit, or 5.5:1 compression, so far fewer compression artifacts.

Re: Netflix is now doing per-shot encoding for UHD content

#176

Post by dimensi0nal »

rblatz wrote: post #160
saxonww wrote: post #158

Earlier quoted context omitted.

Edge supports PlayReady in addition to Widevine. PlayReady is what gates the higher quality stream. No idea what the technical reason is for this.

Honestly the whole thing is stupid. 4k videos of everything on Netflix are available on the high seas. What’s the point?

Right now stripping Netflix's 4K DRM is possible but it requires buying a new Nvidia Shield TV for every release you do. If you could strip the DRM without buying expensive hardware every time people might be slightly quicker to release the entire 4K Netflix catalog.

Re: Netflix is now doing per-shot encoding for UHD content

#177

Post by gruez »

jiggawatts wrote: post #146
gruez wrote: post #109

Earlier quoted context omitted.

>Also: I'm reasonably convinced that NetFlix is violating the law, at least in Australia, by advertising that their content is 4K and then arbitrarily blocking access to the 4K streams. This is called "bait & switch", and the fines are eyewatering, even for large corporations. Nah, they have their asses covered. I went to the website and tried to sign up, and at the first mention of 4k (when you're choosing a plan),…

One could make the argument that this is purposefully deceptive. The phrasing makes it sound like external conditions, outside of Netflix's control are the reason 4K may not be available. The reality is they sell two subscription levels: 4K and a HD-only one, but then after you've given them your money, they outright block access to 4K streams on a device that is physically capable of playing the stream. I can play 3…

>The phrasing makes it sound like external conditions, outside of Netflix's control are the reason 4K may not be available.

I agree that the phrasing isn't the clearest, but it's not like the actual requirements aren't available. A search for "netflix 4k" turns up this page as the first result: https://help.netflix.com/en/node/13444, which clearly lists what the requirements are.

Re: Netflix is now doing per-shot encoding for UHD content

#178

Post by hn_check »

AnssiH wrote: post #170
hn_check wrote: post #28

Earlier quoted context omitted.

"I have an Apple TV 4K, which can do 4K Dolby Vision playback and looks ok, but the Apple TV tends to have some jittering when streaming certain shows (very noticeable in panning shots of animation)." How don't more people complain about this? I avoid streaming on the Apple TV because it does some sort of bizarre framerate thunking that is just brutal for panning. Do so few people use the product that it just goes un…

I believe most people just don't notice the judder, and many of the rest don't care. E.g. it took a lot of convincing to get Google to add "use 50p output" to Chromecast settings years ago (and that didn't fix 24p of course, just European 25p/50p which is more severely affected). Also, most high-end TVs are able to recover the original 24p (or other) frame rate and thus remove the judder by using specific settings: h…

"I believe most people just don't notice the judder, and many of the rest don't care"

This is probably the case. DAZN took over NFL streaming in Canada and for the first two years seemed to use their existing European soccer processing chain (they might still --- I gave it a try to years straight and then gave up). So the 60/30 NFL stream was re-encoded to 25/50, and then on playback on my set would be displayed at 30/60. It was brutal, and even if displayed at 25 or 50 FPS was still brutal because they were seriously corrupting the NFL stream.

I tried it across a number of devices -- AppleTV, Chromecast, different TVs, pads, laptops -- and it was just unbelievably intolerable to me. Every panning pass was the horrendous juddering mess. Yet somehow no one seemed to have a problem with this! In discussions it seemed to be a non-issue.

Re: Netflix is now doing per-shot encoding for UHD content

#179

Post by FullyFunctional »

bscphil wrote: post #98
joshschreuder wrote: post #94

Earlier quoted context omitted.

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 -…

Actually I first saw it on a plane and wondered how we have gotten to this stage where obviously garbled video is ok to give to paying customers. Yes, more bits will solve this, bit it’s still a great example that breaks encoding assumptions.

Re: Netflix is now doing per-shot encoding for UHD content

#180

Post by laurencerowe »

namibj wrote: post #157
laurencerowe wrote: post #76

Earlier quoted context omitted.

In case you are using Google/Cloudflare DNS try switching back to Comcast's DNS servers so you get directed to a Netflix Open Connect box within their network.

Google DNS supports EDNS-subnet info, and should work just as well as Comcast's DNS for Netflix. Cloudflare won't, though.

Do you know if this used to be an issue that is now resolved? The poor streaming quality I experienced was watching Netflix over Comcast cable internet with Google DNS several years ago. It was night and day different after changing DNS resolvers back to Comcast, though I guess it could have been a coincidence.
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