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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

#21

Post by iwasakabukiman »

purerandomness wrote: post #7
2bitencryption wrote: post #4

Earlier quoted context omitted.

Instead of one optimization profile for a whole movie, Netflix is detecting when the shot of a movie changes (the camera "cuts" from one shot to another) and beginning a new optimization profile specifically for the content of that shot. At least, that is my understanding.

That sounds so intuitive that I want to follow up with the question: Why isn't this the default? Is detecting a cut particularly difficult?

Traditionally, you just encode the video with a new frame every X frames, regardless of shots.

It might sound trivial, but it is still extra computational work to figure out when the shot changes.

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

#22

Post by charrondev »

adrr wrote: post #18
charrondev wrote: post #5

That seems like a pretty impressive achievement! Question for anyone here: What do you use to play 4K/HDR? 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). The sound quality is also noticeably worse on my set with it (it doesn’t seem to be able to do direct pass through…

HDR10 is fine right now. I don’t know of any tv that has a 12 bit capable panel or can create over 1000 nits brightness. HDR10 supports 4,000 and Dolby vision supports 10,000. TVs need to get a lot better before Dolby vision makes a difference.

I wasn’t aware! I have an LG B7 and it’s maximum brightness is like 800nits, and even that seems too bright a lot of the time, so I turn on “power save” mode which dims it by about half. No wonder I never noticed any difference.

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

#24

Post by charrondev »

duhi88 wrote: post #19
charrondev wrote: post #5

That seems like a pretty impressive achievement! Question for anyone here: What do you use to play 4K/HDR? 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). The sound quality is also noticeably worse on my set with it (it doesn’t seem to be able to do direct pass through…

I have a Vizio Quantum X and a PS4 Pro both work great. YouTube videos show the occasional dropped frame on the Vizio app, and generally 0 dropped frames on the PS4. I don't have the best speakers or room acoustics, but I can't complain about the sound.

I have a PS4 which won’t do the trick, but was planning on a PS5 when it comes out so maybe that’ll be the answer.

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

#25

Post by hn_check »

wtallis wrote: post #14

A lot of those graphs seem to show that video quality at 1920x1080 is going down significantly. Does that mean you now need to be on their most expensive plan and using one of their approved devices/platforms to continue receiving the same video quality, now only obtainable with 2560x1440 and higher resolutions?

The chart does not see to show every bitrate for every target resolution, but rather is show where the 4K stream would have to drop to a lower resolution given insufficient bandwidth.

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

#26

Post by zaksoup »

charrondev wrote: post #5

That seems like a pretty impressive achievement! Question for anyone here: What do you use to play 4K/HDR? 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). The sound quality is also noticeably worse on my set with it (it doesn’t seem to be able to do direct pass through…

I'm using a 2018 model-year Samsung 4k smart TV. I'm pretty sure it's running Tizen OS and it's surprisingly good. I'm doing sound out via ARC to a Sonos Beam in a 5.0 with the IKEA/Sonos speakers as rears. So far my only complaint is that the Tizen Plex app doesn't play nice with DTS audio even though the TV has a native DTS decoder.

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

#27

Post by charrondev »

teilo wrote: post #15
charrondev wrote: post #5

That seems like a pretty impressive achievement! Question for anyone here: What do you use to play 4K/HDR? 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). The sound quality is also noticeably worse on my set with it (it doesn’t seem to be able to do direct pass through…

I use the native apps in my Samsung Q70 TV. They are really good, and I rarely find a need to use my 4K Apple TV anymore. Even the Samsung Apple TV apps, and the AirPlay 2 support is excellent. As it is, Apple has screwed up HDR on the 4K so badly that it's very difficult to make it work smoothly without also screwing up HDR on other devices.

The difficulty for me is that my TV doesn’t have enough HDMI inputs (LG B7). I use 7 through my yahamah receiver, but have struggled to get ARC (audio from the TV through the sound system) to do-exist with also also having everything else go through the receiver.

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

#28

Post by hn_check »

charrondev wrote: post #5

That seems like a pretty impressive achievement! Question for anyone here: What do you use to play 4K/HDR? 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). The sound quality is also noticeably worse on my set with it (it doesn’t seem to be able to do direct pass through…

"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 unnoticed?

My LG 4K TV has fantastic Netflix, Prime, and Disney+ clients. HDR, 4K, etc.

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

#29

Post by charrondev »

wtallis wrote: post #14

A lot of those graphs seem to show that video quality at 1920x1080 is going down significantly. Does that mean you now need to be on their most expensive plan and using one of their approved devices/platforms to continue receiving the same video quality, now only obtainable with 2560x1440 and higher resolutions?

How’d you get that out of the article? I read it as scores the board, you’re getting better quality at a lower bit-rate. They talked about being able to serve 1080p at the same bitrate they were serving 720p (where they talked about mobile devices).

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

#30

Post by fock »

radley wrote: post #20

> Sometimes we ingest a title that would need more bits at the highest end of the quality spectrum — even higher than the 16 Mbps limit of the fixed-bitrate ladder. From just a cursory inspection using my Apple TV 4K, 12 Mbps is their target bitrate but their ceiling was ~16 Mbps. That's still only a third of what AppleTV+ offers (36/48) and only 2/3 of Disney+ (18/24). Netflix is still higher than Prime Video (10/14…

I just stopped caring, bought a Blu-Ray drive, which works fine under Linux nowadays and can enjoy 30Mbps FHD-encodings where I can just hit pause and have a photo-like still (everything sharp, no blocky shadows). Oh and yes, I also can buy 2 discs/per month of actual good movies I really want to watch (who has time for more than that anyway?) for what Netflix would like to charge me...
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