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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

#71

Post by ehsankia »

duhi88 wrote: post #60
purerandomness wrote: post #7

Earlier quoted context omitted.

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?

"Variable bitrate" encoding is a thing, which allows chunks of a file to be encoded at a higher or lower bitrate depending on how much is happening. I don't know exactly how it happens, but I assume that each chunk is determined by duration or size, while Netflix's new method determines each chunk by the content. In order for this to be the default, you'd need either humans, or pattern recognition algorithms to ident…

Right, these gains are mostly relevant when you have a relatively small library compared to how many views each item gets. For example this would probably not be worth it for Youtube, expect maybe on individual hyper popular videos. Every kb that Netflix can shave off of a popular movie means terabytes of bandwidth saved.

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

#73

Post by emerged »

mappu wrote: post #53

What exactly is shot-based encoding doing here? Even old XviD would reliably always insert a new I-frame / start a new GOP on a scenecut, and perform global rate optimization based on scene complexity within the target ABR parameters.

It sounds like the link between GOP and "shot" (single camera shot, presumably) is being done explicitly. I would've expected this to happen automatically through their production pipeline but I guess it wasn't.

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

#75

Post by ddingus »

baggy_trough wrote: post #63
chiph wrote: post #49

Earlier quoted context omitted.

And this is why I still get discs by mail. No dropouts, no unexplained drops in resolution, and it has a deeper catalog.

Scratched discs.

That almost always play nicely.

I still use optical media myself.

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

#76

Post by laurencerowe »

ProfessorLayton wrote: post #39
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'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…

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.

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

#78

Post by chii »

superkuh wrote: post #77

Uhh, so we're supposed to be happy about a variable bitrate and quality because it saves them some bandwidth? This isn't a feature for users it's a spin on a feature for the corporation.

> so we're supposed to be happy about a variable bitrate and quality because it saves them some bandwidth?

yes, because it saves you money - netflix could be increasing its subscription cost, or it could keep it down as the subscriber base grows, by using technique like this.

As long as you don't notice the difference, what's wrong with them saving some bandwidth?

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

#79

Post by zerocrates »

mappu wrote: post #53

What exactly is shot-based encoding doing here? Even old XviD would reliably always insert a new I-frame / start a new GOP on a scenecut, and perform global rate optimization based on scene complexity within the target ABR parameters.

Their older articles talk more about shot-based encoding specifically (and before that, per-title encoding) as they applied it to their non-4K content:

https://netflixtechblog.com/dynamic-optimizer-a-perceptual-v...

https://netflixtechblog.com/per-title-encode-optimization-7e...

A few relevant points:

- Their previous systems used fixed keyframes, so wouldn't be using scene-change detection at all (I presume this was to allow predictable chunking across different codecs)

- Since reliable streaming performance is a pretty big deal for Netflix, they probably have quite tight restrictions on VBR modes, which make them not work as effectively since they have less "room" to work with

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

#80

Post by zdw »

csdreamer7 wrote: post #17
arendtio wrote: post #12

Looks amazing and while I would like to enjoy such quality and am willing to pay for the premium plan (in fact I do already), I still can't watch the 4K content even in a world where I accept DRM modules in my browser, because some DRM plugins seem to be more equal than others.

Do we still need an Intel Kaby Lake or later CPU for 4K DRM decoding? (And Windows... forgot about that.) If so, Netflix is on the wrong side of the CPU war with AMD ascending.

On windows the DRM needed for 4k Netflix is PlayReady 3.0, which is supported on some cards after driver release 19.8.1: https://www.amd.com/en/support/kb/release-notes/rn-rad-win-1...
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