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I reverse-engineered Netflix's 4K restrictions

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Re: I reverse-engineered Netflix's 4K restrictions

#81

Post by bobdvb »

Retr0id wrote: post #54
nitwit005 wrote: post #47

Earlier quoted context omitted.

Netflix does charge more for 4k, so they simply pass along the cost: https://help.netflix.com/en/node/24926

Netflix still saves money when someone watches in a lower resolution.

There's a fine line, reduce quality too far and customer satisfaction drops. Some customers will have a higher tolerance to dropping quality than others, but you've got to draw the line somewhere.

So you do studies, you look at the impact of quality changes to customer churn and then you move the line appropriately.

Re: I reverse-engineered Netflix's 4K restrictions

#82

Post by yencabulator »

karim79 wrote: post #43
Cyph0n wrote: post #25

Earlier quoted context omitted.

For Netflix specifically; it’s because the groups that rip 4K content from Netflix burn a device (i.e. a Widevine L1 key). This is why they typically release 4K Netflix shows in batches. Here is a good thread on the topic: https://www.reddit.com/r/Piracy/comments/17ez7mi/how_come_it...

What I've noticed about Netflix's supposedly 4k content is that it looks like crap compared to the same show downloaded through illicit means (and viewed on Plex or something else). What's the deal with Netflix's not-very-good 4k streams? Colour quantization or something? It's not just a one-off, why do 4k netflix shows look like rubbish compared to a moderately encoded whatever from bittorrent?

Semi-informed guess: Even when the rip comes from the same source (and not e.g. Blu-ray), they have a blazing fast internet pipe and/or a custom client that locks into the maximum bitrate -- while your residential connection and/or the local PoP's available capacity make your stream use a lower bitrate.

Re: I reverse-engineered Netflix's 4K restrictions

#83

Post by compsciphd »

Cyph0n wrote: post #25
hermanzegerman wrote: post #11

I never get why those idiots make it harder for paying customers to watch content, than for those just torrenting it. It's the same with Amazon Prime Video which will get me a black screen on Linux or force me to SD Quality, while the torrented Movie runs just fine in 4K

For Netflix specifically; it’s because the groups that rip 4K content from Netflix burn a device (i.e. a Widevine L1 key). This is why they typically release 4K Netflix shows in batches. Here is a good thread on the topic: https://www.reddit.com/r/Piracy/comments/17ez7mi/how_come_it...

and its easy enough to figure out who ripped the web-dl, because you can have each frame copied into 2 slightly different but functionally identical versions (or perhaps just a longer GOP, but still the same). Create 32 of these sets of 2 (i.e. bits, or even do it for every 32 sets in the video) and assign every user a unique set of 32 "bits" and you'll have the ability to uniquely identify every web-dl (as by definition they aren't modifying the streams) to the user who downloaded it and just a cost of 1x the storage vs not doing anything.

Re: I reverse-engineered Netflix's 4K restrictions

#84

Post by coppsilgold »

sparklysoup wrote: post #72
coppsilgold wrote: post #58

Earlier quoted context omitted.

> To what extent does this watermarking survive transcoding? Would not transcoding multiple times possibly affect it? They are designed to survive being recorded by a phone at an angle. The embedding is only 1-bit per segment which can be multiple megabytes. > Why? Tardos codes scale as the square of the number of traitors times a constant. For example, a movie would typically have 2000 segments -> 2000 bits of encod…

> They are designed to survive being recorded by a phone at an angle. Any idea what this looks like? I assume it's not visible to the human eye, but being able to survive this level of degradation is quite impressive.

My understanding is that it has gotten fairly complex. Don't know if they still use this particular facet but look at the Fourier-Mellin transform: https://sthoduka.github.io/imreg_fmt/docs/fourier-mellin-tra...>

They don't use the highest frequencies as those watermarks are easy to obliterate, and they don't use the lowest frequencies as those would noticeably affect quality, the focus is generally on the mid range frequencies. However for A/B watermarking in particular which involve 1-bit watermarks, low frequencies may actually be fair game.

Keep in mind that when embedding watermarks of significant size (>100 bits) as for example if you want to create a camera that includes the serial of the device in every photo, error correcting codes would also be used. For 1-bit watermarks the error correction is likely ad-hoc and involves constructing some mathematical object (for example, a few real numbers derived from frames of a segment) which remains approximately fixed through transformations, you can afford to be wasteful.

Re: I reverse-engineered Netflix's 4K restrictions

#85

Post by jhanschoo »

dfajgljsldkjag wrote: post #63

Hello HN, I have an important thing to point out: THIS EXTENSION DOES NOT WORK! let me put it another way: THIS EXTENSION DOES NOTHING USEFUL! The author did not reverse engineer anything. He simply asked Claude Code to make this without testing or verifying any of the outputs. The author did not check if the extension actually works. He simply asked Claude Code to make this without testing or verifying any of the ou…

The submission title is indeed correct, but the README there is indeed so bogus. What's the point even discussing environments that don't have Widevine L1?

Re: I reverse-engineered Netflix's 4K restrictions

#86

Post by direwolf20 »

dfajgljsldkjag wrote: post #63

Hello HN, I have an important thing to point out: THIS EXTENSION DOES NOT WORK! let me put it another way: THIS EXTENSION DOES NOTHING USEFUL! The author did not reverse engineer anything. He simply asked Claude Code to make this without testing or verifying any of the outputs. The author did not check if the extension actually works. He simply asked Claude Code to make this without testing or verifying any of the ou…

Thank you for your warning. I checked the code and I don't see how this could possibly work. If not for your warning at the top of the comments, I would have assumed it worked as intended, and congratulated the author on their successful project of deshittification.

Re: I reverse-engineered Netflix's 4K restrictions

#87

Post by direwolf20 »

hermanzegerman wrote: post #11

I never get why those idiots make it harder for paying customers to watch content, than for those just torrenting it. It's the same with Amazon Prime Video which will get me a black screen on Linux or force me to SD Quality, while the torrented Movie runs just fine in 4K

It's a legal contractual requirement with the companies who provide the content.

Re: I reverse-engineered Netflix's 4K restrictions

#88

Post by direwolf20 »

karim79 wrote: post #43
Cyph0n wrote: post #25

Earlier quoted context omitted.

For Netflix specifically; it’s because the groups that rip 4K content from Netflix burn a device (i.e. a Widevine L1 key). This is why they typically release 4K Netflix shows in batches. Here is a good thread on the topic: https://www.reddit.com/r/Piracy/comments/17ez7mi/how_come_it...

What I've noticed about Netflix's supposedly 4k content is that it looks like crap compared to the same show downloaded through illicit means (and viewed on Plex or something else). What's the deal with Netflix's not-very-good 4k streams? Colour quantization or something? It's not just a one-off, why do 4k netflix shows look like rubbish compared to a moderately encoded whatever from bittorrent?

All video encoders have bit–rate — target number of encoded bits per second — as a tunable knob. Lossiness is compensated to match the target bit–rate. When a video is encoded with a lower bit–rate, it produces a smaller file that looks worse. Resolution almost doesn't matter, if your bit–rate is so low that the encoder doesn't have a chance of encoding pixel–level detail.

Bittorrent pirates may source shows from Netflix but they may also source them from other places with higher bit–rate encodings.

Re: I reverse-engineered Netflix's 4K restrictions

#89

Post by apparent »

Retr0id wrote: post #71
nitwit005 wrote: post #69

Earlier quoted context omitted.

Yes, but what they care about is profits. People aren't going to pay for the expensive plan if they can't actually use the features of it.

Most people who aren't getting proper 4K don't even notice.

Bingo. I mostly have watched Netflix for the last decade and recently tried Apple TV. It looks so much crisper. I didn't realize what I was missing.

Re: I reverse-engineered Netflix's 4K restrictions

#90

Post by direwolf20 »

bigwheels wrote: post #36
Cyph0n wrote: post #25

Earlier quoted context omitted.

For Netflix specifically; it’s because the groups that rip 4K content from Netflix burn a device (i.e. a Widevine L1 key). This is why they typically release 4K Netflix shows in batches. Here is a good thread on the topic: https://www.reddit.com/r/Piracy/comments/17ez7mi/how_come_it...

Thank you for sharing the breadcrumb~ How does Netflix detect "suspicious" activity? Does $NFLX allow 4k streaming over GrapheneOS? If so, could you pin a different certificate and do some HTTP proxy traffic manipulation to obfuscate the device (presumably an Android phone) identity or otherwise work around the DRM? I want to understand more about this but unfortunately the reddit thread is bits and pieces scattered…

Netflix does not allow 4k streaming to GrapheneOS. Every piece of software and hardware in the signal chain must be Hollywood–approved, including your OS, GPU and monitor.
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