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0 pointscrazygringo5y ago0 comments

If you're talking about a beautifully mastered Blu-Ray, then that might be true.

But given how aggressively YouTube compresses videos, watching in 4K can provide a huge improvement over 1080p even if your screen only has, say, 1,600 lines like my MBP does, instead of the 2,160 lines that 4K actually produces. It's really about the clarity of textures and how lifelike they are -- it's very noticeable. Of course, this also assumes you have good vision.

I also don't think anyone's too worried about "wasting computing power" here for a short video.

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cbsmith5y ago· 2 in thread

That's curious. My observation has been that most of the streaming services have really high compression ratios with 4k streams. With videos like this one, which are built from still images, I imagine you still get significant improvements in quality, but for content that isn't so easily compressible (e.g. action movies), I've seen significant effects from compression in 4k streams as compared to "regular" 4k source material.

As far as "wasting computing power"... I hear some people play video games while watching movies... on the same machine. So that's probably what that is about.

crazygringoOP5y ago

That's exactly what I'm saying, though.

Because YouTube (like other streaming services) aggressively compresses both 1080p and 4K, but the 4K version still has a much higher bitrate, watching the 4K stream on a 1080p monitor will be significantly better quality than watching a 1080p stream on a 1080p monitor.

I'm not saying you won't see any compression artifacts at all, of course if it's an scene you will. But the 4K version is still noticeably way better than the 1080p one, even in an action scene. It's a higher bitrate so there's more detail no matter what.

cbsmith5y ago

Yeah, what I'm saying is that because the 4k streams are trying to convey more entropy than the 1080p streams, I've observed that even though their bitrate is higher, the resultant compression effects are far more severe, to the point where the overall experience is better with 1080p, sometimes even if you have access to the full 4k resolution. I've seen similar effects with audio content (after a certain point, increasing sampling rate significantly more than bitrate has a deleterious effect).

From an information theory perspective, you are obviously correct that there is more information in the 4k streams and therefore you will get more detail from them. My observation however has often been the opposite.

My attempt to rationalize leans towards notions that the lossy compression techniques we use with video codecs still have significant impedance with the "compression" in our neuro-opthalmologic system.

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