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Mars images rendered in 4K [video]

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Re: Mars images rendered in 4K [video]

#71
post #63

Fascinating photos. I hope, sometime in my life, humans will be able to go. If the rover can stream to the orbiter at 2mb/s, would it be possible stream video to the orbiter and have it save in its buffer? Then it'd transfer to Earth later on?

But only for 8 minutes according to the voice over. Which would come down to 960MB in an ideal scenario (2 MB/s * 8 * 60s).

Re: Mars images rendered in 4K [video]

#72
post #70

Interesting facts that I didn't know before seeing this video: - The opportunity rover captured a barren scene which was named Rub Al Khali (Yes! On Mars!), named after the Rub Al Khali desert area which touches UAE, Saudi, Oman and Yemen. (1) (2) - The video says that Mars rovers send back images (not videos) and then those images are stitched together to create videos, because "nothing ever moves on Mars". But I wo…

Mars is constantly moving. There are wind storms, dust devils, ice melting, all kinds of things. Here's a dust devil https://www.youtube.com/watch?v=k8lfJ0c7WQ8 (again, it's still images to make a video) but not because "nothing ever moves on Mars"! Mars is constantly shifting and changing with its weather and seasons. Ice caps freeze more, and ice caps melt more, water or other liquid flows down hills when it gets w…

When something is quoted like that it usually means it's a reference to something, not a literal statement. In this case I'm guessing it's a play on "Nothing ever happens on Mars" by the Spinal Tap guy.

Re: Mars images rendered in 4K [video]

#73
post #16
post #2

In my youtube quality menu, it only goes up to 1080p. Is this really 4K?

In 9/10 cases you don't see the difference anyway unless you are actually on a very large screen and you don't mind wasting the extra computing power.

I believe it's worth watching 4k even on a 1k monitor, because due to chroma sub-sampling there is actually information visible even at the lower resolution.

Re: Mars images rendered in 4K [video]

#75
post #18

Earlier quoted context omitted.

I was experiencing that on Safari, then switched to Chrome and it now shows 4K.

Confirmed. Once I switched to Chrome, I could see the 4K quality option.

2160p also shows up for me on Firefox & Brave.

Golden rule: don't use Safari for Youtube.

Re: Mars images rendered in 4K [video]

#76
post #16

Earlier quoted context omitted.

In 9/10 cases you don't see the difference anyway unless you are actually on a very large screen and you don't mind wasting the extra computing power.

I believe it's worth watching 4k even on a 1k monitor, because due to chroma sub-sampling there is actually information visible even at the lower resolution.

Do the video decoders take advantage of this? I was under the impression they did not.

Re: Mars images rendered in 4K [video]

#77
post #71
post #63

Fascinating photos. I hope, sometime in my life, humans will be able to go. If the rover can stream to the orbiter at 2mb/s, would it be possible stream video to the orbiter and have it save in its buffer? Then it'd transfer to Earth later on?

But only for 8 minutes according to the voice over. Which would come down to 960MB in an ideal scenario (2 MB/s * 8 * 60s).

Is that megabits or megabytes? Usually lowercase denotes bits, so I think you'd divide that total data size by eight to get 120MB. With a good codec 2mbit/s is probably enough for low-motion SD or 720p video.

Re: Mars images rendered in 4K [video]

#78

Earlier quoted context omitted.

So they put in effort to make this, you consume it for free and then you complain that they can monetize it? OK.

The comment was about when videos are artificially slowed down, not about monetisation per se.

But they make it slow to monetize it.

I got the point, but it's not really fair towards content creators.

Re: Mars images rendered in 4K [video]

#79

Earlier quoted context omitted.

So they put in effort to make this, you consume it for free and then you complain that they can monetize it? OK.

Yes, people should be able to complain about things that are annoying and damage their experience. In this case, 10 minutes is an arbitrary time and the OP is arguing that this arbitrary number for monetization results in poorer quality videos.

Just in this case I'd complain that it's not 30 minute Mars imagery I 4k :)

Re: Mars images rendered in 4K [video]

#80
post #16

Earlier quoted context omitted.

In 9/10 cases you don't see the difference anyway unless you are actually on a very large screen and you don't mind wasting the extra computing power.

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…

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.

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