When you watch 4K videos on a 1080p monitor is it really 4K quality?

[supyo]

I have downloaded dozens of 4K video samples and they all look stunning on my 1080p Samsung monitor. Way better than regular 1080p videos.

But is what i'm seeing really 4K quality? To me, it appears to be.

I have tested the same sample videos on 4K monitors and they look no better than what i'm seeing on my 1080p monitor.

Other than the 4K monitor having a higher native resolution what's the point if you're 1080p monitor can play back the same video quality?

I know gaming is another story however.

 

[gzboli]

If your video player downscales correctly you'll get supersampling with 4 pixels resolved down to one. It can look better than a 1080 source. Although the content creator could downsample and distribute at 1080 for the same effect with smaller filesize.

Haven't seen native 4K in person to comment on your other question.

 

[Dan_D]

You aren't getting 4k quality on a 1080P monitor.

 

[kevinlekiller]

If the ratio of resolution to bitrate is higher and the downscaler is good then maybe it could be higher quality?

If you take Youtube for example, 30fps 4K videos have a recommended bitrate of 45Mbps, 30fps 1080p videos have a recommended bitrate of 8Mbps, 4K is 4x the pixels of 1080p, so the ratio of bitrate to resolution is higher for the 4K videos (based on the recommended bitrates, I don't know if there's a max bitrate allowed), it would be equivalent to 11.25Mbps or so.

 

[supyo]

Download this 4K vid as an example: https://drive.google.com/file/d/0B35Le_BWIu3DS3dfd1NCVk5tZnM/view?usp=sharing

Its looks stunning on a 1080p display (thru VLC) and when I play it on a Seiki 4K monitor it looks the same, maybe a little bit worse. Could be the quality of the Seiki monitor though but the 4K video stream looks identical on the 1080p Samsung.

Edit: Don't watch it thru the youtube player, download it and watch in VLC or another video player. The video quality is amazing.

 

[Quix]

Download this 4K vid as an example: https://drive.google.com/file/d/0B35Le_BWIu3DS3dfd1NCVk5tZnM/view?usp=sharing

Its looks stunning on a 1080p display (thru VLC) and when I play it on a Seiki 4K monitor it looks the same, maybe a little bit worse. Could be the quality of the Seiki monitor though but the 4K video stream looks identical on the 1080p Samsung.

VLC just plays back videos at your screen resolution. It uses bi-linear filtering to resize the video so you're not getting 4K regardless of the source if you're using a 1080p monitor.

It's possible the 4K screen in question isn't very good, or that at the distance you're watching from the increased pixels aren't necessary.

 

[Epos7]

Other than the 4K monitor having a higher native resolution what's the point if you're 1080p monitor can play back the same video quality?

It can't play back the same video resolution. On smaller displays, the extra pixels 4K has might not be that noticeable. If the 1080p monitor has better image quality in general (color, contrast, etc) the video might look better on the 1080p display.

 

[supyo]

VLC just plays back videos at your screen resolution. It uses bi-linear filtering to resize the video so you're not getting 4K regardless of the source if you're using a 1080p monitor.

It's possible the 4K screen in question isn't very good, or that at the distance you're watching from the increased pixels aren't necessary.

I can understand that but why does 4K video look 4 times sharper than 1080p video on a 1080p monitor?

I am seeing a huge difference watching that above clip in 4K compared to 1080p on my Samsung monitor.

Is VLC making the video stream look 4 times better?

 

[Stoly]

You aren't getting 4k quality on a 1080P monitor.

Of course you do just ask AMD or nvidia about DSR and VSR

 

[x3sphere]

Download this 4K vid as an example: https://drive.google.com/file/d/0B35Le_BWIu3DS3dfd1NCVk5tZnM/view?usp=sharing

Its looks stunning on a 1080p display (thru VLC) and when I play it on a Seiki 4K monitor it looks the same, maybe a little bit worse. Could be the quality of the Seiki monitor though but the 4K video stream looks identical on the 1080p Samsung.

Edit: Don't watch it thru the youtube player, download it and watch in VLC or another video player. The video quality is amazing.

That's not surprising. Most 1080P video is mastered in 4:2:0 chroma, so a 4K video at 4:2:0 essentially is full 4:4:4 chroma when downscaled back to 1080P.

 

[NoOther]

I can understand that but why does 4K video look 4 times sharper than 1080p video on a 1080p monitor?

I am seeing a huge difference watching that above clip in 4K compared to 1080p on my Samsung monitor.

Is VLC making the video stream look 4 times better?

First, you aren't getting extra quality. Second, saying it 'looks 4 times better' is subjective.

What you are experiencing is a picture that is more dense and so you are less likely to catch the subtle differences you can pick up in a pixel to pixel composition. This is why occasionally images will look better at lower resolutions than their native resolution. However the quality is much higher on a 4k screen. Also not all 4k videos are actually filmed or created at 4k quality, there may be some filler in there which again is why it would look better at a lower resolution.

 

[MaZa]

The 4K video may be mastered better but also when you downscale a 4K image to 1080P with filters (even bilinear works, though there are better. Check out MPC-HC with MadVR) you get antialiased picture. It can dig out details which are simply simply missing in 1080P source (see DSR and VSR tests for samples) because the details that get shrinked away from downscaling are smoothed/blurred out instead of crudely cut away (this is something nearest neighbor filter would do).