Pixelated Colors

[hdjv]

Hello,

I'm a newbie when it comes to high quality video playback, graphics settings and the like.
 
I'm just trying to figure out why there is pixelating and fuzziness occurring in the some of the color. It's a 4k MKV file (which is about as much as I know about the file), so I figured it should look a bit smoother.

Is there a setting I should tweak? Is the file just not great quality? 

Attached photos below.

Thanks in advance!

           

[bitmap]

What's your host OS for the server? Can you run mediainfo or ffprobe and provide the results here? Looking for codec, stream information, etc...

Also, logs from when you took that screenshot (or if you can recreate it) would be helpful. Generally what you're seeing is that something is either a) not the quality you think it is or b) it's not compatible with the client you're playing it on so it's being transcoded which is going to lower the quality, sometimes significantly.

[TheDreadPirate]

IMO, that looks like it is transcoding. Either to a really low bit rate or the GPU is older.

Your jellyfin log should contain a "TranscodeReason" field for the playback.

[nyanmisaka]

Looks like the macroblocks is caused by insufficient bitrate. Can you share the FFmpeg.Transcode*.log?

Also, what is your GPU model?

[hdjv]

Thanks for the replies, here's some more info.

The host OS is Windows 11.

Here is the media info for the file.

   

Here are the logs the appeared when watching back that scene.

           

GPU is a GTX 1660 Super. (I know, not an amazing card, but again I thought it should be good enough.)

As an experiment, I downloaded the 1080p version of the movie and the issue was still present, but at a much less extreme scale. Instead of giant blocks, the picture was just a little more noisy in those areas, which is what I would've expected.

Reference:
       

Thanks again for any help. I apologize for my lack of understanding.

[nyanmisaka]

The original bitrate 6387 kbps is too low for 4K video.

Please adjust the encoder preset to medium or even slow.

[hdjv]

Tested a couple of different encoding presets but they didn't seem to make a noticeable difference.

I just took this screenshot while the encoding preset was set to veryslow.

     

If you're saying the bitrate is too low for a 4k video, are you saying that the problem lies in the file? Is there a way to ensure you're getting a high bitrate, high resolution download? Or do people typically not upload movies in such a high quality to preserve storage space?

Thanks again.

[TheDreadPirate]

We generally don't talk about where we get our media. Wherever your are getting yours from used a really low bit rate for the video. 6387Kbps is appropriate for 1080P video but waaaaaay too low for 4K.

[hdjv]

Understood. What would be an acceptable bitrate for 4k?

[TheDreadPirate]

From my experience using HEVC, at least 15Mbps. Straight off a bluray, 4K is usually north of 40Mbps.