Bad/pixelated quality

[is77s7s]

I have tried messing with all kinds of settings for a while now, but it just seems that streaming with JellyFin makes the video pixelated no matter what settings I change. 

- On Plex, the video is directly streaming instead of transcoding so quality is original (I don't understand why JellyFin forces transcoding but whatever...)
- The transcoded output from JellyFin is always pixelated, which is not the case on Plex.
- Look at the embedded pictures for comparison

JellyFin:

Plex:


Settings:

[Efficient_Good_5784]

You will either have to look at your logs or playback info (during video playback) to figure out the reason Jellyfin transcodes the video.

It depends per client, but you either have a video file, audio file, or sub file that is incompatible with the client, forcing a transcode.

[TheDreadPirate]

Can you tell us what client you are using? Also, information about the video (codec, container). And your server specs.

Upload your jellyfin and ffmpeg logs to pastebin and link them here.

[is77s7s]

macOS Chrome and Safari tested. Here is the pastebin: https://pastebin.com/raw/dQY4J2g7

[TheDreadPirate]

Here's your problem

Code:

Stream #0:0 -> #0:0 (hevc (native) -> h264 (h264_nvenc))
  Stream #0:0: Video: h264 (Main), cuda(tv, bt709, progressive), 3840x2160 [SAR 1:1 DAR 16:9], q=2-31, 7076 kb/s, 23.98 fps, 90k tbn (default)

You're converting an already low-ish bit rate HEVC 4K video to H264. 7Mbps H264 is not enough bits for good 4K. Heck, 7Mbps HEVC 4K (the original bit rate and codec) isn't great either.

For reference, my 1080P HEVC files are ~10.5Mbps for the video stream.

[is77s7s]

I don't understand... you're telling me that my video file is too bad, meanwhile I can stream it on Plex without this horrible pixelation? Obviously they are both using the same video file...

[TheDreadPirate]

Your video is transcoding in jellyfin, but probably not in Plex. This is a client side issue since the client tells the server to transcode and how to transcode. You mentioned Chrome and Safari in MacOS. Have you tried Jellyfin Media Player? The standalone desktop app has better codec support than the Jellyfin web client. And it should play the video without transcoding.

https://github.com/jellyfin/jellyfin-med...r/releases
https://github.com/jellyfin/jellyfin-med...arized.dmg

[is77s7s]

Thanks for the recommendation. I've now disabled transcoding for all users, forcing myself and my friends to use Jellyfin Media Player and its so much nicer! Both much much faster and of course better quality as it direct plays everything. Should almost be a top-level banner on the website that the client provides a much better experience.

[olanwe]

There is also a bug in the Jellyfin server limiting the maximum transcoding bitrate to the original source-bitrate, so transcoding more efficient codecs into less efficient ones (like HEVC to H.264) will always result in worse quality (as H.264 requires more bandwidth for maintaining the same picture quality).
Jellyfin versions without this bug (up to 10.8.9) used a higher bandwidth in such cases.
This bug has already been fixed in the master, so it will be fixed in 10.9.
(See https://github.com/jellyfin/jellyfin/pull/9738 )