issue with makeMKV files transcoding

[talbotron22]

I have been making my own internal media library using makeMKV and I would like to view the resulting video files without transcoding them further. I'm OK keeping them at the giant size right off the disk and will get a big external HDD if necessary. From a recent DVD backup I got a .mkv video file with the video codec:

H.264, 30FPF video
AC3 5.1 48000Hz
codec: mpge2video

The file is ~1.4gb for 30min video. They look flawless when played directly on the host computer, of course. However when I load into Jellyfin and watch from elsewhere, it is noticeably crappy. The video is blocky and jumpy. When I go into the Jellyfin info, it says that the stream is being transcoded due to "VideoCocecNotSupported". See picture below.

The player is a model 4802x Roku Ultra running Roku version 14.5. A quick googling shows this is the current Roku model that has been around for ~3 years. Any idea why the video stream is getting transcoded and looks bad? Is it a hardware or software thing? FWIW I had similar error messages and playback issues when I gave Plex a swing. Any help would be appreciated.

   

Thanks!

[RostigerSpieler]

So I would assume that pure MKV files require more performance and bandwidth than small MP4 files, for example, for streaming.

However, it may also be that you have activated the wrong transcoding settings in the Jellyfin settings.

For example, I have an AMD processor in my mini system and therefore use the following settings for transcoding:

Video Acceleration (VAAPI)

I have activated:

H264, MPEG2, VC1, and VP9

And hardware encoding is activated. Everything else is set to default.

I don't know how powerful a Roku device is, but maybe hardware encoding is too much for MKV files?

Try converting the videos to MP4 as a test. Preferably in H265 instead of H264, which saves storage space. If it then runs smoothly, you have found the error.

Of course, this is just a guess. But I know from my system that MKV files use a lot of bandwidth on my network, depending on the file size, which is why I convert all my films.

[alleycat]

The file is ~1.4gb for 30min video. They look flawless when played directly on the host computer, of course. However when I load into Jellyfin and watch from elsewhere, it is noticeably crappy. The video is blocky and jumpy. When I go into the Jellyfin info, it says that the stream is being transcoded due to "VideoCocecNotSupported". 

What are the specs for your server? What version of the Jellyfin server, 10.10.7?
Latest version of the Roku app?
Can you logon to your Jellyfin server with a browser (edge, chrome, firefox) or with the Jellyfin Media Player? And how does the video look there?

[34626]

Welcome aboard :-)
I dont have a solution for the exact problem, but i use Raspberry pi 4 with a USB SSD and LibreELEC + JellyCon - It has dirct playback.
You could consider a Raspberry pi 5, since its better, but i can play my 576p, 1080p and 2160p MKV movies and tv series.

[dthree]

This is likely a MPEG2 file ripped from a DVD, as you mentioned. Roku can direct play without transcoding with the following setting enabled.
Check the app settings for "Video codec support" -> "Support Direct Play of MPEG-2 content"
With this off, it will transcode DVD ripped MPEG2 files. Enable it and it will direct play. The bandwidth is higher, so this is not likely to work well remotely, only on LAN.