www.makemkv.com

Apologies if this has been previously covered in another thread. I have been searching but not had any luck finding anything on the board.

I have been converting my 4k collection via MakeMKV and storing on a Synology media server. I use the Plex app on my LG OLED television for playback and, for the most part, the results have been stellar. However, a few of the files will start out playing fine and then suddenly the picture reduces to a small square in the upper left hand corner of the screen that is distorted. Later in the program the picture will return to normal, only to happen again later. Examples of films this occurs on (and always at the same locations) include Psycho, Backdraft, The Goonies and Dunkirk. The same files play fine on my laptop using Plex or VLC.

Additionally, I have one file, Perdita Durango, that exhibits a full-screen display of psychedelic colors. I can get it to display the correct picture if I change the video quality setting to 1080.

Any help with this will be greatly appreciated.

I'm no expert, but I have been using MakeMKV to rip my personal collection of movies and TV shows for several years now, and I serve these to our home with a PLEX server. I have come across similar issues where some movies just didn't play properly on a specific device. They would play well directly on the server either through PLEX or VLC. This tells me straight away that the issue does not lie with the ripped file itself.

Where I have found problems is with the bandwidth between the streaming device and the server. Particularly if you are streaming 4K at high bitrates, you need to have a solid and stable network connection. For better or worse, what I've found is that there is a setting (at least on PLEX on the nVidia Shield PRO) that will ask for a transcoded lower bitrate if there are any potential bandwidth issues. This was causing terrible problems until I worked out how to turn it off. It sounds like this might be similar to your issue? I could imagine that the client requests a lower resolution stream due to bandwidth limitations, and then fails to display this at the full dimensions of the screen -- thus giving the impression of a small picture in the corner. When bandwidth recovers, the full resolution is transmitted again.

Anyway, just sharing some thoughts. Sorry I can't help further.

Plex calls this Direct Play or Direct Stream.

if Plex is trying to transcode a file, that might explain the weirdness you're seeing. The Dashboard in Plex will help you know what's going on.

Streaming 4K requires a lot of bandwidth. if your Plex server is on wifi and your Plex client is on wifi, you might not have enough bandwidth as peterkirkham pointed out.