TL;DR: I have HEVC encoded videos with an m4v extension (mp4 container), but Plex still is trying to transcode. How can I get it to direct play as the encoded video works on all devices?
So, I understand it’s possible to direct play HEVC files provided they are in mp4 containers. So this now brings me here since I cannot figure out why the Transcoder is kicking in. I have a NAS box running NAS4Free w/Plex. I am using the latest version of Plex on my box, and since it’s primary function is to be a dedicated storage system which can be accessed over the net, I did not put a high end CPU in there, i.e. I’m using a Celeron CPU @ 2.9GHz. I really do get that some files need transcoding when you throw and a mix of different file types, but I have come to be really nit-picky about that and have optimized all of my files to use web-optimized HEVC. I tuned my encoder’s settings to basically let the file be compatible with just about everything, at least in my house-hold.
So all of my files are encoded with this settings, making them really fast to buffer when being streamed on regular devices, and my 4K videos stream without issue over the net as well. However Plex is trying to transcode all of them, including my 4K videos, back to H264 based on the logs and then stream them. Not only is it now killing my CPU, but it’s using more bandwidth to stream the same video as it’s HEVC counterpart. This often results in the stream hanging, even on my home network. Naturally since my devices can all play HEVC without issue, I would want Plex to direct play the file instead of trying to transcode them. All my files are saved as m4v files which is an mp4 container. Any advice would be appreciated. 
