Let me try to clarify some more. When playing a video, not with Plex, such as from another DLNA server or from the USB drive, the software you are using is Panasonic’s video player. This is the code they wrote to play videos. The OS they run, some version of Opera, also has code to play videos. The OS is limited and can only support specific codecs. Panasonic’s code bypasses the OS code and handles everything within it’s own code. This allows that code to support additional codecs that the OS cannot. The Plex app does not have it’s own code to play video. It uses the code from the OS, which is why codec support is hardware dependent. We can’t use Panasonic’s code to give us the same abilities.
Think of the Windows OS and their built in photo viewer. It can view bmp, jpg, gif and a few others. But it can’t view pdf or Apple’s new aiff format or any type of video files. A program dependent on the OS would be limited to the same things. Notice that Windows file explorer which works at the OS level can generate preview icons for these formats, but not others. This is Plex. Put if you have PhotoShop, you can see in it’s UI, previews for almost any format. This is the Panasonic player.
The solution would be for Plex to write a native player app. This may happen in the future, but it’s not easy. Plex did do this with PMP and Android, where we now have our own player so we can support more codecs that the device itself does not natively. Starting to appear on Apple now too.
For you, this is a newer UHD TV, which does support HEVC. Our older app isn’t able to detect hevc support, which is why you still can’t play HEVC even though it is technically supported. You will need to wait for our new app which can detect hevc support. It is just a matter of time before the v2 app makes it to Panasonic.
This is something that could happen. We did this for LG where we allowed users to opt into the new app. We still need to go through internal testing before releasing anything, even for Beta. We’re just not there yet for Panasonic.