First I’d like to define some terms and provide a bit of recent history to get everyone on the same page:
TV UI - This is the 10 foot interface in PMP intended to be navigated via the minimal command set (up/down/left/right/enter/back)
Desktop UI - This is the interface present in PMP and Plex for Mac/Windows which is akin to the Web interface
PMPv2 - Plex Media Player (PMP) version 2.x and the currently released version on https://www.plex.tv/media-server-downloads/
PMPv3 - Released as a forum preview and was essentially PMPv2 but with newer dependencies (Qt, FFmpeg/MPV, etc).
Plex for Mac/Windows - Similar to PMP when in the Desktop interface using MPV as the playback engine. For simplicity I’ll call this the “Desktop App” from this point on.
LibreELEC - Forked from OpenELEC which stands for Open Embedded Linux Entertainment Center. This is the Linux-based OS that runs PMP and does very little else.
PMP has both the TV UI and the Desktop UI. This two-mode aspect of PMP has been a little awkward from the beginning. The two modes have very different use cases and it’s not common to be actively switching back and forth between the two modes. Additionally, the TV mode was less discoverable when starting the app in the Desktop UI. Due to architectural reasons, it became difficult to keep updating the Desktop UI in PMP and so we encourage users of the Desktop UI to use the Desktop App instead of PMP. Eventually we intend PMP to have just the TV UI and the Desktop App have just the Desktop UI. This eliminates the confusion of the two UIs serving completely different use cases in the same app as well as potentially exposing the TV UI to users who were unaware of its existence by exposing the separate download.
We promised to keep PMP working and fix serious issues with it. To that end we merged a user-submitted PR to fix PMP for MPV 0.33 a few days ago and then very shortly afterwards made another commit that fixed where this commit broke vaapi-egl playback. It’s worth noting that PMPv2 does still function as before and still works with current media servers.
We also promised to “actively [investigate] the best way to continue supporting HTPCs as a platform.” The eagle-eyed among you may have noticed that the Desktop App recently gained support for reading an mpv.conf file (Plex for Mac and Windows). This is but the first in a line of updates coming which will bring features over from PMPv2 into the Desktop App.
We did a forum preview of PMPv3 which was essentially PMPv2 but with newer dependencies (Qt, FFmpeg/MPV, etc). This was not built for Linux because there is little need there since Linux users are building from source anyway and can update these dependencies themselves as they see fit. This work has been paused in favor of other high priority tasks such as modernizing our build infrastructure and media server support for Apple’s M1 processor.
The LibreELEC (LE) version of PMP has always been a pain to build. LE is designed around building Kodi and is not really a general purpose OS beyond that. It expects several OS-level configurations to be made through the application (Kodi) and substituting a different UI application here (such as PMP) requires that the application provide the UI for these changes. Those of you who have paired a bluetooth device or configured LIRC in LE know that this is far from a good user experience. As such, we’ve decided that we will no longer continue working on a LibreELEC version of PMP. We encourage users of LE to switch to a full Linux distribution with PMP as an app that runs there. I personally used to run LE but found it painful to do too many things and so I switched to running a full distro (Ubuntu) and running PMP as an app on top of it (my notes on setup are here for those interested: https://www.cod3r.com/2019/11/plex-media-player-appliance-using-ubuntu/).
We are actively investigating releasing a Linux version of the Desktop App however in the fractured landscape that is the large set of Linux distributions, packaging is an issue. It is even more of an issue for an application that has a UI than it is for a headless application like Plex Media Server. We will be investigating whether a snap package will meet the needs for packaging the Desktop App for Linux.
There is a new PMP coming (tentatively codenamed PMPv4) which is based on the work in the Desktop App. This will contain a new version of the TV UI only (no Desktop UI) which is the same UI that we have been updating on some smart TVs and game consoles. It is based on a new architecture and is actively developed.
HDR support is entirely dependent on the underlying OS support for outputting it but this is likely not going to be the HDR you think it is. MPV has taken the stance that they will do tone-mapping from the source to the display. This doesn’t mean it only uses tone-mapping to go to SDR; it’ll map from HDR to HDR as defined by its configuration (https://mpv.io/manual/master/). So this means that Dolby Vision will end up being tone-mapped to the output color space and you are not going to see Dolby Vision logo on your TV. In theory, this could yield the same results in terms of what is actually displayed. In many ways this is akin to audio passthrough vs the device decoding to PCM, or at least it was before Atmos/DTS:X came on the scene.
Hopefully this helps answer questions you have had in this thread. I had intended to post this reply earlier but it took a while to figure out within the company which parts we wanted to mention here.
