I think I may have found a bug that is causing choppy video playback in the Plex HTPC app. Living in the UK most of my media has been recorded at 25fps and plays back smoothly when the refresh rate of the PC system is set to 50 Hz. If any other refresh rate is set e.g. 60 Hz or 24 Hz (two common settings) there will be a slight or significant judder or choppiness when viewing the video. Setting the system to 50 Hz as default means I can play 25 fps video in any app smoothly. To play 24 fps video (usually films) I change the refresh rate of the system to 24 Hz with the same result. All good so far. Now some apps including Plex HTPC and Kodi (using the official Plex add-in) have an option to automatically change the refresh rate of the system depending on the frame rate of the media being played. The Kodi app using the official Plex add-in does this flawlessly making the whole experience swift and almost seamless moving from 60 Hz to 50 Hz to 24 Hz and back depending on the media fps then defaulting back to the system set 50Hz when closed.
Now here is the problem, Plex HTPC doesn’t appear to do this correctly when this option is selected. For 25 fps media it always sets the system to 60 Hz resulting in choppy video display. It works fine for 24 fps video such as film, automatically setting the system to 24 Hz but then always returning to 60 Hz instead of 50 Hz when attempting to play media recorded at 25 fps.
So it appears there may be a bug preventing correct setting of the 50 Hz refresh rate for 25 fps media when using the automatic option in Plex HTPC but not in Kodi. (I do realise that the automatic change option is a part of the Kodi app player and not the Plex add-in).
Could anyone see if they can reproduce this behaviour and if proven perhaps a fix could be provided for the next HTPC update if possible please? Many thanks.
Hi, I have uploaded the log file, I used a 24 fps video and a 25 fps video. The 24 fps video played fine as the system default of 50 Hz was changed to 23.976 Hz by Plex HTPC however the 25 fps video played choppy as the system default of 50 Hz refresh rate was changed to 60 Hz by Plex HTPC. Please let me know if you require more information. Many thanks.
Hi, thanks for your reply. The PC display settings (Settings->Display->Advanced display->Choose a refresh rate) changes to indicate the current display rate with each change initiated by Plex HTPC or Kodi. The rates shown to be available are as follows:
60 Hz (Interlaced)
60 Hz
59.94 Hz (Interlaced)
59.94 Hz
59.94 Hz (Interlaced)
59.94 Hz
50 Hz (Interlaced)
50 Hz
24 Hz
23.98 Hz
The DisplayPort output from the Nvidia Quadro P1000 is converted to HDMI via a passive adapter and fed into a Marantz AVR. The HDMI output from the AVR is fed into an HDMI splitter to feed a Samsung TV and a JCV projector.
Yes, I agree the available output options from the card does seem odd… I thought perhaps it is to do with the EDID from either the AVR or the splitter however even after removing these items from the chain and feeding the output from the card directly into the TV or projector it provides the same options and the same results.
The strange thing is that even with the limited available options the Kodi player determines the correct rate to choose every time… however, I much prefer to use the Plex HTPC interface.
Many thanks for your help with this.
