Thanks for providing such a great app. Ive got a problem related to hardware acceleration on a Synology 920+. I hope this is the right place for such questions.
Playback is fine when hardware acceleration is turned off however CPU utilistion ranges from 30 - 100% . When I turn hardware acceleration on CPU utilisation drops to 20% but playback is extremely poor, jumps forward to random parts of the video and/or does not play at all. I’ve done some searching around and could not find an answer. I installed the latest 64bit version manually from the plex website.
Any ideas on what could be the source of my problem?
Server Version#: 1.19.4.2935
Player Version#: 4.30.2
That NAS does not seem to be very powerful. We are still evaluating it for our compatibility guide. I doubt it can transcode 4K well based on similar models but I don’t know what you are trying to play.
You seem to have turned on Verbose logging which is not useful as it makes the logs roll over too fast.
Noted. I have attached new logs with debug selected only. I am trying to play a 1080p file in the web player.
I see that compatibility is still being tested. Since everything runs perfectly fine with hardware acceleration off, I think I will turn it off for now and deactivate plex pass until compatibility is finalised.
Verbose still enabled. Make sure you change things in the server settings section, not the Plex web client settings section.
Jul 02, 2020 13:42:29.049 [0x7f7787159700] DEBUG - MDE: E1 - The List: no direct play video profile exists for http/mkv/hevc
Jul 02, 2020 13:42:29.049 [0x7f7787159700] DEBUG - MDE: E1 - The List: no direct play video profile exists for http/mkv/hevc/ac3
Transcoding for two reasons:
PC web browsers do not support HEVC video (Reference)
Chrome does not support AC3 audio (transcodes to AAC on my PC, haven’t tried other browsers).
Edit: Audio transcodes on the CPU, so not directly relevant to problems with hardware acceleration. Although on some clients, such as Smart TVs, transcoded audio + subtitles results in transcoded video.
Use Plex for Windows/Macintosh or Plex Media Player instead of a web browser. They do not have the limitations imposed by web browsers and will direct play most media. Available at plex.tv/download.
Ah! using the plex app fixed it! Can watch 4k video on the pc app and a 1080p video on my LG C9 tv at the same time with very little CPU usage. Thank you very much for your quick replies. Sorted out the verbose logging issue as well so i am in good stead for next time I need to ask for help.
You can watch 4K material on your C9. Just be aware of the Plex client & TV limitations:
To avoid video transcoding while watching 4K and HDR material:
Never choose image based subtitles.
If using text subtitles, never choose TrueHD audio.
A strong 5Ghz WiFi connection is sometimes preferable to a wired Ethernet connection.
Audio Details
With Plex app on LG:
Enabling image based subtitles, PGS & VOBSUB, forces a video transcode.
If the audio is transcoding, enabling text subtitles, SRT, also forces a video transcode.
The C9 direct plays AAC, AC3, EAC3, and dts audio with 5.1 or fewer channels. dts-HD MA audio also direct plays. TrueHD audio always transcodes.
So, to watch 4K and HDR material:
Never choose image based subtitles.
If using text subtitles, never choose TrueHD audio.
Network Details
The Ethernet port in the C9 is rated at 100 Mbps.
The WiFi radio in the C9 is capable of faster connections than 100 Mbps when using 802.11ac on 5GHz channels. I’ve never found exact technical specifications, but mine connects to my Asus router at 300+ Mbps.
Some 4K movies burst above 100 Mbps during playback. The value shown in Get Info is an average.
So, if a) you see buffering, b) the video is direct playing (Plex Dashboard), and c) the TV is on a wired Ethernet connection, try switching to WiFi.
