Up until this latest version HW Transcoding was working fine. In 1.21.3.4021 my Synology 6 is no longer using HW transcoding and CPU is spiking to 100%. I have disabled the Enable HDR tone mapping as some have suggested but that made no difference.
Previously I was able to use HW transcoding to play my MKV videos and not they are unwatchable due to buffering.
Server Version#: 1.21.3.4021 ← Plex native app for synology not the Docker app
I have been using Plex on this Synology for several years and HW transcoding WAS working until this version. The same file that played fine a week ago now buffers as CPU is maxed in this latest version.
So why does this latest version not find the transcoder anymore when it did in the past?
The 8am video was a badly encoded file, that is not the file in question. The file in question was included in the XML. It should have been played closer to 9am.
And I am telling you that in the previous PMS build: PlexMediaServer-1.21.2.3943-a91458577-x86_64
Files that are HEVC encoded were able to be transcoded in real time with no buffering. Now this PMS version it can not do the real-time transcoding.
This Synology does have HW transcoding (or at least it did have it supported before). If that changed and is no longer supported my apologies, but all I can say is that a previous show that transcoded in real time in the previous PMS no longer does in this version.
I have the video xml from that same video attached in this ticket along with new logs. Started ~ 10:15am.
Feb 16, 2021 06:45:44.005 [0x7f1038c42700] INFO - Plex Media Server v1.21.3.4021-5a0a3e4b2 - Synology DS1815+ x86_64 - build: linux-x86_64 synology - GMT -06:00
Feb 16, 2021 06:45:44.005 [0x7f1038c42700] INFO - Linux version: DSM 6.2.3.25426-3, language: en-US
Feb 16, 2021 06:45:44.005 [0x7f1038c42700] INFO - Processor Intel(R) Atom™ CPU C2538 @ 2.40GHz
Ignore the HW transcoding then. The question then is WHY in this latest PMS did trancoding in general become more CPU intensive then with HEVC videos? In the previous PMS my lowly atom processor was able to do real time transcoding, and now it can not. That was the details I gave in the previous post.
These 6 videos will allow definitive profiling of what the C2538 is capable of
Feel free to download a really nice one and play directly on your computer to use as the “standard”
Using DEBUG logging on, VERBOSE logging off,
All 7 test files can be played with everything captured in a single log ZIP file set.
(Videos are 1 minute length)
Those all played with no lag, but maybe due to the short length.
So these logs showed all of those playing, I did not play the 20 mbs h264 since I know that works fine as it does not need to be transcoded.
I lastly played the second video xml I uploaded previously. This is a HEVC video that played fine in the previous PMS release with out skips, yet in this PMS release with the HDR tone disabled it only makes it about 15 seconds before needing to rebuffer.Plex Media Server Logs_2021-02-16_13-32-07.zip (5.3 MB)
The point of me giving you these files and pointing out the site was so you have known-good test files and can help educate me what you expect from the DS1815+
I have (here in my office),
DS1815+
DS418J
TS-128A
TVS-1282
TN-2850
in addtion to my workstation and NUC i3 (kabylake)
What I expect is a show that worked with no buffering issues while being transcoded in the previous builds continue to work with no CPU stuttering/rebuffers in the future. That does not seem to be the case as the new PMS changed how HVEC files are being handled.
Even turning off the new “feature” keeps the transcoding of HVEC files as a higher CPU load than whatever was done previously. So the previous build:PlexMediaServer-1.21.2.3943-a91458577-x86_64
Was able to transcode better than realtime
Format profile : Main 10@L4@Main
Codec ID : V_MPEGH/ISO/HEVC
Bit rate : 3 460 kb/s
Frame rate : 23.976
And now it does not. So I guess that is my expectation, HEVC 1080p transcoded in better than real time like the previous builds did.
So if there is a dev of PMS to read this comment that something in the transcoding of HEVC was made slower in this most recent build.
