That is a separate issue related to the iHD driver that is used for Linux systems, which Synology’s OS is a modified version of. I recommend running a diversion on your iHD driver file to “set it aside”, which causes Plex to fallback to another driver file in the same folder the iHD resides.
You may need to modify the above path slightly if the driver is located in a different folder on Synology PMS installs. I believe it is. Run the command from the root folder after finding out for sure what path to use.
@bgrngod thanks, but that’s a separate issue I am already working around. The symptoms of that are far more severe than what I described above and effect all hardware transcoding.
The issue I’m referring to here is specifically with poor quality output when hardware transcoding 1080p HEVC to 720p. Switching to software transcoding the same thing and the quality appears fine. It also outputs fine when hardware transcoding from 1080p HEVC to 1080p and 1080p h264 to 720p.
You’ve already done an iHD driver workaround on the Synology 920+ and are seeing artifacting issues? My understanding of the issue discussed in this thread is that it’s very specific to Windows PMS installs. Maybe that’s not the case, but it seems to be based on what people have said and I took a shot at replicating myself. It only showed up on a Windows PMS install I setup.
What method did you use to workaround the iHD driver problem? Does it “stick” through PMS updates? The diversion method does, but some other recommends for handling it do not. Is there any chance it came back on your system?
Apologies for the delays in tracking this down, and thanks for all the diagnostics that have been provided here. We have a fix tested, which should be available in an upcoming PMS release.
In the interim, I’ll be providing an alpha build that has the fix applied. This build is only available for Windows, as that’s the only platform affected by this issue: Plex Media Server 1.20.2.3277-b2d16b7ca (Windows x86).
The usual warnings about alpha builds apply; this is going out without the usual full battery of testing, so please be prepared to downgrade to the existing public builds in the unlikely event that you run into any issues. Thanks for your understanding.
Yeah when I first got the DS920+ I SSHd in after each PMS update and deleted the iHD driver, but more recently I followed ChuckPa’s advice to edit the preferences.XML here Migration Issue? 4k not working well on DS920+ and that seems to persist across updates.
It is pretty evident when it uses the iHD driver though, as hardware transcoding basically doesn’t work, or rather it tries to but still smashes the CPU and causes the output to hang after a couple of seconds… Literally software transcoding works better than the DS920+ with the iHD driver in play.
The issue I described above with artifacts is far less of a big deal than that, but sounded similar to what was being discussed in this thread so I thought I’d ask. Now it has been confirmed this is a Windows only issue I’ll try to grab some examples and start my own thread regarding my issues.
EDIT: Here’s a link to my issue Poor image quality when HW Transcoding HEVC 1080p content to 720p Obviously the output is nowhere near as bad as the pixelation examples in this thread, but the colour bleed/streaks can be quite noticeable when compared to all the other output.
@Ridley Can confirm also just rolled out the Alpha and re-enabled HW Transcoding and tested. Used same source content as before. This time, no pixelation or quality issues in the brief test I did. I also confirmed in task manager it was using the iGPU and not CPU. Fix appears successful.
nuc7i5bnh
After a simple test, the picture quality of this version of hardware transcoding is equivalent to 95-99% of the hardware transcoding quality of version 1.17. Very few videos have subtle patches visible to the naked eye. after such a long wait, at least I can accept this.
Thanks to the developers for solving this problem, we can finally say goodbye to the 1.17 server side.
Lol, was this being worked on for the ~year it was a bug? Cause the day after @elan pinged it to the other engineers it was fixed. Jokes aside, thank you!
@elan kind of off topic, but are applications expected to open up for interns for next summer/spring? I’d like to get in on that work that needs scheduling
The new alpha build seems to be working much better than before. I can see improvement in the movies, but there are still intermittent choppiness. Unfortunately, even with the improvement, it still seems like JellyFin’s hardware acceleration is churning out much cleaner quality without sacrificing much more.
I haven’t run into any choppiness that @T_Le was running into. The only “problem” that I can see so far is SOME of the blockiness when going into low bitrate 480p. It’s only a little worse at those levels compared to software transcoding, but I don’t need transcode anything lower than 720p 4mbps for one of my family members so it’s a great fix. I’m also not having any stability issues in the alpha build. Thanks @elan
Oh I see. It seems like the quality seems much better when allowing bitrate to 720p 4mbps. I usually go for 720p 3mbps due to my limited upload speed and I am seeing the problem with this bitrate or lower.
