4.6.4.0: trouble hardware transcoding some VC-1 files

[rexerm 36]

Some -- but not all -- video files with VC-1 streams seem to cause transcoding to crash if I have hardware acceleration turned on.  You can see in the attached log that even writing to the log stops mid-sentence.  On the dashboard, I will see what's pictured in screenshot below. In Task Manager, I see that it will consecutively spawn 3 ffmpeg processes. Eventually, Emby will give up and report a "No compatible streams available" error.  However, the 3 ffmpeg process will remain.  Even if I reboot Emby, they remain and need to be manually ended (or the server completely rebooted).  If I don't do this and continue to play affected VC-1 videos, it will continue to spawn these processes and eventually eat up 100% of the CPU.

No GPU installed, just a Intel UHD Graphics 630, so I'm wondering if that is the main problem. My solution is to turn off HA for VC-1 codecs in the advanced transcoding menu, which seems to completely fix the issue.  Running a test right now to see if the slowdown from turning this off with affect a longer movie.

I'm not sure if this affected prior versions, as I never played these particular files until recently. Files were ripped from my own blu-ray and are in a standard MKV container.

ffmpeg-transcode-04e67547-4a6c-43f8-bef5-1aa1ae26ef97_1.txt

[Luke 42078]

Hi, as a test, if you disable hardware transcoding in server transcoding settings, how does that compare?

[rexerm 36]

8 minutes ago, Luke said:

Hi, as a test, if you disable hardware transcoding in server transcoding settings, how does that compare?

Yes, if I uncheck all of the VC-1 codec settings in the advanced hardware transcoding page, Emby can play those files perfectly.

Edit: as an aside, I was very happy to see this setting page be so granular! Allowed me to keep the fast HW transcoding settings turned on for the other codecs.

Edited July 22, 2021 by rexerm

[Luke 42078]

Hi, we're looking into this. Thanks.

[Guest]

Moved this post to Linux subforum

Edited July 24, 2021 by battkajs

[softworkz 5066]

@rexerm I'm not sure whether you would be willing to try a beta version of Emby Server. The issue with the zombie ffmpeg processes should be fixed meanwhile.

For the VC1 w. QSV crash itself, would you be able to provide a sample file for testing?
(privately via PM if you wish)

[softworkz 5066]

@rexerm - Thanks a lot for the test file.

I can confirm the crash with QuickSync HW decoding. It doesn't happen with sw decoding neither with Nvidia decoding.
We can submit this as a bug to Intel and hope that they might eventually fix it in their drivers.

At the side of Emby, your options are as follows:

• Emby Release (4.6.x)
  You need to disable all Intel VC-1 decoding options (like you already did)
• Emby Beta (4.7.x)
  No need to do the above, because automatic fallback to software-transcoding is working properly and those ffmpeg zombie processes are no longer being created
  It's still advisable though, to disable Intel-VC1 decoding because this will allow you to still have hw accelerated en-coding and just the VC1 de-coding will be done in software/cpu.

 

[rexerm 36]

Thank you so much! You guys are the best!