Freeze / hang when watching YouTube video in mpv [experimental backends] [glx]

[TRSx80]

Platform

GPU, drivers, and screen setup

Environment

Configuration:

Not much (if anything) of the above has changed since I put all of that same information back in this unrelated issue

picom version

$ picom --version

vgit-a8e8b

$ picom --diagnostics

[ 03/28/2020 01:12:21.305 get_cfg WARN ] --max-brightness requires the experimental glx backend. Falling back to 1.0
[ 03/28/2020 01:12:21.313 register_cm FATAL ERROR ] Another composite manager is already running

Steps of reproduction

This was the main reason I wanted to lodge this report. I have been trying different cases to see if I can reliably reproduce the problem. I figure I should start documenting them before I forget.

• Open certain (all?) YouTube video(s) in mpv (which uses youtube-dl).
  • In fairness, I only tried so far with 2 different videos. But so far they both do it. Not much of a sample size, I know...
  • These are the videos:
    • https://www.youtube.com/watch?v=do7Jl_4_d5w
      • This is the one I downloaded to SSD (see below)
    • https://www.youtube.com/watch?v=l9nh1l8ZIJQ
• Interestingly, when I download that first video with youtube-dl to my local SSD (which seems to go fine) and then play it using mpv, the problem still happens.
• Opening a regular movie that I had on disk in mpv and that works just fine. So maybe something is different in the video encoding? I can report details back of that video if you feel it's relevant.

Expected behavior

Video to play normally and not hang / freeze my system.

Current Behavior

Almost immediately my system freezes, I cannot do anything except move the mouse, cannot change windows, close anything, not even $mod+q which normally will close any window... I have to completely exit my session back out to lightdm login greeter screen.

Stack trace

Let me know if this will be needed... I am still having bad memories of the last time I had to dig into all this stuff. But I will try and contribute if it is really needed.

Other details

Disabling --experimental-backends makes the problem go away.

I had it enabled to try and help out and do my part, so I guess I found something. So what do I get? 😄 😄 😄

Happy Friday, man! 🍻

[yshui]

Thanks for testing the experimental backends! 👍

Can you attach the debug log file? And if you can, can you get a stack trace when picom freeze?

[sleeperzjf]

I have encountered the same problem, if I use mpv to watch a video, a few munites later my screen will freeze and I can do nothing, but the audio keeps going. I have to push down my power button to shut down my laptop.

[TRSx80]

Thanks for testing the experimental backends! +1

Can you attach the debug log file? And if you can, can you get a stack trace when picom freeze?

Sorry for bailing on you @yshui. I tried to do all that before but it took hours of my time trying to learn the tools. I am willing to try and help out, but I think it would be very helpful if there were maybe a link to some step by step instructions somewhere how to do this. I am sure I can't be the only one who feels the same way. I imagine it is beyond the average user to know how to use such debugging tools. I am still willing to help, up to a point. But when that point is taking too many hours away from other things, I am sorry but I guess I lost interest to continue at that point. 😞