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Jerky playback with lost frames

Posted: 10 Mar 2022 18:36
by awik
Hi all,

I'm using Linux Mint 19.3 (Tricia) with Cinnamon. My VLC version is 3.0.8. The CPU is Intel Core i7-2720QM Quad Core. The graphics is Intel integrated i915.

My problem is jerky playback. The statistics reports lost frames. The CPU is more than 50% idle.

Anything that can be done to mitigate the problem, or at least diagnose it?

Regards,
Albert Wik.

Re: Jerky playback with lost frames

Posted: 23 Mar 2022 19:18
by awik
The jerkiness stops if I shut down the very graphics-intensive Second Life viewer Firestorm. Can applications compete for "GPU time" like they compete for CPU time?

-aw

Re: Jerky playback with lost frames

Posted: 24 Mar 2022 07:54
by RĂ©mi Denis-Courmont
GPU resources are not infinite. I'm sure what answer you expect here.

Re: Jerky playback with lost frames

Posted: 24 Mar 2022 09:07
by elitedata
The graphics is Intel integrated i915.
there is your answer.
integrated graphics share CPU/MEM recources.

Re: Jerky playback with lost frames

Posted: 24 Mar 2022 16:49
by awik
The graphics is Intel integrated i915.
there is your answer.
integrated graphics share CPU/MEM recources.
But there seem to be enough CPU/MEM resources, and I've tried adjusting process priority. So I'm thinking the contention is for some other, graphics-related, resource.

-aw

Re: Jerky playback with lost frames

Posted: 24 Mar 2022 16:53
by awik
GPU resources are not infinite. I'm sure what answer you expect here.
Yes. Maybe Linux/X11 does not implement any kind of "fair" scheduling of GPU resources, so that any process is "free" to hog and starve other processes for resources?

How can I find out if the problem is (a) decoding the video in time or (b) displaying the decoded frames in time?

-aw

Re: Jerky playback with lost frames

Posted: 24 Mar 2022 17:13
by elitedata
GPU resources are not infinite. I'm sure what answer you expect here.
Yes. Maybe Linux/X11 does not implement any kind of "fair" scheduling of GPU resources, so that any process is "free" to hog and starve other processes for resources?

How can I find out if the problem is (a) decoding the video in time or (b) displaying the decoded frames in time?

-aw
its likely that SL and VLC are using the integrated GPU to decode frames at the same time and its likely too much for the GPU to handle.
im not familiar with Linux but your problem sounds all too familiar to me.
i would think though, if you minimize SL (Firestorm), GPU use should cease from it and then VLC should work, but i dont know the implementation of firestorm on Linux though i am familiar with SL and firestorm (im an SL member for almost 20 years now)

Re: Jerky playback with lost frames

Posted: 24 Mar 2022 19:12
by awik
its likely that SL and VLC are using the integrated GPU to decode frames at the same time and its likely too much for the GPU to handle.
In fact, SL on its own is too much for the GPU. I'm getting less than 10 fps and it's jerky. Often it freezes for several seconds at a time.

I had an AMD FirePro, but it developed a memory defect, making the system crash, thus forcing me to pull out the card. Now, I'm considering getting a new graphics card, but it's a laptop and I'm not familiar with the compatibility issues. Is there a good place, like a forum, to go for assistance?
im not familiar with Linux but your problem sounds all too familiar to me.
i would think though, if you minimize SL (Firestorm), GPU use should cease from it and then VLC should work, but i dont know the implementation of firestorm on Linux though i am familiar with SL and firestorm (im an SL member for almost 20 years now)
I'm going to try the minimisation at some point.

-aw

Re: Jerky playback with lost frames

Posted: 24 Mar 2022 19:23
by elitedata
i do know that SL is very CPU & GPU intensive (memory, network and file cache also) but you can configure it to be balanced between both CPU & GPU as well as configuring Firestorm for a shorter drawing distance (drawing more objects on the display requires more CPU & GPU resources) and that may help reduce resource usage enough to balance what is available for VLC to operate but in your case, its probably unlikely to help much at all depending on the content you are playing in VLC, especially if its high resolution content displayed full screen.

Re: Jerky playback with lost frames

Posted: 02 Jun 2022 17:15
by awik
I tried minimising Firestorm, but it did not help.

-aw