During a running mp4 video, mpv and vlc loose video frames when switching to another workscreen in Compiz and output stuttering scaled videos
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
mpv (Ubuntu) |
New
|
Low
|
Unassigned | ||
vlc (Ubuntu) |
New
|
Low
|
Unassigned |
Bug Description
When I check hardware acceleration in vlc for intel graphics drivers using intel-gpu-tools, it seems like vlc has a problem with the 3d render engine in the vaapi module.
I use Ubuntu MATE 20.04 with Compiz as a window manager (used plugins Scale, Expo, Desktop Wall, etc.). When I work with several virtual desktops, the load on the 3D rendering engine of the Intel driver drops when I switch to a different desktop than the one on which vlc is active.
In the Scale plug-in (overview of all windows on all workspaces) the graphics output then stutters in the reduced video image from vlc. In a normal HD video (1280x720) the load drops from approx. 32% to approx. 8%. The video engine (hardware acceleration) has no errors.
Occupancy continuously at 4% to 6%.
Vlc works perfectly under Nvidia graphics (no stuttering graphic image in the reduced vlc video window with an overview of all windows on all workspaces).
Gstreamer (Ver. 1.18) works fine with gst-play-1.0 on vaapi and nvidia-vdpau. There is no drop in the utilization of the 3D rendering engine with an overview of all windows on all workspaces in the Scale plug-in. (Checked with intel_gpu_top at Intelgraphics).
The graphics output runs without stuttering in the reduced vlc window and the Utilization in 3D Render Engine is continuously around 33% throughout.
This issue exist already a long time before up to now and in other distros and flavors with Compiz.
snapshot from intel_gpu_top with gst-play-1.0
Render/3D/0 Engine is continously used when switching to different workspaces from active vs.
Scaled video window shows normal (fluently) scaled video in overview of all windows of all workspaces.
intel-gpu-top - 208/ 208 MHz; 35% RC6; 0.86 Watts; 137 irqs/s
IMC reads: 0 MiB/s
IMC writes: 677 MiB/s
ENGINE BUSY MI_SEMA MI_WAIT
Render/3D/0 37.98% |█████████████▎ | 0% 0%
Blitter/0 0.00% | | 0% 0%
Video/0 13.00% |████▌ | 0% 0%
VideoEnhance/0 0.00% | | 0% 0%
snapshot from intel_gpu_top with vlc
Render/3D/0 Engine breaks down when switched from active workspace to another workspace where vlc is not active.
scaled video is stuttering when all windows of all workspaces are shown in overview!
intel-gpu-top - 420/ 421 MHz; 48% RC6; 0.47 Watts; 50 irqs/s
IMC reads: 0 MiB/s
IMC writes: 201 MiB/s
ENGINE BUSY MI_SEMA MI_WAIT
Render/3D/0 3.00% |█ | 0% 0%
Blitter/0 0.00% | | 0% 0%
Video/0 6.49% |██▎ | 0% 0%
VideoEnhance/0 0.00% | | 0% 0%
^C
snapshots not at the exactly same position in the video!
My machine:
tux@tux-
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description: | updated |
Sorry I don't see the problem. Can you state concisely what you think the issue is?