Vlc player misbehaves

[haha]

After this update, VLC media player is having trouble showing scaled video in fullscreen. The bottom 200 rows of the video are cut off and only the top part is shown, scaled to the screen. The video plays properly in windowed mode; only the fullscreen mode is affected when the video needs to be scaled to fit the screen.

My system is on XFCE, if that helps. The screen resolution is 1920x1080.

What settings should I examine and change to fix this problem?

[Eruantien]

VLC seems to be working well on my end. Did you try with different video formats and maybe tweaking the Hardware-accelerated decoder option? In rare occasions I gotta disable it, but for the most part works well with VDPAU Video Decoder option enabled

[haha]

Hardware acceleration was disabled before. I tried setting it to VDPAU based on your idea, but it breaks in a different way:

VLC media player 3.0.21 Vetinari (revision 3.0.21-0-gdd8bfdbabe8)
[000055b6abc815a0] main libvlc: Running vlc with the default interface. Use 'cvlc' to use vlc without interface.
[00007f902cc0f140] avcodec decoder: Using G3DVL VDPAU Driver Shared Library version 1.0 for hardware decoding
[00007f902cc0f140] main decoder error: buffer deadlock prevented
[00007f902cc0f140] main decoder error: buffer deadlock prevented
[00007f902cc0f140] main decoder error: buffer deadlock prevented

and no video plays at all (just a fully black screen in both windowed and fullscreen modes).

Another failure mode with VDPAU:

VLC media player 3.0.21 Vetinari (revision 3.0.21-0-gdd8bfdbabe8)
[000056416453f5a0] main libvlc: Running vlc with the default interface. Use 'cvlc' to use vlc without interface.
[00007ff698c0ba40] avcodec decoder: Using G3DVL VDPAU Driver Shared Library version 1.0 for hardware decoding
nouveau: kernel rejected pushbuf: No such device
nouveau: ch5: krec 0 pushes 1 bufs 3 relocs 0
nouveau: ch5: buf 00000000 00000045 00000004 00000004 00000000 0x7ff694006000 0x252000 0x8000
nouveau: ch5: buf 00000001 00000054 00000002 00000002 00000000 0x7ff619500000 0x2fa0000 0x100000
nouveau: ch5: buf 00000002 00000056 00000002 00000000 00000002 (nil) 0x34a0000 0x400000
nouveau: ch5: psh 00000000 0000000058 000000009c
nouveau: 	0x200541c0
nouveau: 	0x00020013
nouveau: 	0x0002fa01
nouveau: 	0x0002fa07
nouveau: 	0x0002fa05
nouveau: 	0x00000003
nouveau: 	0x20084100
nouveau: 	0x0002fa00
nouveau: 	0x00034a00
nouveau: 	0x00000200
nouveau: 	0x00034af2
nouveau: 	0x003f0e00
nouveau: 	0x00034a02
nouveau: 	0x0000f000
nouveau: 	0x00000000
nouveau: 	0x200140c0
nouveau: 	0x00000000
nouveau: kernel rejected pushbuf: Invalid argument
nouveau: ch6: krec 0 pushes 1 bufs 0 relocs 0

at which point I had to force-quit the VLC window, which wasn’t responding nor showing video.

Going back to “Disable” for hardware acceleration, at least the video plays.

I attach two pictures here which show the problem with full-screen fit-to-screen.

First is VLC in Windowed mode. The “Handforth PC Clerk” text at the bottom of the frame is rendered fully.

Next is VLC in Fullscreen mode, with the “Always Fit Window” option true. The “Handforth PC Clerk” text is cut in half, and the bottom several rows of the frame are missing.

Disabling “Always Fit Window” is a workaround for videos smaller than the screen size, but does not help for larger videos.

[haha]

I solved it on my system, at least until the next breakage. In VLC preferences → Video → Output, change “Automatic” to “X11 video output (XCB)”. The problem was 100% repeatable with “OpenGL video output” and does not occur with “X11 video output (XCB)”. Most of the other options, including VDPAU and framebuffer, lead to no video or rapidly flickering video.