digital clock in systray won't be captured properly with compiz window manager in Ubuntu 20.04 Mate Desktop

[Atilla Karaca]

Summary of the bug: When I capture digital clock in the systray on Ubuntu 20.04 Mate Desktop, the video from the captured area looks erroneous, clock in the video sometimes repeats between a few seconds back and forth, sometimes it captures a still frame from the previous capture. It happens especially in the systray digital clock. When I capture the whole screen it records rest of the screen
but systray digital clock still behaves erratic.
Edit: I noticed that it happens with compiz window manager. I tried metacity, it records the clock well.
Edit2: It also fails to capture the digital clock properly in Gala, Mutter, GnomeShell window managers.
How to reproduce:

% ffmpeg -video_size 68x26 -framerate 25 -f x11grab -i :0.0+1157,770 output.mp4

ffmpeg version 4.2.4-1ubuntu0.1 Copyright (c) 2000-2020 the FFmpeg developers
  built with gcc 9 (Ubuntu 9.3.0-10ubuntu2)
  configuration: --prefix=/usr --extra-version=1ubuntu0.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-nvenc --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared

built on Ubuntu 20.04

Patches should be submitted to the ffmpeg-devel mailing list and not this bug tracker.

[Atilla Karaca]

Though I captured this video at 18:24 it still shows the still frame at 17:41:30

[Marton Balint]

Doubtful that this is a bug in ffmpeg/x11grab indev if it only affects compiz. You should somehow confirm that this is indeed an issue in the x11grab input device of ffmpeg.

[Atilla Karaca]

Replying to Marton Balint:

Doubtful that this is a bug in ffmpeg/x11grab indev if it only affects compiz. You should somehow confirm that this is indeed an issue in the x11grab input device of ffmpeg.

Thank you for responding. I tried capturing it with a number of different window managers. It captures well with Metacity and Marco but fails with Gala, Mutter, GnomeShell and Compiz which have animation effects. IMHO it might be related to GL.

[Atilla Karaca]

Replying to Michael Niedermayer:
Greetings. It also fails to capture the digital clock properly in Gala, Mutter, GnomeShell window managers.

[Atilla Karaca]

I had /usr/share/X11/xorg.conf.d/20-intel_flicker_fix.conf file with the following content:

Section "Device"
  Identifier  "Intel Graphics"
  Driver      "intel"
  Option      "AccelMethod"  "sna"
  Option      "TearFree"     "true"
  Option      "DRI"    "3"
EndSection

I replaced Option "DRI" "3" with Option "DRI" "2"
and created a ~/.drirc with the following content:

<device screen="0" driver="dri2">
        <application name="Default">
                <option name="vblank_mode" value="0"/>
        </application>
</device>

It fixed the issue for me.