Gnome Shell screencast doesn't work at desktop resolution 4880x1085

[Daniel Ninofranco]

https://gitlab.gnome.org/GNOME/mutter/issues/263

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Ubuntu 18 shows only black output on 3 monitor display screencast. I'm using desktop with videocard with 3 display output (HDMI, VGA, DVI). On dual monitor, screecast works fine while on 3 monitors the output is only black screen.
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ProblemType: Bug
ApportVersion: 2.20.9-0ubuntu7.2
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
DisplayManager: gdm3
DistroRelease: Ubuntu 18.04
GsettingsChanges:
 b'org.gnome.shell' b'favorite-apps' redacted by apport
 b'org.gnome.desktop.interface' b'gtk-im-module' b"'gtk-im-context-simple'"
InstallationDate: Installed on 2018-06-08 (66 days ago)
InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
Package: gnome-shell 3.28.2-0ubuntu0.18.04.1
PackageArchitecture: amd64
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_PH.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 4.15.0-23.25-generic 4.15.18
Tags: bionic
Uname: Linux 4.15.0-23-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo
_MarkForUpload: True

[Daniel van Vugt (vanvugt)]

1. What is the resolution of your monitors?

2. Please run this command to send us more information:

   apport-collect 1786757

[Daniel Ninofranco (daniel.ninofranco)]

apport information

[Daniel Ninofranco (daniel.ninofranco)]

apport information

[Daniel Ninofranco (daniel.ninofranco)]

Monitor 1 1600 x 900 VGA
Monitor 2 1600 x 900 VGA
Monitor 3 1680 x 1050 DVI

[Daniel van Vugt (vanvugt)]

When you say "screencast" what tool are you using there?

[Daniel van Vugt (vanvugt)]

Please also run these commands and send us the output:

  glxinfo

  xrandr

[Daniel Ninofranco (daniel.ninofranco)]

I'm using the built-in screencast by pressing CTRL+ALT+SHIFT+R

[Daniel Ninofranco (daniel.ninofranco)]

See attached xrandr output

[Daniel Ninofranco (daniel.ninofranco)]

See attached glxinfo

[Daniel van Vugt (vanvugt)]

Thanks.

Your desktop size of 4880x1085 is likely the factor here. I find that surprising because apparently the AMD Cedar GPU shouldn't max out until textures reach 16384x16384 [1].

Maybe it's a video encoding limitation then, such as [2] [3].

The Gnome shell developers might know already, so please report the bug to them at:
https://gitlab.gnome.org/GNOME/mutter/issues

[1] https://www.x.org/wiki/RadeonFeature/
[2] https://en.wikipedia.org/wiki/H.264/MPEG-4_AVC#Levels
[3] https://en.wikipedia.org/wiki/High_Efficiency_Video_Coding#Tiers_and_levels

[Daniel van Vugt (vanvugt)]

and then tell us the ID of the new bug.

[Daniel van Vugt (vanvugt)]

Got it, thanks:
https://gitlab.gnome.org/GNOME/mutter/issues/263

[Daniel Ninofranco (daniel.ninofranco)]

Do we have an update on this issue?

[Daniel Ninofranco (daniel.ninofranco)]

Any update on this bug?

[Daniel van Vugt (vanvugt)]

Any work on this bug will occur upstream, so you should ask there instead:

https://gitlab.gnome.org/GNOME/mutter/issues/263

[Daniel van Vugt (vanvugt)]

Thank you for reporting this bug to Ubuntu.

Ubuntu 18.04 (bionic) reached end-of-standard-support on May 31, 2023.

See this document for currently supported Ubuntu releases:
https://wiki.ubuntu.com/Releases

We appreciate that this bug may be old and you might not be interested in discussing it anymore. But if you are then please upgrade to the latest Ubuntu version and re-test. If you then find the bug is still present in the newer Ubuntu version, please add a comment here telling us which new version it is in.