Built and installed on Fedora 31, but does not work about obs-gnome-screencast

[fzwoch]

Your scene is using the xshm_input source which is the default capture plugin from OBS and is not related to this plugin. Also the plugin is not listed at start up so it is likely you have not installed the plugin in the correct folder for your OBS installation.

[djnotes]

Yes, it seems obs does pick up obs-plugins from /usr/local, rather from /usr/lib64. Nevertheless, how to switch from xshm_input to this plugin?

[fzwoch]

It should appear as its own plugin named GNOME Screencast or similar

[djnotes]

Hmm, don't see anything like that in the layout. Will it make any difference if I build obs from source?

By the way copied /usr/local/lib/obs-plugins/gnome-screencast.so to /usr/lib64/obs-plugins/gnome-screencast.so and seems like it is now loaded but still fails to show a preview. Here's the output:

QSocketNotifier: Can only be used with threads started with QThread
Attempted path: share/obs/obs-studio/locale/en-US.ini
Attempted path: /usr/share/obs/obs-studio/locale/en-US.ini
Attempted path: share/obs/obs-studio/locale.ini
Attempted path: /usr/share/obs/obs-studio/locale.ini
Attempted path: share/obs/obs-studio/themes/Dark.qss
Attempted path: /usr/share/obs/obs-studio/themes/Dark.qss
info: CPU Name: Intel(R) Core(TM) i5-6200U CPU @ 2.30GHz
info: CPU Speed: 2700.068MHz
info: Physical Cores: 2, Logical Cores: 4
info: Physical Memory: 7858MB Total, 222MB Free
info: Kernel Version: Linux 5.3.7-301.fc31.x86_64
info: Distribution: Fedora 31
info: Window System: X11.0 - vendor string: Fedora Project - vendor release: 12005000
info: Portable mode: false
Attempted path: share/obs/obs-studio/themes/Dark/no_sources.svg
Attempted path: /usr/share/obs/obs-studio/themes/Dark/no_sources.svg
QMetaObject::connectSlotsByName: No matching signal for on_advAudioProps_clicked()
QMetaObject::connectSlotsByName: No matching signal for on_advAudioProps_destroyed()
QMetaObject::connectSlotsByName: No matching signal for on_program_customContextMenuRequested(QPoint)
info: OBS 24.0.3 (linux)
info: ---------------------------------
info: ---------------------------------
info: audio settings reset:
	samples per sec: 44100
	speakers:        1
info: ---------------------------------
info: Initializing OpenGL...
info: Loading up OpenGL on adapter Intel Open Source Technology Center Mesa DRI Intel(R) HD Graphics 520 (Skylake GT2) 
info: OpenGL loaded successfully, version 4.5 (Core Profile) Mesa 19.2.1, shading language 4.50
info: ---------------------------------
info: video settings reset:
	base resolution:   1920x1080
	output resolution: 1920x1080
	downscale filter:  Bilinear
	fps:               30/1
	format:            NV12
	YUV mode:          601/Partial
info: NV12 texture support not available
info: Audio monitoring device:
	name: Default
	id: default
info: ---------------------------------
warning: Failed to load 'en-US' text for module: 'decklink-ouput-ui.so'
libDeckLinkAPI.so: cannot open shared object file: No such file or directory
info: No blackmagic support
error: os_dlopen(libnvidia-encode.so.1->libnvidia-encode.so.1): libnvidia-encode.so.1: cannot open shared object file: No such file or directory

info: FFMPEG VAAPI supported
info: VLC found, VLC video source enabled
info: ---------------------------------
info:   Loaded Modules:
info:     vlc-video.so
info:     text-freetype2.so
info:     rtmp-services.so
info:     obs-x264.so
info:     obs-transitions.so
info:     obs-outputs.so
info:     obs-filters.so
info:     obs-ffmpeg.so
info:     linux-v4l2.so
info:     linux-pulseaudio.so
info:     linux-jack.so
info:     linux-decklink.so
info:     linux-capture.so
info:     linux-alsa.so
info:     image-source.so
info:     gnome-screencast.so
info:     frontend-tools.so
info:     decklink-ouput-ui.so
info: ---------------------------------
info: ==== Startup complete ===============================================
info: All scene data cleared
info: ------------------------------------------------
info: pulse-input: Server name: 'pulseaudio 13.0-rebootstrapped'
info: pulse-input: Audio format: s16le, 48000 Hz, 2 channels
info: pulse-input: Started recording from 'alsa_input.usb-Burr-Brown_from_TI_USB_Audio_CODEC-00.iec958-stereo'
info: Switched to scene 'Scene'
info: ------------------------------------------------
info: Loaded scenes:
info: - scene 'Scene':
info: ------------------------------------------------
error: Failed to fetch parent window geometry!
error: gl_platform_init_swapchain  failed
error: obs_display_init: Failed to create swap chain
error: Failed to fetch parent window geometry!
error: gl_platform_init_swapchain  failed
error: obs_display_init: Failed to create swap chain
error: Failed to fetch parent window geometry!
error: gl_platform_init_swapchain  failed
error: obs_display_init: Failed to create swap chain
error: Failed to fetch parent window geometry!
error: gl_platform_init_swapchain  failed
error: obs_display_init: Failed to create swap chain
error: Failed to fetch parent window geometry!
error: gl_platform_init_swapchain  failed
error: obs_display_init: Failed to create swap chain
info: adding 23 milliseconds of audio buffering, total audio buffering is now 23 milliseconds (source: Mic/Aux)

error: Failed to fetch parent window geometry!
error: gl_platform_init_swapchain  failed
error: obs_display_init: Failed to create swap chain
qt.qpa.wayland: Non-toplevel surfaces can't request window states
qt.qpa.wayland: Non-toplevel surfaces can't request window states
error: Failed to fetch parent window geometry!
error: gl_platform_init_swapchain  failed
error: obs_display_init: Failed to create swap chain

[fzwoch]

It loads fine and without error. So it should be part of the list of sources when you try to add one to the scene. It should not matter if you build OBS yourself - I do that too. However you have a lot of error coming from OBS itself so I can't say whats up with them.

[djnotes]

Yes, gotcha, so this plugin is kind of a workaround. There is a new option Gnome Screencast that once loaded starts to record the desktop. I hope I could see a preview integrated inside the application as with xshm.

[fzwoch]

You do if your OBS is not broken. I assume your Qt tries to use wayland instead of X11 - I think thats known to be broken on OBS.