This is functionally a no-op, but works around a driver bug that
prevents use of eglQueryDisplayAttribEXT. This makes us more likely to
not trigger the driver bug and that gs_enum_adapters works correctly.
This adds gs_enum_adapters and gs_get_adapter_count to the opengl
backend and promotes these to multiplatform graphics functions.
However we need to make an internal device change, device_enum_adapters
must pass in the current device on opengl to ensure that adapter #0 is
the display adapter. We do this to avoid changes to plugins already
checking against obs_video_info.adapter which is always 0 and expected
to be the device OBS was initialized on.
The actual implementation reports the dri render node (or /Software).
This allows plugins to query non-video features of the adapters like
VA-API/NVENC/etc or other cross device functionality. `/Software` is
chosen to avoid opening random files in the current directory if its
passed along as a file path like the regular dri render nodes.
Currently, the X11 display may be leaked when the X11/EGL
platform is destroyed. Fix that by calling XCloseDisplay()
to free it.
Fixes: 2fd8a6df55 ("libobs-opengl: Introduce the X11/EGL winsys")
The platform display is not owned by libobs, it should not
be closed. Doing so results in heap use-after-frees when
Qt components try to use it while trying to show
a message box about the failure:
info: Initializing OpenGL...
error: Failed to initialize EGL: EGL_BAD_ACCESS
error: Failed to create context!
error: device_create (GL) failed
error: Failed to initialize video. Your GPU may not be supported, or your graphics drivers may need to be updated.
=================================================================
==2320345==ERROR: AddressSanitizer: heap-use-after-free on address 0x621000018668 at pc 0x7fcb75e20d6e bp 0x7ffe88d0e910 sp 0x7ffe88d0e900
READ of size 8 at 0x621000018668 thread T0
0 0x7fcb75e20d6d in XInternAtom /.../libx11/src/IntAtom.c:175
1 0x7fcb6bf5edfd in Kvantum::ThemeConfig::getCompositeSpec()
2 0x7fcb6bf0eb19 in Kvantum::Style::setSurfaceFormat(QWidget*) const
3 0x7fcb6bf11bae in Kvantum::Style::styleHint(QStyle::StyleHint, QStyleOption const*, QWidget const*, QStyleHintReturn*) const
4 0x5585cbce70b8 in OBSIgnoreWheelProxyStyle::styleHint(QStyle::StyleHint, QStyleOption const*, QWidget const*, QStyleHintReturn*) const /.../obs-studio/UI/obs-proxy-style.cpp:88
5 0x7fcb85826515 (/usr/lib/libQt6Widgets.so.6+0x226515)
6 0x7fcb859dbf1d (/usr/lib/libQt6Widgets.so.6+0x3dbf1d)
7 0x7fcb859dc5f0 in QMessageBox::QMessageBox(...)
8 0x7fcb859dc6b1 (/usr/lib/libQt6Widgets.so.6+0x3dc6b1)
9 0x5585cbd2fb31 in OBSErrorBoxva /.../obs-studio/UI/qt-wrappers.cpp:48
10 0x5585cbd2fd34 in OBSErrorBox(QWidget*, char const*, ...) /.../obs-studio/UI/qt-wrappers.cpp:55
11 0x5585cbcc3f36 in run_program /.../obs-studio/UI/obs-app.cpp:2475
12 0x5585cbcc52b4 in main /.../obs-studio/UI/obs-app.cpp:3358
13 0x7fcb82e3c28f (/usr/lib/libc.so.6+0x2328f)
14 0x7fcb82e3c349 in __libc_start_main
15 0x5585cbbd2f54 in _start
Fixes: 137966e01f ("libobs-opengl: Try to use the platform display if available")
Previously we passed the wrong display and formats/modifiers could not
be queried. This prevented pipewire sources from negotiating texture
sharing on x11.
When using EGL the mesa+nvidia stack are unable to offload 32bit
framebuffers despite having this capability on GLX. In practice the X11
server does not support alpha windows so we dont need the alpha
component in our framebuffer. We previously had alpha specified in our
framebuffer since we do alpha texturing but testing shows this isnt
required for mesa/intel or nvidia drivers and we must pick a 24bit
config for users to enable render offloading for mixed gpu systems.
fixes#6984
Without this we get somewhat misleading errors from later in the
swapchain creation when this fails. This is currently happening for
users attempting to use multi-gpu with prime offloading on nvidia.
When sharing DMA-BUFs it is required the announce the underlying
hardware capabilities via supported modifiers.
Add new device_query_dmabuf_capabilities vfunc to gs_exports and connect it
to the egl implementation stubs in the supported render platforms. Add a new
public method gs_query_dmabuf_capabilities() that calls the vfunc above.
Add new device_query_dmabuf_modifiers vfunc to gs_exports and connect it
to the egl implementation in the supported render platforms. Add a new
public method gs_query_dmabuf_modifiers() that calls the vfunc above.
This adds the drmbuf format as a parameter separate from the obs texture
format that will be used. drmbuf's may have a variety of formats that we
need to pass correctly to get a usable texture which may correspond to
multi-platform texture formats.
Implement device_texture_create_from_dmabuf for EGL/X11 and EGL/Wayland.
The code is shared between them, in a new gl-egl-common.c file.
This is currently limited to a few common RGB(A) formats for now, which
seems to cover most use cases.
DMA-BUF is a widespread Linux buffer sharing mechanism. It is what's
commonly used zero-copy screen sharing by Wayland compositors.
Add a new 'device_texture_create_from_dmabuf' vfunc to gs_exports,
and stub implementations to libobs-opengl. Add a new public method
gs_texture_create_from_dmabuf() that calls this vfunc.
Introduce the EGL/X11 winsys, and use it when the OBS_USE_EGL environment
variable is defined. This variable is only temporary, for future commits
will add a proper concept of platform.
All the EGL/X11 code is authored by Ivan Avdeev <me@w23.ru>.
