New API:
- gst_gl_context_get_config()
- gst_gl_context_request_config()
A GL context configuration is a GstStructure that has some well-known
names for common values that can also be extended in platform-specific
ways if necessary.
Wrapped OpenGL contexts may be able to retrieve the GL context
configuration depending on the platform. If that information is
available, GstGLContext will attempt to create an context that matches
the shared OpenGL context config unless gst_gl_context_request_config()
has been called.
A new environment variable 'GST_GL_CONFIG' will be read to influence the
configuration chosen. The environment variable will only be used as a
fallback if gst_gl_context_request_config() has not been called.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/-/merge_requests/809>
Since we started depending on GLib 2.44, we can be sure this macro is
defined (it will be a no-op on compilers that don't support it). For
plugins we should just start using `G_DECLARE_FINAL_TYPE` which means we
no longer need the macro there, but for most types in base/gst-libs we
don't want to break ABI, which means it's better to just keep it like it
is (and use the `#ifdef` instead).
Except for gst/gl/gstglfuncs.h
It is up to the client app to include these headers.
It is coherent with the fact that gstreamer-gl.pc does not
require any egl.pc/gles.pc. I.e. it is the responsability
of the app to search these headers within its build setup.
For example gstreamer-vaapi includes explicitly EGL/egl.h
and search for it in its configure.ac.
For example with this patch, if an app includes the headers
gst/gl/egl/gstglcontext_egl.h
gst/gl/egl/gstgldisplay_egl.h
gst/gl/egl/gstglmemoryegl.h
it will *no longer* automatically include EGL/egl.h and GLES2/gl2.h.
Which is good because the app might want to use the gstgl api only
without the need to bother about gl headers.
Also added a test: cd tests/check && make libs/gstglheaders.check
https://bugzilla.gnome.org/show_bug.cgi?id=784779
Make a bunch of symbols private that are currently leaked
accidentally because they have a gst_* prefix and are used
internally. We mark those we can't make static with
G_GNUC_INTERNAL so that they get hidden with the autotools
build as well (although we could just pass -fvisibility=hidden
there too).
When (re)activating the context, the backing window handle might have changed.
If that happened, destroy the previous surface and create a new one
https://bugzilla.gnome.org/show_bug.cgi?id=745090
* picked from old libgstegl:
- GstEGLImageMemory
- GstEGLImageAllocator
- last_buffer management from removed GstEGLImageBufferPool
* add-ons:
- GstEGLImageMemory now old a reference on GstGLContext
so that it can delete the EGLImage and its gltexture source
while having the associated gl context being current.
- add EGLImage support for GstVideoGLTextureUploadMeta which
mainly call EGLImageTargetTexture2D
- GstGLBufferPool now supports GstEGLImageAllocator
- glimagesink / glfilters / etc.. now propose GstEGLImageAllocator
to upstream
https://bugzilla.gnome.org/show_bug.cgi?id=703343
