Execute GL calls without marshalling them to the context thread. In the cocoa
and eagl backends calling gst_gl_context_activate is cheap and therefore calling
it on the current thread and serializing GL calls with a per-context lock is
more efficient (faster and has less overhead) than marshalling everything to the
context thread.
This optimization cuts a large overhead in g_poll (continuously waking up the
context thread) and in g_mutex_*/g_cond_* (waiting for results from the context
thread).
Intended for use with wrapped contexts that are created shared with gst's
gl contexts in order to manage the internal sharegroup state correctly.
e.g. with caopengllayer (which is used in glimagesink and caopengllayersink
on OS X), we create a CGL context from the gst context and the sharing state
was not being correctly set on either GL context and gst_gl_context_is_shared()
was always returning FALSE.
With 11fb4fff80 only flushing with multiple
shared contexts, the required flush was not occuring causing screen
corruption or stuttering.
Note: this didn't affect GST_GL_API=opengl pipelines
https://bugzilla.gnome.org/show_bug.cgi?id=762620
- glimagesink needs to be able to resize the viewport on aspect ratio
changes resulting from either caps changes or 3d output mode changes.
- Performing a glViewport outside the GstGLWindow::resize callback
will not have the winsys' stack of viewports required to correctly
place the output frame.
Provide a function to request a resize on the next draw event from the
winsys.
Also track size changes inside the base GstGLWindow class rather
than in each subclass.
https://bugzilla.gnome.org/show_bug.cgi?id=755111
They require to get_proc_address some functions through the
platform specific {glX,egl}GetProcAddress rather than the default
GL library symbol lookup.
Otherwise we could end up being mistaken for the diference between a
gl3 and a gl2 context resulting in a failure getting the list of
extensions from the wrapped context due to the difference between
glGetString and glGetStringi for the GL_EXTENSIONS token.
https://bugzilla.gnome.org/show_bug.cgi?id=749728
Otherwise the pipeline stalls when running
more than one glimagesink with gst-launch.
Also only register the custom nsapp loop
when setting up the nsapp from gstgl.
This fix a very slow rendering rate regression that only
happens when using gst-launch, i.e. in the case where
the main thread does not run any NSApp loop.
Git bisect reported it has been introduced by the commit
e10d2417e2:
"move to CGL and CAOpenGLLayer for rendering".
Then the commit 7d46357627:
"gstglwindow_cocoa: fix slow render rate" attempted to fix
the slow rendering rate problem when using gst-launch.
At least for me it does not work. I tried several
combinations, for example to flush CA transactions in the
custom app loop, as mentioned in the doc, but the only solution
that fixes the slow rendering is by reducing the loop latency.
From what I tested, no need to put less than 60ms, even if the
framerate has an interval much lower (16.6ms for 60 fps).
In gst_gl_window_cocoa_draw we used to just call setNeedsDisplay:YES. That was
creating an implicit CA transaction which was getting committed at the next
runloop iteration. Since we don't know how often the main runloop is running,
and when we run it implicitly (from gst_gl_window_cocoa_nsapp_iteration) we only
do so every 200ms, use an explicit CA transaction instead and commit it
immediately. CA transactions nest and debounce automatically so this will never
result in extra work.
Depending on the platform, it was only ever implemented to 1) set a
default surface size, 2) resize based on the video frame or 3) nothing.
Instead, provide a set_preferred_size () that elements/applications
can use to request a certain size which may be ignored for
videooverlay/other cases.
Removes the use of NSOpenGL* variety and functions. Any Cocoa
specific functions that took/returned a NSOpenGL* object now
take/return the CGL equivalents.
The hack causes deadlocks and other interesting problems and it really
can only be fixed properly inside GLib. We will include a patch for
GLib in our builds for now that handles this, and hopefully at some
point GLib will also merge a proper solution.
A proper solution would first require to refactor the polling in
GMainContext to only provide a single fd, e.g. via epoll/kqueue
or a thread like the one added by our patch. Then this single
fd could be retrieved from the GMainContext and directly integrated
into a NSRunLoop.
https://bugzilla.gnome.org/show_bug.cgi?id=741450https://bugzilla.gnome.org/show_bug.cgi?id=704374
