This attempts to implement the gtkglsink element on Windows using WGL,
as there were some more gotchas that are along the way, since we need to
juggle with libepoxy along the way, meaning that we need a recent
GTK+-3.24.x for this to work properly, i.e. the upcoming GTK+-3.24.43.
Since we are essentially using an overlay compositor only during
rendering, move its initialization and destruction into the
gtk_gst_gl_widget_render() function, so that things are safer as we are
doing things across threads between gstreamer (gst-gl) and GTK, as GL
operations, as above, have more gotchas on Windows.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/4289>
gtk_gl_area_get_error() doesn't return a copy of the error, but just the
error. If initialising OpenGL fails, then GtkGstGLWidget will consume
the error, and cause GTK to try and display freed memory.
==50914== Invalid read of size 8
==50914== at 0x4C4CB8A: gtk_gl_area_draw_error_screen (gtkglarea.c:663)
==50914== by 0x4C4CB8A: gtk_gl_area_draw (gtkglarea.c:687)
==50914== by 0x4E061CA: gtk_widget_draw_internal (gtkwidget.c:7084)
==50914== by 0x4BAEFB1: gtk_container_propagate_draw (gtkcontainer.c:3854)
==50914== by 0x4D4B6BF: gtk_stack_render (gtkstack.c:2207)
==50914== by 0x4BB4B03: gtk_css_custom_gadget_draw (gtkcsscustomgadget.c:159)
==50914== by 0x4BBA4C4: gtk_css_gadget_draw (gtkcssgadget.c:885)
==50914== by 0x4D4D780: gtk_stack_draw (gtkstack.c:2119)
==50914== by 0x4E061CA: gtk_widget_draw_internal (gtkwidget.c:7084)
==50914== by 0x4BAEFB1: gtk_container_propagate_draw (gtkcontainer.c:3854)
==50914== by 0x4BAF0C3: gtk_container_draw (gtkcontainer.c:3674)
==50914== by 0x4E061CA: gtk_widget_draw_internal (gtkwidget.c:7084)
==50914== by 0x4BAEFB1: gtk_container_propagate_draw (gtkcontainer.c:3854)
==50914== Address 0x187a0818 is 8 bytes inside a block of size 16 free'd
==50914== at 0x48480E4: free (vg_replace_malloc.c:872)
==50914== by 0x49A5B8C: g_free (gmem.c:218)
==50914== by 0x49C1013: g_slice_free1 (gslice.c:1183)
==50914== by 0x4990DE4: g_error_free (gerror.c:870)
==50914== by 0x4990FE9: g_clear_error (gerror.c:1052)
==50914== by 0x1A489780: _get_gl_context (gtkgstglwidget.c:540)
==50914== by 0x1A4863CB: gst_gtk_invoke_func (gstgtkutils.c:39)
==50914== by 0x49A3834: g_main_context_invoke_full (gmain.c:6137)
==50914== by 0x1A486450: gst_gtk_invoke_on_main (gstgtkutils.c:59)
==50914== by 0x1A48A29E: gtk_gst_gl_widget_init_winsys (gtkgstglwidget.c:632)
==50914== by 0x1A4887E7: gst_gtk_gl_sink_start (gstgtkglsink.c:267)
==50914== by 0x6579810: gst_base_sink_change_state (gstbasesink.c:5662)
==50914== Block was alloc'd at
==50914== at 0x484586F: malloc (vg_replace_malloc.c:381)
==50914== by 0x49A9278: g_malloc (gmem.c:125)
==50914== by 0x49C1BA5: g_slice_alloc (gslice.c:1072)
==50914== by 0x49C3BCC: g_slice_alloc0 (gslice.c:1098)
==50914== by 0x499096B: g_error_allocate (gerror.c:708)
==50914== by 0x4990AF1: UnknownInlinedFun (gerror.c:722)
==50914== by 0x4990AF1: g_error_copy (gerror.c:892)
==50914== by 0x4C4B9F9: gtk_gl_area_set_error (gtkglarea.c:1036)
==50914== by 0x4C4BAF7: gtk_gl_area_real_create_context (gtkglarea.c:346)
==50914== by 0x4B21B28: _gtk_marshal_OBJECT__VOIDv (gtkmarshalers.c:2730)
==50914== by 0x4920B78: UnknownInlinedFun (gclosure.c:893)
==50914== by 0x4920B78: g_signal_emit_valist (gsignal.c:3406)
==50914== by 0x4920CB2: g_signal_emit (gsignal.c:3553)
==50914== by 0x4C4B927: gtk_gl_area_realize (gtkglarea.c:308)
Reproduced by running:
MESA_GL_VERSION_OVERRIDE=2.7 totem
See https://gitlab.gnome.org/GNOME/totem/-/issues/522
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2565>
Guard against the orientation not coming from an inexistant tag, nor
from the application (rotation set to "auto") which caused an assertion.
When the application requests the auto rotation method, make sure it is
resolved to a rotation that's applicable.
ERROR:gstreamer/subprojects/gst-plugins-good/ext/gtk/gtkgstglwidget.c:745:gtk_gst_gl_widget_set_rotate_method: code should not be reached
Fixes: 103ceb853a
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1134>
