Formats map is instantiated at the end of the display
instantiation. The problem is the Wayland display which looks for a
format in a callback, before the map is populated.
If user compiles gstreamer-vaapi with DRM support, the map is
populated with a DRM display at GStreamer plugin registration. But if
not, or a VA driver is not available, the plugin will try with a
Wayland driver, which cause the NULL de-reference.
Nevertheless, in the case of no DRM support, and if the Wayland
display doesn't get a reply from the format conversion is not a
problem.
So the solution is the trivial one, check if the format map is already
populated before de-reference it.
Fixes: #977
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1606>
Instead of defining a sized array for function signature, use it
unsized (a pointer alias, basically). In this way clang warning is
silenced:
warning: ‘fill_profiles’ accessing 64 bytes in a region of size 12 [-Wstringop-overflow=]
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1357>
... in favour of dep.get_variable('foo', ..) which in some
cases allows for further cleanups in future since we can
extract variables from pkg-config dependencies as well as
internal dependencies using this mechanism.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1183>
