`GstGLDisplayWayland` calls GstGLDisplayEGL::from_gl_display()` under
the hood (which calls `GstGLDisplayEGL::from_native()`, which calls
`eglGetPlatformDisplay()`) to retrieve the underlying `EGLDisplay`
handle, which thus far seems to be the same value as `glutin`. However,
newer `glutin 0.31` passes attributes to this function resulting in a
different handle, causing all kinds of trouble further down the line
when sharing resources between `glutin` and `gstreamer-rs` that both
operate on a distinct `EGLDisplay`.
Furthermore `GstGLDisplayEGL` thinks that it uniquely owns the
handle returned by `eglGetPlatformDisplay()` and _does not_ set
`.foreign_display = TRUE` (which `GstGLDisplayEGL::with_egl_display()`
would), causing it to call `eglTerminate()` as soon as the
`GstGLDisplay` is destroyed, leaving `glutin` dysfunctional.
To solve all of this, simply remove this wrongly-behaving class from the
example as it is not suitable for sharing an `EGLDisplay` with `glutin`.
It might however be interesting to create a different example that
showcases how to use raw window handles instead of EGL/GLX handles,
however only Wayland and any platform on EGL like Android, via
`GstGLDisplayEGL::from_native()`, support this.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer-rs/-/merge_requests/1336>
Currently only covers what is needed to keep code compiling, plus
everything caps/structure/tags related.
This avoids unnecessary heap allocations for adding the NUL-terminator
of C strings, and especially makes caps/structure handling as efficient
as in C.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer-rs/-/merge_requests/1190>
As a side-effect, this also now includes the element factory name in the
error messages instead of giving the same error string for every
factory.
Partially fixes https://gitlab.freedesktop.org/gstreamer/gstreamer-rs/-/issues/318
Also let them all go through the same, single object construction code.
When importing the prelude of a crate like `gst` the `glib` prelude is
provided too. Shedding these imports saves quite a few lines and
adheres to keeping it simple; we're not reexporting base/parent preludes
for no reason :)
