Since vo_rpi is going to be deprecated, better port its features to the
vo_opengl backend.
The most tricky part is the fact that recreating dispmanx elements will
conflict with the GL context. Fortunately, RPI's EGL support is
reasonably compliant, and we can transplant the context to newly created
dispmanx elements, making this much easier. This means unlike vo_rpi,
the GL state will actually not be recreated.
This overlay support specifically skips the OpenGL rendering chain, and
uses GL rendering only for OSD/subtitles. This is for devices which
don't have performant GL support.
hwdec_rpi.c contains code ported from vo_rpi.c. vo_rpi.c is going to be
deprecated. I left in the code for uploading sw surfaces (as it might
be slightly more efficient for rendering sw decoded video), although
it's dead code for now.
Do this to make the license situation less confusing.
This change should be of no consequence, since LGPL is compatible with
GPL anyway, and making it LGPL-only does not restrict the use with GPL
code.
Additionally, the wording implies that this is allowed, and that we can
just remove the GPL part.
Untested, but should be fine. Broken by commit 0a0bb905.
Also fix the include statement in context_rpi.c, which caused another
compilation failure. Also untested. (Because I'm lazy.)
Fixes#2638.
wm4