Allegro's HEVC implementation defines a superset of the profiles and
enums from the Android implementation.
Properly cast to fix -Wenum-conversion warnings from clang.
https://bugzilla.gnome.org/show_bug.cgi?id=789057
OMX's allow 3rds party to define extensions using their own enums
(like OMX_VIDEO_CODINGEXTTYPE) and to be used as the general
ones (like OMX_VIDEO_CODINGTYPE).
Properly cast those to fix -Wenum-conversion warnings from some
compilers such as clang.
https://bugzilla.gnome.org/show_bug.cgi?id=789057
The OMX spec doesn't support HEVC but the OMX stack of the
zynqultrascaleplus adds it as a custom extension.
It uses the same API as the one of Android's OMX stack.
I used the H264 encoder code as a template.
https://bugzilla.gnome.org/show_bug.cgi?id=785434
