[3.0] opengl: fix swizzle
Backport !1634 (merged) to VLC3.
This requires an additional commit to explicitly define the swizzle for the first texture (partial backport of 1e721747).
Backport !1634 (merged) to VLC3.
This requires an additional commit to explicitly define the swizzle for the first texture (partial backport of 1e721747).
VideoLAN code repository instance