vo_opengl, vo_opengl_cb: better hwdec interop backend selection

Introduce the --opengl-hwdec-interop option, which replaces
--hwdec-preload. The new option allows explicit selection of the interop
backend.

This is relatively complex, and I would have preferred not to add this,
but it's probably useful to debug certain problems. In exchange, the
"new" option documents that pretty much any but the simplest use of it
will not be forward compatible.

1 files changed, 5 insertions, 2 deletions

diff --git a/DOCS/man/input.rst b/DOCS/man/input.rst
index 70a05dcaef..68f5ae53e8 100644
--- a/DOCS/man/input.rst
+++ b/DOCS/man/input.rst
@@ -1331,8 +1331,8 @@ Property list
     This is known only once the VO has opened (and possibly later). With some
     VOs (like ``opengl``), this might be never known in advance, but only when
     the decoder attempted to create the hw decoder successfully. (Using
-    ``--hwdec-preload`` can load it eagerly.) If there are multiple drivers
-    loaded, they will be separated by ``,``.
+    ``--opengl-hwdec-interop`` can load it eagerly.) If there are multiple
+    drivers loaded, they will be separated by ``,``.
 
     If no VO is active or no interop driver is known, this property is
     unavailable.
@@ -1341,6 +1341,9 @@ Property list
     multiple interop drivers for the same hardware decoder, depending on
     platform and VO.
 
+    This is somewhat similar to the ``--opengl-hwdec-interop`` option, but
+    it returns the actually loaded backend, not the value of this option.
+
 ``video-format``
     Video format as string.