vo_gpu: make it possible to load multiple hwdec interop drivers

Make the VO<->decoder interface capable of supporting multiple hwdec
APIs at once. The main gain is that this simplifies autoprobing a lot.
Before this change, it could happen that the VO loaded the "wrong" hwdec
API, and the decoder was stuck with the choice (breaking hw decoding).
With the change applied, the VO simply loads all available APIs, so
autoprobing trickery is left entirely to the decoder.

In the past, we were quite careful about not accidentally loading the
wrong interop drivers. This was in part to make sure autoprobing works,
but also because libva had this obnoxious bug of dumping garbage to
stderr when using the API. libva was fixed, so this is not a problem
anymore.

The --opengl-hwdec-interop option is changed in various ways (again...),
and renamed to --gpu-hwdec-interop. It does not have much use anymore,
other than debugging. It's notable that the order in the hwdec interop
array ra_hwdec_drivers[] still matters if multiple drivers support the
same image formats, so the option can explicitly force one, if that
should ever be necessary, or more likely, for debugging. One example are
the ra_hwdec_d3d11egl and ra_hwdec_d3d11eglrgb drivers, which both
support d3d11 input.

vo_gpu now always loads the interop lazily by default, but when it does,
it loads them all. vo_opengl_cb now always loads them when the GL
context handle is initialized. I don't expect that this causes any
problems.

It's now possible to do things like changing between vdpau and nvdec
decoding at runtime.

This is also preparation for cleaning up vd_lavc.c hwdec autoprobing.
It's another reason why hwdec_devices_request_all() does not take a
hwdec type anymore.

1 files changed, 4 insertions, 8 deletions

diff --git a/player/command.c b/player/command.c
index 569272c680..9017278286 100644
--- a/player/command.c
+++ b/player/command.c
@@ -2475,14 +2475,10 @@ static int mp_property_hwdec_interop(void *ctx, struct m_property *prop,
     if (!mpctx->video_out || !mpctx->video_out->hwdec_devs)
         return M_PROPERTY_UNAVAILABLE;
 
-    struct mp_hwdec_ctx *hwctx =
-        hwdec_devices_get_first(mpctx->video_out->hwdec_devs);
-
-    const char *name = hwctx ? hwctx->driver_name : NULL;
-    if (!name && hwctx)
-        name = m_opt_choice_str(mp_hwdec_names, hwctx->type);
-
-    return m_property_strdup_ro(action, arg, name);
+    char *names = hwdec_devices_get_names(mpctx->video_out->hwdec_devs);
+    int res = m_property_strdup_ro(action, arg, names);
+    talloc_free(names);
+    return res;
 }
 
 /// Helper to set vo flags.