filters: lavfi: allow hwdec_interop selection for filters

Today, lavfi filters are provided a hw_device from the first
hwdec_interop that was loaded, regardless of whether it's the right one
or not. In most situations where a hardware based filter is used, we
need more control over the device.

In this change, a `hwdec_interop` option is added to the lavfi wrapper
filter configuration and this is used to pick the correct hw_device to
inject into the filter or graph (in the case of a graph, all filters
get the same device).

Note that this requires the use of the explicit lavfi syntax to allow
for the extra configuration.

eg:

```
mpv --vf=hwupload
```

becomes

```
mpv --vf=lavfi=[hwupload]:hwdec_interop=cuda-nvdec
```

or

```
mpv --vf=lavfi-bridge=[hwupload]:hwdec_interop=cuda-nvdec
```

1 files changed, 1 insertions, 1 deletions

diff --git a/player/loadfile.c b/player/loadfile.c
index a4ef62f2aa..da0d8b3a28 100644
--- a/player/loadfile.c
+++ b/player/loadfile.c
@@ -1257,7 +1257,7 @@ static int reinit_complex_filters(struct MPContext *mpctx, bool force_uninit)
     }
 
     struct mp_lavfi *l =
-        mp_lavfi_create_graph(mpctx->filter_root, 0, false, NULL, graph);
+        mp_lavfi_create_graph(mpctx->filter_root, 0, false, NULL, NULL, graph);
     if (!l)
         goto done;
     mpctx->lavfi = l->f;