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, 8 insertions, 0 deletions

diff --git a/video/out/gpu/hwdec.h b/video/out/gpu/hwdec.h
index 34f8bc7856..0dd2e14588 100644
--- a/video/out/gpu/hwdec.h
+++ b/video/out/gpu/hwdec.h
@@ -20,6 +20,10 @@ struct ra_hwdec_ctx {
 int ra_hwdec_validate_opt(struct mp_log *log, const m_option_t *opt,
                           struct bstr name, const char **value);
 
+int ra_hwdec_validate_drivers_only_opt(struct mp_log *log,
+                                       const m_option_t *opt,
+                                       struct bstr name, const char **value);
+
 void ra_hwdec_ctx_init(struct ra_hwdec_ctx *ctx, struct mp_hwdec_devices *devs,
                        const char *opt, bool load_all_by_default);
 void ra_hwdec_ctx_uninit(struct ra_hwdec_ctx *ctx);
@@ -143,4 +147,8 @@ void ra_hwdec_mapper_free(struct ra_hwdec_mapper **mapper);
 void ra_hwdec_mapper_unmap(struct ra_hwdec_mapper *mapper);
 int ra_hwdec_mapper_map(struct ra_hwdec_mapper *mapper, struct mp_image *img);
 
+// Get the primary image format for the given driver name.
+// Returns IMGFMT_NONE if the name doesn't get matched.
+int ra_hwdec_driver_get_imgfmt_for_name(const char *name);
+
 #endif