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
```

0 files changed, 0 insertions, 0 deletions