winegstreamer/video_processor: Allow clearing input / output types.

dlls/winegstreamer/video_processor.c

@@ -347,6 +347,22 @@ static HRESULT WINAPI video_processor_SetInputType(IMFTransform *iface, DWORD id
 
     TRACE("iface %p, id %#lx, type %p, flags %#lx.\n", iface, id, type, flags);
 
+    if (!type)
+    {
+        if (impl->input_type)
+        {
+            IMFMediaType_Release(impl->input_type);
+            impl->input_type = NULL;
+        }
+        if (impl->wg_transform)
+        {
+            wg_transform_destroy(impl->wg_transform);
+            impl->wg_transform = 0;
+        }
+
+        return S_OK;
+    }
+
     if (FAILED(IMFMediaType_GetGUID(type, &MF_MT_MAJOR_TYPE, &major))
             || !IsEqualGUID(&major, &MFMediaType_Video))
         return E_INVALIDARG;
@@ -390,6 +406,22 @@ static HRESULT WINAPI video_processor_SetOutputType(IMFTransform *iface, DWORD i
 
     TRACE("iface %p, id %#lx, type %p, flags %#lx.\n", iface, id, type, flags);
 
+    if (!type)
+    {
+        if (impl->output_type)
+        {
+            IMFMediaType_Release(impl->output_type);
+            impl->output_type = NULL;
+        }
+        if (impl->wg_transform)
+        {
+            wg_transform_destroy(impl->wg_transform);
+            impl->wg_transform = 0;
+        }
+
+        return S_OK;
+    }
+
     if (FAILED(IMFMediaType_GetGUID(type, &MF_MT_MAJOR_TYPE, &major))
             || !IsEqualGUID(&major, &MFMediaType_Video))
         return E_INVALIDARG;