Bernhard Kölbl (@besentv) commented about dlls/mfmediaengine/tests/mfmediaengine.c:
+ EnterCriticalSection(&impl->cs); + + if (!(flags & MFT_SET_TYPE_TEST_ONLY)) + { + if (impl->media_type_in) + IMFMediaType_Release(impl->media_type_in); + + impl->media_type_in = type; + IMFMediaType_AddRef(impl->media_type_in); + + /* Idk why, but Windows apparently expects this function to also set an output type... */ + if (impl->media_type_out) + IMFMediaType_Release(impl->media_type_out); + + impl->media_type_out = type; + IMFMediaType_AddRef(impl->media_type_out); Oh and it still doesn't work without this.
-- https://gitlab.winehq.org/wine/wine/-/merge_requests/2778#note_36992