Nikolay Sivov (@nsivov) commented about dlls/evr/mixer.c:
if (mixer->inputs[0].media_type) IMFMediaType_Release(mixer->inputs[0].media_type); mixer->inputs[0].media_type = media_type;
mixer->inputs[0].frame_size.cx = video_desc.SampleWidth;
mixer->inputs[0].frame_size.cy = video_desc.SampleHeight;
if (FAILED(IMFMediaType_GetBlob(media_type, &MF_MT_GEOMETRIC_APERTURE,
(BYTE *)&mixer->inputs[0].aperture, sizeof(mixer->inputs[0].aperture), &size)))
The size argument is optional, existing code does not use it.