I found the answer and I thought I should share it. I'm sorry for answering my own question, but here goes:
One can specify in the settings of the MediaCapture object, when initializing it, that it will use only the Video part:
var mediaCaptureMgr = new MediaCapture();
var captureSettings = new MediaCaptureInitializationSettings();
captureSettings.StreamingCaptureMode = StreamingCaptureMode.Video;
await mediaCaptureMgr.InitializeAsync(captureSettings);
RTFM!