It may be an old thread, but I feel that the question has not received the proper answer. It may not be a "frame number", but it gives you the "position" of the video that you could transmit. I use it to sync two videos. This is for a media player that has already been added to the VB form called AxWindowsMediaPlayer1. I'm sure something like this can be called in C #
Dim position As Double position = AxWindowsMediaPlayer1.Ctlcontrols.currentPosition
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