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Two of the biggies, Winamp and VLC, both have open APIs that can be used to determine the time:

SDK Contents - Winamp Developer Wiki (look at the GetOutputTime function)
VLC: LibVLC media player

That doesn't account for any fast forwarding, rewinding, pausing, etc. You need to know how many minutes/seconds into the video you are, which has to be obtained from the player.

It's going to depend on which video player you want this software to work with. You'll have to pick a player, and find out if they have an API you can use to interface with it, then you have to dig...