I havn't tried it on Windows, but there are binaries for Windows Mplayer Mplayer for Windows.

As with ffmpeg, you can capture frames with

mplayer tv:// -tv driver=v4l2:width=640:height=480:device=/dev/video0 
+-frames 10 -vo jpeg
[download]

also see ztk-v4l-video-bloger/recorder for how to capture video with mplayer in a Tk window. It uses V4l, but updating it to V4l2 would be easy.