A PC-based personal video recorder (PVR) system enables recordation of
video content on a general-purpose computer in a way that the computer is
unable to perceptively display the recorded content, but is able to
playback and distribute the content to a decoder box (e.g., set-top box)
for display on a television. In one implementation, the general-purpose
computer is equipped with a personal video recorder (PVR) card having a
video tuner, a network connection, and scrambling capabilities. The PVR
card is configured to receive video content and produce compressed
digital video. The card scrambles the video content and stores it in the
computer's memory. The scrambled video content is in a form that cannot
be perceptibly displayed by the computer. During playback, the PVR card
retrieves the scrambled video content from the memory, descrambles it,
and outputs the video content to the decoder box for playback on the
television.