A digital video scrambling system with variable concealed levels incorporating viewing licenses

In mobile TV with subscription broadcasting systems using wireless communications, streaming-based content services and download-based content services which play back stored content on receivers are being considered. These download-based content services require a function for playing back content in deteriorated video to encourage non-subscribers to purchase content, in addition to a function that allows only subscribers to view content. Therefore, content providers require a digital video scrambling method with variable concealed levels to control the video quality of stored content. We propose a digital video scrambling system with variable concealed levels incorporating viewing licenses. The system can handle H.264/AVC coding content, and the processing load for controlling the concealed level of video is low. We also verify by evaluating video quality and implementation that the proposed system is feasible for actual service.