| 摘要 |
PROBLEM TO BE SOLVED: To mange access to pay-per-view and pay channels, etc., being excellent in serviceability without preparing advance announcement and without managing preview time. SOLUTION: In this video distribution system, a low quality video stream and an enciphered high quality video stream having the same video contents are simultaneously distributed, the low quality video stream can be viewed as it is by any terminal, and meanwhile, the high quality video stream has to be decoded by a key to be viewed. |
