| 摘要 |
A video delivery system and method which can reduce the amount of data stream to be transmitted without damaging a reproduced image when a screen is partially concealed in paid digital broadcasting. A video signal transmitter comprises a shield processing means for concealing an input video signal such that a part of each frame screen included in the input video signal presents a predetermined pattern, a first compression encoding means for applying compression encoding to the concealed video signal at a high compression ratio, a subtracting means for extracting a differential signal between the compression encoded video signal and the input video signal, a second compression encoding means for applying compression encoding to the differential signal at a low compression ratio, and an encrypting means for applying predetermined encryption to an output signal from the second compression encoding means, wherein the encrypted signal is multiplexed on an output signal from the first compression encoding means, and the multiplexed signal is transmitted. |
