| 摘要 |
PURPOSE: A method for enciphering and decoding a multimedia contents file based on a frame is provided to analyze a frame structure of the frame-based multimedia contents file, to separately extract a frame header and frame data and encipher only the frame data, so as to maintain a structure of the multimedia contents file. CONSTITUTION: Only multimedia data existing in a frame excluding a frame header are enciphered. The enciphered multimedia data are decoded. In the step of decoding the enciphered multimedia data, cipher information is extracted(41) and stored in a specific memory area. An optional frame is read(42). Whether the read frame is the last frame is checked(43). If so, the steps are ended, and if not, whether the corresponding frame is enciphered is checked(44). If so, a decoding operation is performed using the cipher information stored in the specific memory area(45) to extract decoded frame data(46). And the extracted data are reproduced(47).
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