| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an improved selective encryption method for H.264 bit streams that ensures standard compliance. <P>SOLUTION: This invention relates to selective data encryption of a file, in particular an H.264/MPEG-4 AVC data stream 300. If a first unit 310 in the data stream 300 is to be encrypted, it is encrypted and the encryption is put into a further unit 410, preferably in the data stream 300. A substitution unit 415 is generated and put in the place of the first unit 310, and if necessary, at least one header value is taken from the first unit 310 for use in the substitution unit 415. A decryptor 840 receives an encrypted data stream 400, extracts and decrypts (750) the further unit 410, and replaces the substitution unit 415 with a regenerated first unit. <P>COPYRIGHT: (C)2013,JPO&INPIT |
