| 摘要 |
<p>A scrambling and descrambling method that includes reading of original PID and TSC bits in the PID and TSC fields of a packet header of an MPEG2 stream which is at least partially scrambled. A temporary PID may be written in a PID field in place of the original PID, and may be a function of the original PID value and TSC bits according to a correspondence table of an original PID and TSC bits with the temporary PIDs. The value zero may be written in the TSC field in place of the original value, and scrambling of the stream with modified fields may occur. Applications include the satellite transmission of partially scrambled MPEG2 digital signals.</p> |
