Statistical multiplexer with primary and standby encoders and multiplexers which can differentiate good and faulty units sharing a dynamic address

摘要

A statistical multiplexer for multiple video signal bit streams (Program 1-4) includes primary video encoders (120:1-4) and back up video encoders (130:1-2) kept on hot standby to take over when a primary encoder fails, via router (170). The video encoders feed multiplexers (140,160) which operate in an active and hot standby arrangement. A rate controller (150) oversees the system. The statistical multiplexer uses dynamic identification, such that when a back up encoder/multiplexer takes over from a faulty primary it assumes its identity (eg Encoder 1, Multiplexer 1). In order to avoid conflicts arising when a faulty encoder continues to transmit data the backup encoder output includes a flag, and flagged signals will be given precedence over other signals with the same identifier. Similarly, for the multiplexers a character in the output signal is incremented each time they assume primary responsibilities, and signals included the highest value will take precedence with downstream devices.