ALGORITHMS FOR DETERMINING BITRATE FOR A STATISTICAL MULTIPLEXING SYSTEM TO ENSURE STREAM ALIGNMENT FROM ENCODERS TO THE MULTIPLEXER

摘要

A statistical multiplexer (statmux) system for encoding and multiplexing multiple channels of digital television data is provided that limits dropped bits due to misalignment of bit rate allocations to the encoders. Without such a system, if for example an encoder is allotted 0 bits during a first time period and 20 kilobits during a second time period, if the encoder jumps ahead from the first period to the second time period allocation, the 20 kilobits could be output during the 0 bit output allocation time period. This can cause buffer overflow downstream if other encoders are outputting at their maximum rate. To limit such misalignment, a maximum percentage increase of an encoder's bitrate allocation is set from time period to time period based on a formula to prevent bits from being dropped when misalignment occurs.