Implementation of opportunistic data on a statistical multiplexing encoder

摘要

A method and apparatus for providing an opportunistic data capability for an existing statistical multiplexing encoder platform, such as a multi-channel video data encoder. An Opportunistic Data Processor (ODP) is provided as a plug-in card or an external device that can be interfaced with an existing multi-channel encoder. The ODP communicates with a Quantization Level Processor (QLP) and Packet Multiplexer (PM) in the multi-channel encoder as if it was just another channel encoder. The ODP implements a special rate control scheme by encoding data and sending it to the PM only when a global Quantization Level (QL) indicates that spare bandwidth is available. Spare bandwidth is assumed to be available when the global QL is less than a threshold value. Moreover, the OPD sends a bandwidth need parameter to the QLP, as do the other channel encoders. However, the ODP's need parameter is scaled by a function of the global QL to attenuate its actual bandwidth need as the global QL increases to provide smooth variations in the ODP's encoded data rate.