Joint rate control for coding multiple video objects

This paper describes an algorithm which achieves a constant bit rate when coding multiple video objects. This implementation is based on the current MPEG-4 video verification model. Each object maintains its own set of parameters. With these parameters an initial target estimate is made for each object. Based on the buffer fullness, the total target is adjusted and then distributed proportional to the size, motion, and variance of each object. Appropriate quantization parameters can be calculated for each video object based on the new individual targets and second order model parameters. This algorithm assures that the target bit rate is achieved for low latency video coding.