MPEG-4 video object-based rate allocation with variable temporal rates

This paper describes a bit allocation algorithm to achieve a constant bit rate when coding multiple video objects (MVOs), while improving the rate-distortion (R-D) performance over the reference method for MPEG-4 object-based rate control. In object-based coding, bit allocation is performed at the object level and temporal rates of different objects may vary. In this paper, we deal with these two issues. We pay particular attention to maintenance of buffer occupancy levels and propose a new method for spatiotemporal trade-offs for object-based coding. The proposed algorithm is able to successfully achieve the target bit rate, effectively code arbitrarily-shaped MVOs with different temporal rates, and maintain a stable buffer level.