A novel linear source model and a unified rate control algorithm for H.263/MPEG-2/MPEG-4

Let ρ be the percentage of zeros among the quantized transform coefficients. We discover that, in any typical video coding system, there is always a strictly linear relationship between ρ and the actual coding bit rate R. This linearity leads to a novel and unified source model for different types of source data and different coding systems, such as H.263, MPEG-2, and MPEG-4. The proposed linear source model is much simpler, but much more accurate than other source models reported in the literature. Based on this source model, a unified rate control algorithm is proposed for the above three video coding systems. Despite its extreme simplicity, the proposed algorithm outperforms other rate control algorithms by providing more accurate and robust rate control