A gradient-based rate control algorithm with applications to MPEG video

In this paper, we present a rate control algorithm for MPEG video. The goal is to minimize the distortion while keeping the change in distortion between consecutive frames small. We formulate this goal as a constrained optimization problem and find a solution using an iterative gradient search method. To reduce the computation cost, we propose a model based on spline curves to approximate the rate distortion functions which also takes into account the frame dependencies. Simulations on short video sequences show that, at the same bit rate and buffer constraint, our technique generates output sequences with smaller and more stable mean square error than other approaches, while maintaining strictly constant bit rate for every group of pictures, at the expense of higher computation cost.