Nonlinear predictive rate control for constant bit rate MPEG video coders

A nonlinear predictive approach has been employed in MPEG (Moving Picture Experts Group) video transmission in order to improve the rate control performance of the video encoder. A nonlinear prediction and quantisation technique has been applied to the video rate control which employs a transmission buffer for constant bit rate video transmission. A radial basis function (RBF) network has been adopted as a video rate estimator to predict the rate value of a picture in advance of encoding. The quantiser control surfaces based on nonlinear equations, which map both estimated and current buffer occupancies to a suitable quantisation step size, have also been used to achieve quicker responses to dramatic video rate variation. This scheme aims to adequately accommodate non-stationary video in the limited capacity of the buffer. Performance has been evaluated in comparison to the MPEG2 Test Model 5 (TM5) in terms of the buffer occupancy and picture quality.