Data rate management of compressed digital video has been a technically challenging task since it is vitally important in various audio-visual telecommunication services to achieve an effective video data rate (video rate) control scheme. It has a large influence on video quality and traffic congestion in B-ISDN networks. Up to date, this issue has been treated mainly from the teletraffic control point of view, i.e. by modelling congestion control via network protocols. Relatively less attention has been focused on video rate management in the source coding side. In this chapter we consider that it is more efficient and less costly to control video rate at the video source than handling network congestion (or overloading) due to an extremely large quantity of incoming variable bit rate (VBR) video traffic. Thus this chapter investigates effective rate control algorithms for video encoders. Considering the non-stationary nature of video rate derived from scene variations (i.e. the wide band nature of digital video), we adopted two nonlinear approaches; radial basis function (RBF) estimation using a neural network-based approach and fuzzy logic control as a nonlinear feedback control. The RBF network scheme is primarily discussed and then the fuzzy logic-based scheme is compared to it. The performance is evaluated using the criterion how effectively video rate is maintained within a specified range or at a value while achieving satisfactory video quality.
展开▼
