MultiStage: A MINMAX Bit Allocation Algorithm for Video Coders

Most bit allocation algorithms for video are geared toward optimizing the average frame distortion. However, video sequences optimized this way may exhibit sudden changes in distortion, or "flicker," which can significantly affect the perceived quality of the sequence. An alternative approach is to minimize the maximum frame distortion, which aims to produce a constant-quality sequence, thus avoiding the flicker problem. In this work, we present a new algorithm for constant-quality video, called MultiStage. We first show how MultiStage works for an embedded bit plane coder, and we then demonstrate that it can be applied to traditional quantization-based coders, such as H.263 and H.264, in conjunction with a novel single-frame block-level rate-distortion optimization algorithm based on multiple-choice knapsack. We show that MultiStage achieves very good results, both in terms of maximum distortion and average distortion