A novel rate predictor based on quantized DCT indices and its rate control mechanism

摘要

In this paper, we propose a model-based rate predictor, which is based on the indices of quantized DCT coefficients. The proposed rate predictor, which can characterize the detailed changes during encoding processing, provides a more precise rate estimation than the traditional rate control methods, which are based on pixel variance. Based on the models of the proposed rate predictor, the optimal quantization step size can be easily obtained from a given bit-rate constrain. Finally, the rate control mechanism based on the precise rate predictor is then developed. Realized in MPEG-4 verify model (VM), the simulation results show that the proposed algorithm achieves superior rate control ability and improves PSNR of the reconstructed video signal at the same time.