Variance based bit allocation algorithm to improve the TM5 rate control model of MPEG-2

This paper proposes an algorithmic modification in the rate control test model 5 (TM5) of MPEG-2 video encoder. A drawback of the TM5 model is that it allocates the same number of bits to all macroblocks in a picture (April 2003) (M. Sipitca, August 1996). A more appropriate distribution of the available bits can be done based on the complexity of the macroblocks. For this, an algorithm to classify the macroblocks based on their complexity is presented. Next, using this classification, a bit allocation algorithm is developed. The adaptation process of the quantization parameter is modified accordingly. By this approach, the overall PSNR quality of the encoded video increases by about 0.2 to 0.3 dB as compared to TM5 model.