CONTENT-BASED RATE CONTROL SCHEME FOR VERY-LOW BIT-RATE VIDEO CODING

In the applications of very low bit-rate video coding, the quality of the encoded pictures always suffers from serious degradation due to li mited bandwidth. The quantization levels, in typical video coding syst ems, are adjusted depending only on the fullness of the output buffer while the content of the video is not taken into account. This explain s why the picture quality varies saliently in very low bit-rate applic ations. In this paper, a content-based bit-rate control scheme is prop osed. In this approach, the content of the coded picture is first anal yzed to find the main attributes of each macroblock. The attributes of the macroblocks are then consulted while adjusting the quantization l evels. In other words, the quantization levels are adjusted not only d epending on the fullness of the output buffer but also on the content of the coded material. Simulation results show that the perceptual qua lity of the coded pictures, by using the proposed method, is better wh ile comparing with the traditional non-content-based approach.