Optimal bit allocation for low bit rate video streaming applications

Current rate control schemes in video coding standards do not have efficient frame-level bit allocation because of the inherent constraints in real-time encoding. In this paper, we assume an offline video encoding environment and proposed a rate control scheme based on optimal bit allocation for low bit rate streaming applications. Specifically, we apply a ρ-domain rate-distortion (R-D) model, originally applied at macroblock (MB) level, to frame-level. Based on this frame-level R-D model and a two-pass encoding method, we are able to allocate bits among video frames in an optimal way so that video sequences can be coded at low bit rate with an improved quality. Experimental results demonstrate the proposed scheme is able to achieve not only noticeable reduction in average distortion but also a more consistent and smoother visual quality.