Title :
Rate-distortion analysis for H.264/AVC video coding and its application to rate control
Author :
Ma, Siwei ; Gao, Wen ; Lu, Yan
Author_Institution :
Digital Media Lab., Chinese Acad. of Sci., Beijing, China
Abstract :
In this paper, an efficient rate-control scheme for H.264/AVC video encoding is proposed. The redesign of the quantization scheme in H.264/AVC results in that the relationship between the quantization parameter and the true quantization stepsize is no longer linear. Based on this observation, we propose a new rate-distortion (R-D) model by utilizing the true quantization stepsize and then develop an improved rate-control scheme for the H.264/AVC encoder based on this new R-D model. In general, the current R-D optimization (RDO) mode-selection scheme in H.264/AVC test model is difficult for rate control, because rate control usually requires a predetermined set of motion vectors and coding modes to select the quantization parameter, whereas the RDO does in the different order and requires a predetermined quantization parameter to select motion vectors and coding modes. To tackle this problem, we develop a complexity-adjustable rate-control scheme based on the proposed R-D model. Briefly, the proposed scheme is a one-pass process at frame level and a partial two-pass process at macroblock level. Since the number of macroblocks with the two-pass processing can be controlled by an encoder parameter, the fully one-pass implementation is a subset of the proposed algorithm. An additional topic discussed in this paper is about video buffering. Since a hypothetical reference decoder (HRD) has been defined in H.264/AVC to guarantee that the buffers never overflow or underflow, the more accurate rate-allocation schemes are proposed to satisfy these requirements of HRD.
Keywords :
quantisation (signal); rate distortion theory; telecommunication control; variable rate codes; video coding; H.264/AVC video coding; hypothetical reference decoder; motion vectors; quantization scheme; rate control; rate distortion analysis; rate distortion optimization mode-selection scheme; rate-allocation schemes; video buffering; Automatic voltage control; Decoding; Encoding; Motion control; Process control; Quantization; Rate-distortion; Testing; Video coding; Video compression; H.264/AVC; hypothetical reference decoder (HRD); rate control; rate-distortion optimization (RDO); video coding;
Journal_Title :
Circuits and Systems for Video Technology, IEEE Transactions on
DOI :
10.1109/TCSVT.2005.857300