Analysis of the H.264 advanced video coding standard and an associated rate control scheme

bstract. An encoded video bitstream is composed of two main omponents: the coefficient bits representing the discrete cosine ransform coefficients, and the header bits representing the header nformation (e.g., motion vectors, prediction modes, etc.). Compared ith previous video standards, the H.264 Advanced Video Coding AVC) standard has some unique features: (1) the header bits take p a considerable portion of the encoded bitstream; (2) the header its vary significantly across macroblocks (MBs); and (3) a large umber of MBs are quantized to zero and produce zero coefficient its (zero-coefficient MB). These unique features make most existng rate estimators inaccurate for decision-making processes reated to rate-distortion calculation for rate control. This paper anayzes the characteristics of the H.264/AVC bitstream, and reveals hat both the header bits and the occurrence of the zero-coefficient Bs are strongly related with motion-compensated residues obained by INTER16 16. Therefore, two statistical models are proosed for estimating the header bits and separating the zerooefficient MBs. Based on the proposed models, a rate control cheme is developed for buffer-constrained constant-bit-rate video oding. Experimental results show that the resultant scheme chieves an average of 0.53 dB peak signal-to-noise ratio (PSNR) ain over the original JM6.1e, and less than 2% bit-rate naccuracy. © 2008 SPIE and IS&T. DOI: 10.1117/1.3036181