Buffer-constrained R-D model-based rate control for H.264/AVC
Most existing R-D model based rate control schemes are not applicable in H.264/AVC due to the unique features of H.264/AVC, for example, the QP-dependent rate distortion optimization (RDO); the large number of bits (header bits) used for encoding the header information (except DCT coefficients) of a macroblock (MB); the huge number of zero-coefficient MBs. We present an R-D model based rate control scheme for H.264/AVC. A pre-analysis is conducted for R-D estimation. A rate model is developed to estimate the coefficient bits and the header bits separately. A frame-level bit allocation scheme is proposed. In comparison with JM6.1e, our scheme not only evidently improves the PSNR of decoded video (an average 0.54 dB PSNR gain is achieved for 7 sequences tested) but also meets the target bit rates accurately (within 2%).