An Efficient Two-Pass VBR Encoding Algorithm for H.264

In this paper, an efficient two-pass variable-bit-rate (VBR) algorithm is proposed for H.264/AVC video encoding. In the first pass, CBR coding is employed to gather the encoding statistics of the input sequences. On the basis of the obtained statistics information, such as encoding complexity, PSNR, macroblock distributions of each coding type and etc, an offline processing is applied on these data to detect scene cuts, accurately allocate target bits and determine each frame´s quantization parameter based on rate-distortion model, and then the second pass coding is performed. Simulation results show that the proposed algorithm can not only provide consistent visual quality perceptually, but also satisfy a long-term constant average bit rate constraint