A Scene Complexity Adaptive Intra-frame Rate Control for Video Coding

Rate distortion of Intra-Frame (I-frame) plays a significant role in controlling video quality. Aiming at the deficiency of I-frame rate control of H.264, this paper presents a novel I-frame rate estimation method for H.264 rate control. Firstly, Rate-Complexity-Qstep (RCQ) model of I-frame was gotten by curve fitting, secondly, the information of encoded frames was used to update I-frame weight relative to P-frame, and a reasonable target bits was allocated for I-frame, finally, I-frame Qstep was calculated under the target bits by RCQ model. Experimental results show that the proposed method obtains more accurate I-frame output bit rate and more steady PSNR fluctuation compared with H.264 standard algorithm.