Abstract:

In this paper, we propose a new rate control algorithm for the H.264 frame layer. A novel RQ (RateQuantization) model for Iframes is established based on rate, spatial complexity and buffer status. The target bits of an I frame is decided by the relation between the number of bits generated for the I frame and P frames of the previous GOP, and the QPi(Quantization Parameter for I frame) is determined adaptively. The target bits of a P frame is modified according to the HOD (Histogram of Difference) and its relative position. The experimental results show that the proposed algorithm can increase the average PSNR (Peak Signal-to-Noise Ratio) of the reconstructed video, and depress the PSNR fluctuations. At the same time, some skipped frames are avoided.

Key words: H.264;rate control;frame layer;intraframe;interframe