Adaptive Distortion-Based Intra-Rate Estimation for H.264/AVC Rate Control

Rate distortion of Intra-frame (I-frame) plays a significant role in controlling video quality for H.264/AVC. This letter presents an adaptive distortion-based Intra-rate estimation (ADZE) algorithm for H.264/AVC rate control. In this algorithm, a new rate control model is established based on the distortion by taking image complexity, buffer status, and scene change into consideration. After adaptively updating this model, our proposed algorithm is capable of providing more accurate estimation for the quantization step (Qstep) of the I-frame than other conventional methods. Experimental results show that the proposed method can significantly improve video quality (up to 1.62 dB average PSNR performance), while achieving an accurate output bit rate. More importantly, it provides a more stable visual quality which is a result of keeping the buffer occupancy steadier than other existing rate control algorithms.