Rate Control Algorithm For H.264/AVC

H.264/AVC is a high performance video coding technology, and it is drafted by the Joint Video Team (JVT). H.264/AVC has the following characteristics:low stream, high-quality images, fault-tolerant capability and high network adaptability, which makes it to become the most competitive standard in a variety of video applications.JVT-G012 is the main rate control algorithm for H.264. This paper does deep researches on the frame layer bit allocation, the encoded frame information, and scene change detection and treatment respectively, and we propose an improved rate control algorithm for H.264/AVC in the following three aspects:Aming at the bit allocation in frame layer is too uniform, and it has not considered the difference between the frames in the video sequence. This paper adopts the image complexity factor to measure the complexity of the current frame, and allocates the bits based on the image complexity factor. The experimental results show that our algorithm not only achieves more accurate rate control, but also improves the value of peak signal to noise ratio (PSNR).We take the encoded frame information into account. This paper adjusts the quantization parameter of the current frame according to the information of encoded frames. With the use of the complexity factor, our algorithm achieves more accurate rate control and a much better visual quality.Because of the fixed length structure for group of pictures (GOP), it can not effectively deal with the scene change in video sequences, leading to serious decline in the image quality. In order to effectively solve this problem, an adaptive rate control algorithm is proposed. Experimental results show that the proposed method can more accurately control the bit-rate, and it also can smooth video and maintain a lower degree of encoder buffer occupancy.