基于单元尺度的自适应码率控制算法

随着信息技术的快速发展,压缩编码已成为多媒体存储和传输领域的研究热点。针对视频压缩的编码效率问题,ITU-T与ISO/IEC两大标准组织于2003年联手推出了H.264/AVC视频编码标准。为了能够在目标带宽上有效地传输视频,就必须合理地控制码流的波动强度,以使其尽可能地接近目标带宽。其中码率控制虽然不是标准中的一部分,但由于其一直在视频编码标准的发展过程中占有举足轻重的地位,为此,针对H.264/AVC编码的视频序列码率控制问题,在JVT-G012算法的基础上,提出了一种基于STGS图的自适应地选择基本单元大小的码率控制算法。该算法在编码时产生的码率波动总是与G012算法产生的最小码率波动相当。而且具有较小的运算复杂度,易于实时实现。

A Basic unit Size Based Adaptive Rate Control Algorithm

With the rapid development of information technology,compress coding has become a heated topic in the field of multimedia storage and transmission.Aiming at the coding efficiency of video compression,ITU-T and ISO/IEC jointly developed a new video coding standard named H.264/AVC in 2003.In order to transmit video efficiently on certain bandwidth,the rate fluctuation should be controlled to make it as close to the target bandwidth as possible.Although rate-control is not a part of the standard,it has been playing an important role in the standard all the time.For this purpose,on the basis of JVT-G012 algorithm,a new rate-control algorithm based on Spatial-Temporal Gradient Scale(STGS) image is presented for H.264/AVC coding to select the size of basic-unit adaptively.The rate fluctuation resulted from the proposed algorithm is always close to the best case of JVT-G012 algorithm.Moreover,for the low computational complexity,the proposed algorithm is easy to implement in real time applications.