基于PSTN传输信道的视频编码器码率控制

Rate Control Scheme of the Video Encoder on the PSTN Channel

码率控制是在低带宽信道上传输低延迟、高质量视频的关键技术之一.根据基于PSTN信道的远程视频监控应用需求,提出一种甚低码率控制策略,通过为视频编码器增加I帧码率控制,改进P帧的位率控制算法,以及引入二阶率失真模型,较好地解决了甚低带宽下视频编码器的码率控制问题.实验结果表明,算法降低了编码缓冲区延迟同时提高了重建图像的质量.

Rate control is one of critical technologies that are used to transmit low-delay and high-quality images on the channel of very low bandwidth. According to the application demand of remote surveillance system based on PSTN, this paper proposed a rate control scheme of very low bandwidth. The video coder gained good performance at even low bandwidth by adding I-frame rate control and improved P-frame control based on the quadratic rate distortion model. Experiments show that this scheme reduces the delay of encoder buffer greatly, and improves the quality of reconstructed images as well.