基于H．265编解码高清视频传输系统

摘要

In order to solve the problems of the bandwidth pressure and the time delay when transmittting HD video in real time, this paper proposed a new method to improve the situation of the time delay and bandwidth pressure in the ar⁃ea of the real-time transmission of HD video. First, the transmission system proposed used Hi3516A processor to decode HD video. Then, the dedicated streaming media server based on Boost:asio was designed. In the end, the system ren⁃dered the decoded video based on DirectX. According to experiments, the delay time of the transmission system was a⁃bout 120ms, when the video of 1080P eccoded by H.265 transmitted in the condition of 25 fps and the rate of 2M. At the same time, the PSNR of decoded video by H.265 / HEVC was almost equal to the PSNR of decoded video by H.264 /AVC in double bandwidth under the same quality of source video in the condition of capturing the SD video and HD vid⁃eo. But the PSNR of decoded video by H.265 / HEVC was better than the PSNR of decoded video by H.264 / AVC in double bandwidth under the same quality of source video,when the system transmitted the video of 1 080P.%为解决高清视频的实时传输将带来带宽压力的增加和时延的增长等，基于H．265编解码提出一种新的高清视频传输系统设计方法来改善上述情况。系统首先采用Hi3516A处理器对高清视频进行H．265硬编码，然后运用Boost：asio库进行专用流媒体服务器设计，最后基于 DirectX进行渲染显示方案设计。经系统实验验证，文中系统通过对高清1080P视频在25 fps帧率以及2 M码流传输情况下经H．265编解码后，系统传输时延约为120 ms。同时在普通高清720P和标清480i视频采集条件下，H．265相对于H．264在传输码率减半时解码后图像的PSNR值与经H．264编解码解码后图像的PSNR值基本相同。但在高清1080P视频采集条件下，H．265编解码在1 M码率传输时解码后图像的PSNR值明显优于H．264编解码在2 M码率传输时解码后图像的PSNR值。