基于X.264的嵌入式无线视频传输单元及其优化

The Embedded Wireless Video Transmission Unit Based on Optimization X. 264

针对无线视频传输中因视频编码产生的图像清晰度差、实时性弱等问题,设计了一种基于X.264的嵌入式无线视频传输单元。该无线视频传输单元基于Linux操作系统,以S3C2440A处理器为核心,利用Linux内核提供的视频数据采集接口V4L2控制摄像头采集视频,之后经过X.264编码的视频流通过Wi Fi无线网络和RTP流媒体传输协议传送至PC客户端显示。针对X.264编码中UMH运动估计算法的不足,采用3×3搜索模板和动态搜索窗口策略,改进的UMH算法有效降低了算法的编码时间和运动估计时间,提高了编码过程的实时性。实验表明,在不影响图像质量和码率的前提下,应用优化算法的无线视频传输单元,运动估计时间效率最大提高32.9%,编码时间效率最大提高9.18%。

Aimed at the poor image clarity and weak real - time performance during the video transmission due to the limitation of the conventional video coding technology, a remote wireless video transmission unit based on X. 264 standard was designed. With the S3C2440A microprocessor as the core chip and Linux as the operating system and using the video data acquisition interface (V4L2), the camera captures the video signal, which is then X. 264 encoded and transmitted to the PC client though the wireless network and RTt' streaming media protocol. The 3 * 3 pattern and dynamic search window has been proposed to solve the lack of the UMH motion estimation algorithm in the X. 264 standard. The experimental results show that the improved UMH algorithm can greatly decrease the motion estimation time by 32.9% and improve the encoding time by 9.18% while maintaining the image quality and encoding rate.