基于DSP平台的机载高清视频编码器设计与实现  

Design and Implementation of Airborne High Definition Video Encoder Based on DSP Platform

作　　者：刘荣科[1] 胡伟[1] 高杨[1] 周游[1] 

机构地区：[1]北京航空航天大学电子信息工程学院,北京100191

出　　处：《航空学报》2011年第3期507-514,共8页Acta Aeronautica et Astronautica Sinica

基　　金：中央高校基本科研业务费专项资金(YWF-10-01-B24)~~

摘　　要：针对无人机(UVA)航拍对高清视频的需求,设计并实现了基于数字信号处理器(DSP)平台的MPEG-4高清视频编码器,具有体积小、功耗低和可靠性高的特点。根据DSP片内资源设计了存储器分配方案,优化了编码过程中的数据流传输,降低了数据访问对编码速度的影响。针对视频编码算法中复杂度较高的部分,采用了基于预测的运动估计,减少了匹配搜索时间;提出了改进的变长编码方案,大幅提高了编码速度;提出了一种提前判断全零系数块的充分条件,有效减少了离散余弦变换(DCT)和量化计算。实验结果表明,该编码器对720P格式(1 280pixel×720pixel分辨率)视频的编码速度在20帧/s以上,并且峰值信噪比(PSNR)高于35dB,具有良好的画面质量和较低的码率。To enhance the capacity of video capturing and ground reconnaissance of an unmanned aerial vehicle（UAV）,an efficient MPEG-4 high definition video encoder is designed and implemented on a digital signal processor（DSP） platform,which is characterized by small volume,low power consumption and high reliability.Firstly,the data flow scheme of video encoding is optimized by allocating the on-chip memory of the DSP reasonably,which reduces the impact of data access on encoding speed.Secondly,prediction-based motion estimation is adopted to accelerate the search of matching blocks.Furthermore,optimized variable length coding and predicting all-zero coefficient blocks are proposed to improve coding speed and reduce discrete cosine transformation（DCT） and quantization computation respectively.Experimental results show that,for the video sequence with 720P（1 280 pixel×720 pixel resolution） format,the optimized encoder can achieve an encoding speed of over 20 frame/s,and the peak signal to noise ratio（PSNR） is higher than 35 dB,with satisfactory visual quality and relatively low bit rate.

关 键 词：数字信号处理器 MPEG-4 视频信号处理 实时系统 高清 优化 

分 类 号：V243[航空宇航科学与技术—飞行器设计] TN919.8[电子电信—通信与信息系统]