Research Of Video Compression On Micro-UAV

Application and development of information technology in military war hasbecome the holy grail of the modern military war, and the miniature UAV imageinvestigation which plays a very important role in the modern military war becomes ahot research. In this case, to meet the objective requirements of the design of imagetransmission system which is independent of network and computer, the the microUAV image compression part of entire transmission system is main emphasis of thispaper. Analyzing the existing micro-UAV wireless image transmission system,according to the requirements of real-time compression and transmission, and theresearch of video compression and DSP development status, the H.264compressionalgorithm encoder scheme based on DSP platform is confirmed. This scheme can beapplied to the military, as well as civilian applications in video surveillance, medicalinsurance, emergency.In this paper, H.264video compression algorithm codec framework and keytechnologies is analyzed. H.264has characteristics of high compression ratio,high-quality, low bit rate, but at the expense of complex algorithms which affects thecoding efficiency. H.264implementation version has three: JM, X264,T264, bycomparison to all,JM as the official test source code which focuses on academicresearch and has high coding complexity is not practical; T264is written by nationalorganization and runs much faster than JM, but it is imperfect; X264combines therespective advantages of JM and T264,therefore,X264is selected as algorithmprototype.High speed of DSP can meet the requirements for real-time, TMS320DM6446ischosen as hardware platform, but the the X264algorithm source code which isdeveloped in VC environment, needs to migrate to the DSP, the main migration workincludes Code cutting, allocation of memory space as well as aspects modificationaccording to the differences of the compiler.Successful migrated code needs to be optimized in order to ultimately meet therequirements of real-time processing. In this paper, according the study of expense offunction of the X264code, optimization works are as follows: encoder options、motion estimation algorithm as well as inline functions. On the basis of further research and comparative experiments of Motion estimation algorithm, the diamondsearch algorithm is selected and optimizated. The experimental result shows thatcoding efficiency is significantly improved without losing the quality of the vedio.