Design And Implementation Of Embedded Audio And Video Codec Interface Board

In recent years,digital image and video,which are the representatives of visual media,are enriching our daily life.On one hand,various video applications including intelligent video surveillence are continously popularized.One the other hand,the percentage that video data occupies the network bandwidth and bitstream is also continously increasing.There are plenty of literatures about the design of audio/video capturing card,and also many products in the market.However,there is still no unified models and specifications for audio/video capturing interface card.That is,users should determine the technical specifications in terms of the application scenarios and environment,so as to choose or develop audio/video capturing interface card with different model and specifications.First,the hardware circuit is designed and implemented for the embeded audio /video codec interface card,which includes not only video capturing module,audio capturing module,FPGA module,video encoding module and audio encoding module,but also peripheral circuits including power,timing and memory.The hardware system is made up of two high performance Hisilicon ARM processors Hi3531 and one Xilinx Spartan-6 series' FPGA chip XC6SLX45 T.Hi3531 is to encode video and audio following H.264/AVC and G.711,respectively.The encoded auio/video files are output via duplex-interface RAM.FPGA send the timing data via PCIE interface to Hi3531 processor,and implement a duplex-interface RAM interface.The hardware circuit has been produced by PCB routing and wiring.Second,the software for interface card is implemented,which is built on the basis of embedded Linux operating system and Hisilicon media precessing platform(MPP).Preliminary experiment is also conducted.Embedded Linux system has the advantages of real-time performance and hareward-independent,which is suitable for this interface card.The MPP provided by Hisilicon semiconductor can avoid some complex instruction system which is closely related with the c hip hardware(including the registor operation)and support rapid development of application program.Users can directly call the interface functions via the MPP program interface(MPI)for the capturing and encoding of audio/video data.The designed interface card meets the majority of performance indexes of project technical agreement.It is also verified by practical video encoding and decoding tests,and desirable visual quality has been achieved.