The Design And Research Of Embedded Video Acquisition System Based On ARM11 And H.264

With the rapid development of the “smart city” construction, the video acquisition system has been widely applied and developed. As an important part in the video system, embedded video capturing and video processing has become a hot-spot research. In such situations as video conference and video teaching,a higher video acquisition speed, image quality, video storage and so on is in demand. And without any processing, the capturing of video data must be accompanied by a large number of redundant data. It’ll produce serious obstacles for people to obtain and deal with the video information. Thus removing redundant information is a very important step in video acquisition system. Meanwhile the embedded video system is highly valued with its characteristics of low cost, intelligent and miniaturization. Therefore at the aim of improving the performance of embedded video acquisition system,this article introduces a video capture system that adopts S3C6410 as hardware platform, Linux operation system as software platform and H. 264 as compressed encoding.The designed system uses the S3C6410 processor as the central controller and data processing center. Its main body structure is composed of ZC301 P camera and LCD. And it has a support of Linux3.11.0 embedded operating system. Consequently, it realizes high-speed data acquisition,display and processing tasks. It implements the video acquisition by calling the V4L2 API, and completes the real-time video image acquisition, compression, decoding, display and playback by combing with H. 264 coding,FFmpeg decoding library and SDL library.The article first gives a detailed analysis and introduction of the ARM and its peripheral hardware. Then it presents the software design of this system, which includes system software and application software.The system software consists of VMware,Linux operating system,cross-compilation setup and configuration, the kernel tailoring and transplanting,the u-boot production and transplanting and Linux root file system modification and transplanting.The application software can be divided intovideo capturing module, video compression encoding module, video decoding module and video display module. It uses modular design idea and writes the function module according to the function order. And the article also makes a thorough analysis on H. 264 video acquisition algorithm. Although the original H. 264 or other compression algorithm could eliminate redundant information as well, an improved rate-distortion algorithm is proposed in this article.At last, We carried out a test and an analysis on the system,the result shows that the designed system can realize the acquisition and compressed coding of a real-time video of 30 frames per second with a 320 x240 pixel resolution while guarantee the quality of the original image. With the rate distortion improved,H. 264 raises the coding efficiency to a certain degree, makes the memory storage of the video information smaller, forms clear images, keeps real-time well and makes the system stable and reliable. The designed system has great practical value in the field of video capturing and processing. The study result has reached the intended target.