Research And Implementation Of High Definition Video Streaming Capture Recording And Playing System

The development of Internet and multimedia technology leads to the development of the recording and playing technologies, which is widely used in the quality curriculum, remote education and other areas of open class. Currently recording and playing system is mainly in the form of three-part-separated screen, which can render video camera, computer screen image and index directory. Now more popular elite open class, MOOC and quality courses and other educational platforms mostly is in the form of video playback. In order to adapt to the existing form of teaching network, show the only one video of HD camcorder video, computer images and so on, and meet the demands of portable recording and playing, it is important to develop recording and playing system which mainly is software processing.The paper designs and completes a HD video streaming capture recording and playing system which is projected to provide customers with more scenes of the video display, also these scenes mainly are the video of high-definition cameras, computer monitor pictures of teachers end,and PIP images of the first two scenes together synthesis. By switching among the three scenes, only one kind of video image,which is compressed,encoded and presented to the user in the form of live demand, is ultimately outputed. The paper recommends the research status of recording and playing system, and then introduces the technologies and knowledges which are used in the process of system development, and then describes the functional modules to be achieved from the architectural level, and then describes the design and realization of specific functional modules. These modules are: the console module, audio and video capture module, teachers end image acquisition module, PIP module, video switching modules, and audio and video compression encoding module.Console module uses MFC framework provided for system interface design; audio and video capture module uses DirectShow technology to achieve HD video and audio capture; teachers end image acquisition module uses Socket technique to acquire teacher end screen images, and open source library of the libjpeg is used to convert JPEG images into BMP images; PIP module implements image scaling and PIP function; video switching module switches video images among HD camera video, computer screen images and PIP pictures,and then RGB24 images are con-verted into YUV420 images; audio and video compression coding module uses open-source tools, x264, to compress video stream into H.264 format, and uses FAAC audio encoder to make audio converted AAC format.In the process of system development the author deep solves a number of key issues. By using timer, solving the audio and video out-of-step issues of the MP4 video file, caused by frame rate unstability; solving the situation that playback time of AAC audio is longer than the recording time alongwith the growth of the recording time; and soving parameter configuration issues in the process of real-time compression encoding by x264.Currently, the system has been deployed and tested stably, which can be portable and meet the demands. This paper also proposes the content which the system should improve.