| With the advent of the information age,the rapid development of streaming media technology and the increasing demand for video services,all of these have led to the application and development of video coding technology.In the fields of video surveillance,radio and television stations,network live broadcasting and so on,the application of video coding system is more and more extensive,and it is gradually changing people's life style and perspective.Nowadays,in the field of live video broadcasting,most of the network live broadcasting platforms can only achieve the "best effort" of live video broadcasting.The performance of video quality is unsatisfactory.The problems of picture carton,interruption,delay and so on are widespread.Real-time coding system is an important part of the solution of network live broadcasting technology.Therefore,it is of great significance to study and design a real-time multi-code rate coding system of high-definition video which can provide high-quality video picture playing smoothly with limited bandwidth.Based on the embedded platform of Linux and H.264 video coding algorithm,combined with streaming media technology,adaptive transmission algorithm and web server technology,this paper realizes the design of real-time multi-code rate coding system for HD video.The encoding system consists of four modules: audio and video signal receiving and decoding module,multi-code rate encoding module,streaming media transmission module and human-computer interaction module.The core work of this paper includes:(1)Analyzing the high definition video coding standards,understanding the coding algorithm framework and the implementation block diagram of coding and decoding,and researching the implementation method of multi-code rate coding.(2)From the point of view of network video live broadcasting application,the function and performance requirements of HD video real-time multi-code rate coding system are analyzed.According to the complexity of the design scheme and the cost of hardware design,the overall design scheme of the system is formulated and the related chips are selected.At the same time,the system is divided into modules using the concept of hierarchical design.(3)Designing and implementing each module of the system.(4)Functional testing and performance analysis of the real-time multi-bit rate coding system for HD video are carried out,and the test results are analyzed.The actual test results show that the high-definition video real-time multi-code rate coding system designed in this paper can realize one-way full-definition video signal input,multi-channel different bit rate coding output,multi-channel video streams are packaged and transmitted through the network using RTSP protocol,and the multi-channel video streams are basically synchronized;when the network situation changes,the client broadcasts by enabling adaptive adjustment function.The video screen is fluent and not jammed;the encoding system can be configured by web browser,which is convenient for users to use;and the expected design goals are basically achieved.The real-time multi-bit rate coding system of high definition video designed in this paper has the characteristics of clear hierarchy,clear division of modules,supporting multi-channel multi-bit rate output and high system reliability.At the same time,an adaptive rate adjustment algorithm is introduced,which makes the video picture smooth,high quality and low delay.The research results of this topic have practical application value in the field of high-definition real-time video coding,and have certain reference significance for other types of video coding system design. |
PDF Full Text Request