Research On Key Technologies Of Digital Video And Audio Information Transmission In IP Network

Currently,digital video and audio technology,which playing an important role in contemporary people's work and life,is a research focus in the booming Internet field.The rise of distance education,smart TV and live broadcast industry has accelerated the update and iteration of digital technology for video and audio.However,the implementation of current streaming media system is mostly based on General Personal Computer platform.In comparison,the embedded device,which has the advantages of simple and efficient,flexible and customizable,is widely used in the field of streaming media with high real-time requirements.Therefore,this article designs and implements a set of complete digital video and audio information transmission system on the embedded platform.The hardware platform of this system equipped with ARM9,can transmit the transport stream(TS)of digital TV front-end equipment to the client player through multiple streaming media protocols.It completes the IP network adaptation of the television program stream.There are two innovations in this research topic:Firstly,the embedded implementation of digital video and audio information transmission protocol extends the streaming media protocol to the application scenarios of embedded devices.Secondly,using a variety of streaming protocols to transmit the TS stream makes each digital video and audio transmission protocol suitable for use in the digital television field.The digital video and audio information transmission system designed in this paper supports a variety of common transmission protocols for content distribution of TS stream,including UDP(User Datagram Protocol),RTP(Real-time Transport Protocol),RTSP(Real Time Streaming Protocol),RTMP(Real Time Messaging Protocol)and HLS(HTTP Live Streaming).By combining the actual application scenarios,a simplified implementation of the RTMP protocol is presented to improve the packetization efficiency of the protocol.The RTMP protocol,only the video and audio data in the FLV format is applied originally,for the server pushing strategy is adopted.Since the HLS protocol needs to retain the fragmentation,a memory-based HLS distribution scheme is proposed to solve the problem of insufficient Flash for embedded devices.The experiment proves that the system works well and can meet the streaming media transmission service of embedded platforms such as digital TV front-end equipment.