Research And Implementation Of Key Technology Of HLS Extensible Streaming Media System

With the rapid development of Internet technology and the continuous enrichment of network applications,streaming media technology has been widely concerned and used.Unlike traditional media transmission and playback,streaming media users can quickly and easily access the desired content through the terminal.The research on the key technologies such as the collection,processing,storage,scheduling and transmission of streaming media data has become a hot spot in the field of audio and video.Mobile Internet as a traditional extension of the Internet to flourish,based on HTTP streaming technology is also widely deployed and applied,Apple's HLS technology is one of the representative projects.Research and implementation based on HLS efficient streaming media distribution technology is the main work of this paper.Aiming at the diversity of coding standard,the instability of communication link state and the terminal heterogeneity in streaming media distribution,the video coding principle,standard and transcoding technology are analyzed,and the video multi-bit rate conversion based on open source library FFmpeg is proposed.Code scheme,the program can provide users with differentiated,personalized,adaptive transcoding services.In a large streaming media distribution system,the cluster service mode is usually used,due to the need for the release of video files for multi-rate transcoding and multiple copies of distributed storage led to a large number of redundant copy files.How to manage these copy files effectively becomes the key problem to improve the service capability and service quality of distribution system.In this paper,the author chooses the copy object,the number of copies control,the copy of the three aspects of the study.Algorithm 1 is a copy number control algorithm.The algorithm makes a dynamic addition and subtraction of the number of replicas to improve the utilization rate of the system resources by reasonable evaluation of the copy and deletion costs.Algorithm 2 is a copy object selection algorithm.The algorithm calculates the file support degree to represent the popularity of the file,and then uses the replica prefetch algorithm RPA to replicate the popular streaming media files in the future and reduce the user access delay by distributing the replicas of these replica files.Algorithm 3 is a copy placement algorithm.The algorithm uses a multi-index load evaluation method to calculate the real load of the service node for the heterogeneous problem of the cluster service node,and realizes the optimal placement of the copy in the cluster environment according to the calculated load.The effectiveness of the above algorithm is verified by simulation experiments.Finally,this paper builds a HLS-based streaming media distribution system,which verifies the feasibility and effectiveness of the multi-rate transcoding scheme.The system has a basic service function such as video upload,slice,transcoding and user management,video distribution and other video-on-demand website.