Research And Implementation Of HLS Player Based On Streaming Media Adaptive Strategy

In recent years,the HLS streaming media protocol has been widely used in IPTV system gradually.Its main advantages are high bandwidth utilization and strong network adaptability.However,compared with the traditional streaming media server,the HLS server does not provide the function of I-frame slicing,meanwhile,the version of the HLS server is not higher enough in the current IPTV system's environment,which cause the following defects in the client:(1)In the operation of positioning playback,when locating a time within the TS segment to play,we usually choose the start of this segment or next segment for playback,resulting in a large time-offset when playing,if we directly choose the locating time to play,there will likely produce a blurred screen as well.(2)Can not support fast forward and rewind playback,it can only take the form of dragging progress bar to play.To solve these problems above,an adaptive strategy based on HLS streaming media is proposed.That is,not only does it adapt to the server's changes in version of HLS protocol,but also performs key frame detection of video stream in the client.Besides,the implementations of related algorithms are added.Thus to cut down dependence on the server for the client,and achieve precise positioning play and fast forward rewind playback.Furthermore,a HLS player based on this adaptive strategy is designed and implemented.The implementation of HLS protocol and the related sub-modules in player are described in detail in this thesis.According to the current IPTV system's environment and the local test environment,positioning playing and fast forward rewind playback are tested which are the two scenarios for adaptive strategy application.Experimental results show that the proposed adaptive technology greatly improves the accuracy of positioning playing-time,and the fast forward and rewind playback of HLS video stream are realized as well.Thereby to ensure the integrity of operations in playback-control,and improve user experience.Undoubtedly,the realization of these functions will have a great promotion on the popularization of HLS protocol in IPTV system.