Design And Implementation Of Online Learning System Client Based On IOS

With the development of internet technology,traditional teaching methods can not meet the needs of teachers and students and the demand of online education involved in live technology increased significantly.This paper studies and implements the “Online education + live” learning system based on the iOS.With this learning system,the users can watch videos,read study materials and record the time of learning at any time on the iOS devices.Furthermore,the teachers can achieve the live teaching broadcast on the mobile phone through this teaching system,and the students can also interact with their teachers in real time when they watch the live teaching.This topic uses iOS as a platform.According to the preliminary research and theoretical analysis,the paper puts forward the system demand analysis firstly.Then several major functions are achieved according to requirements analysis.The functions achieved in this paper include implementing the classroom resource rendering module by using the Auto Layout technology,implementing records and statistics of learning time according to the learning activities,implementing a video player based on FFmpeg and implementing dynamic page display module based on HTML5 technology.During the process of live broadcast,the function modules include audio and video compression coding,video stream processing,RTMP protocol pushing are implemented.It is important to note that various techniques such as memory management,multi-thread technology,database technology and network communications are employed in the process of implementing the functional modules stated above.After finishing the basic functions of the system,this paper puts forward four technical optimization plan.Taking the characteristics of multiple courses and many pictures in the system into consideration,the memory reuse mechanism for large amount of data loading is designed to reduce the memory occupation.Based on the underlying Runtime mechanism of iOS,a high performance dictionary conversion model is implemented.The design of image caching mechanism and the improvement of LRU algorithm is finished to reduce traffic loss in picture browsing.The bit rate of plug-flow can be dynamically adjust with the network bandwidth,which can reduce lag arising in the live broadcast.Finally,unit test,function test and performance test are finished respectively after implementing the basic function of the system.The test results show that the functional modules in the system works properly and the performance of this app is good.In addition,the system implemented in this paper can be obtained from Apple Store now and it has finished three versions of iteration so far.