Audio Transmission And Frame Buffer Optimization Based On Mirrorlink

With the development of automobile electronic and communication technology, the vehicle information platform has become the new trend of modern vehicle development.At the same time,mobile phones developed to set information services and entertainment services in the smart phone.How to make users,whihout touch or look at phone screen and phone keys, to control the mobile phone only use physical buttons in car platform or voice commands has become a hot issue in recent years.In this context,some well-known international mobile phone manufacturers and automobile manufactures jointly launched a "car networking" standard-MirrorLink to specification the connection between mobile phone and vehicle system.This paper first introduces the development background of MirrorLink products,and then focus on the MirrorLink protocol and related techniques.On this basis, I analyses the existing problems in the process of MirrorLink product development, then perfect audio transmission module and device discovery module function,enhance the transmission efficiency of the frame buffer. Existing problems in the process of product research and development mainly includes:(1)The System audio in android mobile phone can’t transmission to vehicle platform in real-time.(2) The rate of frame buffer update is low and audio is not in sync with the picture.(3)The interaction between the equipments has low flexibility and the interconnection between the application’s client and server is complex.To solve those problems, the paper has took depth research and study on MirrorLink 1.01 protocol, it includes:To solve the problem(1),I put forward how to obtain the android system’s audio,design and implementation of audio transmission module to make the server’s system audio can transmission to the client in real-time.To solve the problem(2),I analysis the reason why frame update has low rate,and put forward the YUV compression algorithm,improve the frame update rate through compressing frame data.Make the audio and frame playback synchronization using the timestamp.To solve the problem(3),I take depth study of the equipment interconnected and interactive information form.On this basis, I design and implementation of UPnP modle which the connection between equipment’s informationis stored in a XML,and the automatic connection between the client and server through UPnP broadcast.Finally, after solution of the above problems,this paper gives the functional test results,performational test results and standards conformance test results,then analyzes the results.Last we put an outlook on the next step.