Based Rdclient Voip Network Audio System Design And Realization

This thesis describes how to develop a set of remote connections environment audio transmission system based on RDclient client software which developed by team. Will Linux client audio transmission via remote desktop connections to Windows server and played. And RDclient the original windows can have a server to a linux client audio transmission of audio transmission channels combined to achieve two-way audio transmission function remote connection. And this system can be applied to a remote teaching, remote medical treatment, etc.This thesis can be generally divided into two end system, respectively is Linux client systems and Windows server system, subdivided into five modules. Respectively is Linux audio acquisition module, audio data compression module, TCP audio transmission module, audio data unpack data decoding module, Windows audio playback module. Make full use of various techniques, VoIP field realized the audio transmission pursuit of low delay, continuity good, take up the network bandwidth small and so on target. Starting from the study of the application of a VoIP, introduces the basic principle and delay VoIP the main sex and related factors, and the realization of the safety of considered VoIP, objective by describing the current VoIP application status, RDclient agreement followed a detailed description and analysis in this thesis, through the analysis RDclient that currently there are defects in the need to be improved in order to realize the project requirement. Then began to design and implement audio linux client acquisition and compression coding, which RDclient main fork child process plug-in out of the start of a detailed description of the sound card program, and the ITU-T defines the various compression algorithm such as G.711 , G.723, G.729, etc., analyzed, and ultimately come to the use of G.711 a-law compression algorithm, and in the acquisition of audio and compressed between the use of multi-threading technology, between father and son and then describes in detail the process by Audio data communication channels. Then design and realized based on TCP protocol audio transmission system, in design process fully use VoIP transmission related technologies, avoid packet disorder, delay increase etc method. Finally, design and implement server-side windows and play the audio decompression code, describes the process windows sound card programming and broadcast operations in the decoding and decompression between the use of multi-threading technology and double-buffering technology to achieve the continuity of audio playback and trying to reduce the delay. Linux and windows at both ends to grab the audio data packet test results show that after the data compression and transmission is almost no change in the system to achieve perfect.Finally, summarized, this thesis describes the function and innovation of realization, and points out that the next step improved where the train of thought and direction.