Research Of Audio Synchronizing Algorithm Under Noisy Situation

The 21st century is the era of the network,along with the high speed development and the rapid spread of the Internet,the needs of using network for the transmission of audio information are growing.Emergence of streaming media technology,to some extent,improved the difficult situation of Internet transmitting audio which turn traditional media "push"-style in the past into the audience "pull"-style real-time communication and dissemination.As the streaming media technology to some extent broke the network bandwidth limitations on the transmission of multimedia information,it is widely used in the live webcast,Internet meeting,distance education and enterprise training.In order to better achieve streaming media transmission service,it is always necessary to evaluate the quality of streaming media,but also challenging to the quality evaluation of streaming media audio.This paper mainly discusses the perceptual evaluation of audio quality algorithm and audio synchronization algorithm,and,on the basis of the theory,gives the implementation of audio synchronization algorithm in order to ensure the accuracy of the perceptual evaluation of audio quality algorithm.The ultimate goal of the proposed algorithm is used for the perceptual evaluation of audio quality algorithm,so in the front part of the paper,the perceptual evaluation of audio quality algorithm is studied in detail,including the algorithm flow path,produced parameters during the algorithm and the final output of the algorithm.After studying the perceptual evaluation of audio quality algorithm we found the problem,namely,the perceptual evaluation of audio quality algorithm cannot give the correct audio objective quality evaluation score in case there is a delay,which leads to the main study object of paper-audio synchronization algorithm.I give an effective solution in the main part of the paper.The solution is to use twice envelope and histogram delay estimation method,making cross-correlation between the reference audio and test audio with 3ms and 1ms envelope.Based on twice cross-correlation in the two envelope on each segment,the histogram accurate synchronization was realized and the experimental results were analyzed.Based on the analysis results it showed that short-term energy twice envelope and histogram delay estimation method proposed in this paper can effectively resolve the issues raised above,the delay can be reduced in less than 48 sample points,1ms range which is less than the delay generated by the audio codec in the actual life,meeting the normal requirements.Experiments show that through the alignment of the audio synchronization algorithm,and then through the perceptual evaluation of audio quality algorithm we can obtain the right result.