| With the rapid development of computer technology, image compressiontechnology and network communication technology, the digital television technologyhas made considerable progress, and promoted the research and development ofmultifunctional intelligent multimedia terminal system. Digital television integratedmachines, which begin to play a vital role in everyday life, have gradually become thecore part of home entertainment systems, and bring people the high quality audio-visualenjoyment. Multimedia synchronization technology plays an important role, and theaudio and video synchronization is the research priority among priorities.Firstly, a detailed analysis of the advantages and disadvantages of existing audioand video synchronization methods and techniques is given in this paper. Some primaryfactors which influence synchronization are analyzed, too. After that, the originalrequirements and design requirements of this scheme are provided. The testingstandards of the synchronization performance are described from two aspects:subjective and objective. Afterwards, based on the hardware and software of digitalvideo processing chip X11V100which is researched and developed by HuaweiTechnologies Hisilicon technologies limited, the processing framework of audio andvideo synchronization is proposed.Then the audio and video synchronization scheme is elaborately designed andrealized. On the basis of global time axis system, the synchronization is reached throughcomparing the time stamp of audio and video. According to the specific project, threemain improvements has made in the thesis:(1) two kinds of time information, audioPTS and PCR which can be dynamically switched, are set as the time references;(2)strict interval method is used to process data hierarchically based the out of step’sdegree of audio and video;(3) phased synchronization is proposed, pre-synchronizationand synchronization are set, fast synchronization and slow synchronization are carriedout to follow the physical truth.Finally, the testing scheme is taken out based on the laboratory environment, andlots of board tests are completed. The results of data analysis show that the scheme canbetter realize the synchronization of audio and video, and the subjective effect is alsoobvious. |
PDF Full Text Request