一种MPEG2媒体同步控制算法  

Algorithm of media synchronization for MPEG2

作　　者：吴炜[1] 常义林[1] 

机构地区：[1]西安电子科技大学ISN国家重点实验室,陕西西安710071

出　　处：《系统工程与电子技术》2005年第1期173-176,共4页Systems Engineering and Electronics

基　　金：高等学校博士学科点专项科研基金(20010701006);ISN国家重点实验室基金;华为基金资助课题

摘　　要：针对MPEG2软件解码器,提出了一种媒体同步控制算法。该算法无需调整解码器的本地系统时钟,而是以音频流为主媒体流,视频流为从媒体流,音频的播放速率保持不变,利用基于相同时间基点的媒体单元的播放时间标签,调整视频的播放帧率来实现媒体同步。同步调整后视频的同步比例由调整前的54.84%提高到99.52%,音视频的同步比例由调整前的5.07%提高到98.36%。结果表明,该算法可以实现解码器的媒体同步,满足用户提出的感知服务质量要求。An algorithm of media synchronization for MPEG2 software decoder is proposed. It is unnecessary for the algorithm to regulate the values of local system clock in decoder. With audio as master media stream whose playout rate is unchanged and video as slave stream, the algorithm makes use of presentation time stamp of media units which have a common time base to synchronize the presentation of video sequence with audio sequence. Intra-media synchronization ratio of video increases from 54.84% to 99.52% and inter-media synchronization ratio between audio and video increases from 5.07% to 98.36% after synchronization regulation. The proposed algorithm can achieve media synchronization and meet the requirements of perceptual quality of service.

关 键 词：媒体同步 播放时间标签 感知服务质量 

分 类 号：TN915.01[电子电信—通信与信息系统]