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高清晰度电视的传输流采用了MPEG 2系统层标准ISO/IEC 13818 1。阐述了高清晰度电视 (HDTV)传送流中时间信息码在视频和音频同步中的作用 ,分析了信源解码器中视频和音频同步的原理。就实际芯片中系统时钟的恢复、视频和音频的跳帧等机制进行了讨论 ,并提出了一种非锁相异步全数字视音频同步实现方案。该方案采用了直接置数法恢复系统时钟 ,滞后跳帧法实现视频与系统时钟的同步 ,数字锁相法控制音频与系统时钟同步。最后 ,对视频帧率和音频PCM时钟的偏差等问题作了进一步的探讨
The transport stream for high-definition television uses the MPEG 2 system layer standard ISO / IEC 13818-1. The role of time information code in video and audio synchronization in high definition television (HDTV) transport stream is expounded. The principle of video and audio synchronization in source decoder is analyzed. The actual chip system clock recovery, video and audio frame skipping and other mechanisms are discussed, and proposed a non-phase-locked asynchronous digital AV synchronization implementation. The scheme adopts the direct set number method to restore the system clock, lags the frame skip method to realize the synchronization between the video and the system clock, and the digital phase lock method controls the audio to synchronize with the system clock. Finally, the video frame rate and audio PCM clock deviation and other issues made further discussion