An invention for measuring, maintaining and correcting synchronization
between signals which suffer varying relative delays during transmission
and/or storage is shown. The preferred embodiment of the invention finds
particular use in measuring the relative delay between multiple audio
signals and an associated video signal of a television type program which
is compressed via MPEG or other compression for a transmission and/or
storage system. The invention marks the video signal at a time when a
particular event in the associated audio occurs. The mark is carried with
the video throughout the video processing. After processing the same event
in the audio is again identified, the mark in the video identified, the
two being compared to determine the timing difference therebetween.
