It can be quite annoying (and funny at times) when you are watching a video and the audio and video are not synchronized. This is an occurence that is very prevalent in most Kung Fu movies where the voice comes a second or so after the lips start moving. This occurs because the audio and video are out of phase.

The expression out of phase simply means that they are not in unison. When objects are out of phase, one leads while the other folloows, and vice-versa. To eliminate this problem, a phase adjuster is normally put at the final output stage of the video so as to ensure synchronization. It compensates for the video or audio being ahead or behind and puts them in phase.

To better explain phasing, think of two race cars. If they both set off at the same time and at the same speed, they would be side by side, or synchronized. But if car 1 starts accelerating, it will move ahead of car 2, thus they would no longer be in phase. Car 1 would now be leading car 2 while car 2 is said to be lagging. To get them back in phase, car 1 would either have to decelerate and allow car 2 to catch it up OR car 2 would have to speed up to catch car 1. Once they are both side by side, they would now have to travel at the same speed to stay synchronized.

So, phasing is not a hard topic to swallow. It really is quite easy. And if you should ever see your local TV station showing non-synchronous audio and video, give them a call and ask them to adjust their phase mechanism.