Quote:
Originally Posted by MHSTech
Tonight I went to play a DVD on our video system. As I was playing it, I noticed that the audio was a second or so ahead of the video. What causes this? What can be done to fix it? We have a VP-25xl presentation switcher from Kramer, and they it gets sent to a distribution amplifier (also a Kramer) to all of the TVs and projector.
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This is quite common in video rigs. First, play the DVD on a player that is directly connected to a NTSC (not computer) monitor. Make sure that it is not an issue with the DVD. Sometimes, DVDs that come from "pro-amateurs" have some sync issues so rule that out first.
Commonly, the video delay is caused by the time it takes to process the NTSC signal into hires, scaled video. Depending on the speed of the internal processor, it can vary from model to model. The way it seems that this one works is to process anything that is not highres before it sends it to the output. Sorry but there is no way around this. It is doing lots of things here that need to be done technically. If you want a more detailed example, let me know and I can get into the grit of the matter.
Normally, we put audio delays on the devices and slow them down just a bit. Usually this is no more then the 1/30 of a second delay caused but the box. If it is more, then there may be some other issues.
kw