lebo i tu pise :
http://jaw.iinet.net.au/stuff/makevideo.html

When capturing video, the device is feeding frames to Virtualdub. Depending on how quick your device is, how quick your computer is, you might not get a frame exactly on the dot of your selected frame rate. By the way, the frame rate is selected by clicking on the fps button on the bottom on the screen. Your webcam might only be capable of 16fps - so what happens when you tell it 25fps? Basically, every couple of frames it will double up, two frames in a row that are exactly the same.

There are three ways of dealing with this - firstly, do nothing and hopefully the PC and the webcam will operate perfectly and neither will miss a beat. However if they occasionally miss a beat then the video and audio will come out of sync. Terrible! The second is to adjust the audio by speeding up and slowing down according to the video rate. Yuck! I dunno about you but the sound of the guitar is more important that an occasional dropped frame. The third is to adjust the video to the audio by dropping excess frames or inserting extra frames as necessary. It would be better if the devices could keep up with each other, this option is the next best bet.

http://jaw.iinet.net.au/stuff/makevideo08.png

...proste VirtualDub ma tu funkciu ako obist to hardwarove casovanie, ale tak asi to nieje dokonale ??