Audio (i.e. speech) and video (i.e. lips) out of sync

I’ve noticed in certain movies I have downloaded the sound, such as speech, and actions, such as lips moving, will be out-of-sync. For example, I have the movie “No Country For Old Men” in .avi format and the sound and actions are perfectly in-sync. However, I have the movie “Iron Man” in .mkv format and I noticed the the speech is off just a split-second from the people’s lips moving. I was just wondering if this is a problem with my computer or with the movie itself?
Not all .mkv formatted movies have this problem. I have “Super Bad” in .mkv format and the sound and actions seem to be in-sync. This leads me to believe it is a problem with how the uploader ripped the movies, encoded them, or whatever. My sound card driver and video driver are completely up-to-date. I have a GeForce3 Ti 200 video card and a Soundblaster Audigy sound card. Any help or information is very much appreciated.
Thanks in advance.
Edit: By the way, I use the latest KMPlayer and have the latest Combined Community Codec Pack. I have also tested the movies with Windows Media Player and Media Player Classic and seem to have the same problem.
Answer #1
You could try installing the CoreAVC professional codecs and then set KMplayer to use them as shown here…
http://www.kmplayer.com/forums/showthread.php?t=3571
Here’s a link to the codecs..
http://www.google.com?t=1713607&highlight=
I use them with Zoom player too and it seems to work well..
I tried converting an .mkv to DVD with Convertxtodvd….that was a different story…the synch was out then..darn.
Answer #2
Wow, thank you very much, ! With the information you have provided, it seems I have solved my A/V sync problem. Woot! I downloaded CoreAVC, which I hadn’t even heard of until you suggested it, and enabled it as an external video decoder for KMPlayer. I then enabled “SuperSpeed” mode, thanks to that thread you provided, and bingo-bango, it worked! You’re a life-saver! Thank you so very much.
Edit: By the way, this thread could be very useful to any other person having A/V sync problems when playing movies.