Target files over 4GB, lip sync issues???

So I've got some HD material I want to convert over to Xvid to save space. I want to retain as much of the original quality as possible so a number of the movies ideally would be over 4GB. The problem I have run in to is that when the files goes over 4GB lip sync is lost as playback surpasses this location. From all of the searching I have done it sounds like "avi" files have a maximum size of 4GB by spec. Is this true? I have seen posts of people claiming to have no problems with their encodes over 4GB. If I don't want to have the file split should I go Matroska? Do I need to use Gordian Knot to do mkv or should I be able to still use Auto Gordian Knot to do the video then mux to mkv with something like AVIMuxGUI to mux in the AC3 audio? Or would AGK still be broken at the VirtuaDub step (I've done some video only encodes with AGK with a target file size over 4GB and then muxed the AC3 in to mkv with Avimuxgui and still have the lip sync issues towards the end of the file)?

Your audio sync problem is probably not related to the size of the AVI file, per se, but it might be related to your player. Try a different player, and see if the problem remains. For more on AVI and FAT32 file size limitations, see:

Good link, thanks. I should have described my environment a little more. I am using NTFS and desired playback is in MCE. I sometimes will test playback with ZP right after encoding as well. Since it looks the file size is not the problem (although it is still odd that encodes that are a tick under 4GB don't lose sync) I guess it may be the audio decoder I am using (AC3Filter).

...I guess it may be the audio decoder I am using (AC3Filter).... I didn't find anything regarding ac3filter limitations thru search. But if you transcode the audio to another format, does the problem go away?