Apologies if this is the wrong forum. It seems to be a little in between the different categories.

I wanted to record an encrypted video stream last night so I used a screen recorder. The quality wasn’t too bad though there were some brief skips and stutters along the way. Mostly it seemed like one or two frames were being dropped when it happened but it didn’t noticeably affect the picture or sound. I left the recording running overnight and it seemed to be okay.

When I played it back both video and audio quality were fairly good but the audio was badly out of sync. When I tried to correct it I discovered that the sync problem wasn’t consistent. Throughout the entire two-hour recording it keeps shifting every five minutes or so by variable amounts. I spent the entire day trying to repair it by hand because I really want this recording but it is a hopeless task. I don’t have professional editing equipment and trying to match sound to lip movement every few minutes is sheer torture, at least on the editor I am using.

I have two questions about this. First, is there any magical software that can somehow go through the MP4 file and resynchronise the audio to the video? Second, can anyone shed any light on why this happened in the first place? Would it have to do with my connection, which is wireless RBI on 3g? It is not very fast and the speed can jump up and down a lot, though it usually works well enough for streaming. Or is this the fault of my recorder software? I am using Any Video Recorder, which has some quirks, but I like it because it is very straightforward to set and use and it produces MP4 files rather than WMV or other unhandy formats. Any insights would be greatly appreciated.