MP4Cam2AVI is a MP4/MOV/M2TS to AVI repackaging tool for digital photo-video cameras, it makes their clips editable in VirtualDub, MovieMaker and other AVI editors. Also it can combine (join) multiple clips from camera into a single AVI movie, preserving audio/video sync.
No video recompression (by default), no quality loss, fast operation (5-20x realtime). No installation needed - just download, unzip and run mp4cam2avi.exe.
Today we could say avi format being considered as output format is obsolete. All the video editors, web browsers and mobile devices can play the subset of mp4 format. So I prefer another converter, FFMPEG Windows 1 Click (Intel-compiled). It accepts video in any format and generate mp4 file playable by all the browsers and devices. Also It does all the conversion in exactly one mouse click. You can easily find it by Google or search engine built-in here.
I had some issues with merging 4 really big MP4 files (about 1GB each) without audio (AAC) and video conversion into one 4GB (MAX) .avi. But everything else is just perfect ;-). Many small sources into one .AVI was 20-times faster than "PLAY"!