Hi, I wrote a program which input video stream into a video object in Matlab. Here is the code:
vidObj = videoinput('winvideo');
Then i preview the video by:
preview(vidObj);
I capture the video file using:
capturedData = getsnapshot(vidObj);
getsnapshot() only returens one frame. But i need to save the hole video in avi format. I have planned to have a capture button in GUI which will have a start and end duration. For the entire duration the video will be saved. How can i do this. Please help!

 

Lots of converters out there.
http://www.ojosoft.com/how-to-convert/vob-to-avi-converter.html

 

Without additional information about just what you're doing, languages, etc. it's tough to provide specific advice but as a general comment, have a peak at the book "Encyclopedia of Graphics File Formats" (it's available on amazon for cheap, cheap, cheap) if you're looking for the structure of the AVI file format. It's an old text but really quite robust and still pretty useful. You'll want the one by James D. Murray & William VanRyper. You'll also get a feel for some early video compression techniques, still images, PNG files, tiff, gif, jpeg, etc. All round, a pretty good desk reference.

Hope this helps.