Why the frame number wrong??

[hkalex]

Hi all,

Here is an image

http://www.geocities.com/yeungtt/matlab1.jpg

The upper part information is shown by VirtualDub.
You see there are 2248 frames.

However, the lower part information is shown by Matlab by using command aviinfo(). You see there are only 1705 frames.

Not only this file, I have many files with over 1705 frames and Matlab could only read from 1st frame to 1075th frame. What's happen?

Thank you very much.

Regards,
Alex