Incorrect video record lengths

[Google Code Exporter]

What steps will reproduce the problem?
1. When manually recording from two separate USB webcams on the same computer

What is the expected output? What do you see instead?
I am trying to record a six-minute video of a scientific experiment. The length 
of the video is critical. We though the GUI mentions having recorded a 6min. 
video, the actual recorded video is always shorter (~5-10 second shorter). This 
would be acceptable if the shorter lenght was consistent - but the video lenght 
seems to vary significantly between two records?

What version of the product are you using? On what operating system?
Downloaded the latest version of the ispy. I am using a Winxp

Please provide any additional information below.

I have been testing a lot of combinations - like changing the recording FPS 
between 10-30, reducing/increasing bitrate of the recorded video but to no 
success.

Any help would be greatly appreciated.

Thanks
Anand.

Original issue reported on code.google.com by [e-mail] on 16 Mar 2013 at 7:43

[Google Code Exporter]

I'm having the same problems - I want to record continuous video broken into 
30sec sections but the length varies by 2/3 secs every time.

Ger

Original comment by [e-mail] on 11 Apr 2013 at 9:24