File Size (I'm a little confused)

[shawnpm]

Hello. I have a question. I'm new and I did search so I apologize if it has been covered and I missed it.



Nature of the problem:

I have a video (00:43:49) that I'm breaking down into roughly 10 minute segments and each segment can not be any larger than 50 - 52 MB. What's so weird to me is that I can create these 10:00 +/- minute segments but they can drastically differ in file size.

For example, I just finished creating three videos (video clips do contain audio).

The first video runs for 00:10:46, bit rate is at 709kbps, dimensions are 320 x 240 and the file size is 27.7 MB.

The second video is 00:10:53 w/709kbps, 320 x 240 and its size is 55.0 MB

The third video is 00:10:24 w/709kbps, 320 x 240 and its size is 49.1 MB



What's going on here? How come one file is only 7 seconds longer yet it's 27.3 MB larger?



Properties of your source files (format, file size, where did you get it?):

Source file was originally one big dvr-ms file from XP Media Center - I used dvrmsToolbox to convert it to .mpg. The dvr-ms file was 858 MB @ 00:43:49. Once converted it is 767 MB @ 00:43:49.


What devices are involved and their mode of connection?:

Captured video from TV Tuner card on Toshiba P25-S670


Project Settings:

.wmv


To create my 10 minute file I do the following:

Click Share
Click Create Video File
Click WMV
Click WMV Broadband (320 x 240, 30 fps)

I'm using VideoStudio 11

I don't understand what I could have done to caused such a drastic file size difference over a mere few seconds.

Is it possible to have VideoStudio split up a file into as many segments as needed to per an entered MB value?

Thank you for any advice/feedback

[sjj1805]

There are various codecs (CO-mpression DEC-compression) in existence and I will not pretend to know all the ins and outs of them.

Could I ask if the video with the smaller file size contains video that is predominantly the same - lets say you took some video of the clouds in the sky. Frame by frame very little will have changed and so the codec probably does something like:
Instead of recording 1,000 bytes of data saying "This is blue" it records one or two bytes of data saying "The next 1,000 items are blue"

Compare that video to the longer one - does it involve a lot of movement and lots of color?

This would at least explain the large difference in file sizes despite the similar duration.