I am working on a simple video writer program. However, when I use the I420 codec (which so far has been the only one that works with my computer), the output video file is quite large. It's about 80MB for 30 sec. I wanted to work on a program which records at least 10 minutes of video and at this rate it will end up being 1.6GB. How is it that some movies which are 1:30 are less than a GB and is there any way to further 'compress' the video file output?