Description of ScreenCapper program at Mac Shareware: ScreenCapper allows you to generate screenshots of your video files easily. It supports a lot of different formats (avi, mov, mkv and more...). It can generate single screenshots, a series of multiple screenshots, or a customizable screenshot grid.

ScreenCapper allows you to generate screenshots of your video files easily. It supports a lot of different formats (avi, mov, mkv and more...). It can generate single screenshots, a series of multiple screenshots, or a customizable screenshot grid.

Features:

Works with a lot of formats. If QuickTime can open it, ScreenCapper can!
Very easy to use.
Can generate single screenshots, a series of multiple screenshots or a customizable screenshot grids.
Pick your start time and end time and any amount of screencaps (up to 200) and you're good to go!
Let's you pick the size of the output images.

ScreenCapper is a free to try software. You can free download and try it for an evaluation period.