From Mac Guides
DVD Player is a free application provided by Apple as part of Mac OS X. DVD Player allows the playback of DVDs on your Mac. When a previously played disk is inserted it offers to begin playback where you left off.
Apple's DVD Player software, unlike most OEM-bundled software, is tied to the computer's optical drive. Though computer optical drives are not usually region specific, the DVD Player software is. The software only lets the user change regions four times after its initial setting. After that, the user must send his or her computer into Apple for them to reset the region encoding for a fee.
When the DVD Player Software is running you are prevented from taking screenshots, even if the DVD Window is hidden behind another active window.
It is possible to take screenshots while DVD Player is running in a window using the Terminal. Simply enter this command into a Terminal window:
screencapture -i ~/Desktop/screenshot.png
Or one may take a screenshot of the complete screen and crop after:
VLC Media Player software is a region free DVD player and multi-format audio and video player.