User blog comment:Xydux/Status Report for 2012/@comment-31027411-20121227204656/@comment-1915803-20121231221502

Well that's disappointing. I'm really surprised that you would not be able to take a screenshot through DVD Player, as the Mac screenshot capability is not directly affiliated with DVD Player. Taking a screenshot is just replicating what you see on the screen at a particular time, regardless of what application is open.