QuickTime Player, the video player and editing tool bundled with the Mac for ages, received a fairly major overhaul when it turned into QuickTime Player X. While it became free and lost the need to upgrade to a Pro version, it also lost out on a lot of really nice professional features that QuickTime Player 7 had. Perhaps most missed from QuickTime Player 7 is the excellent A/V tools panel, which allows users to adjust the video brightness, color, contrast, tint, playback speed, audio volume, audio balance, bass, treble, pitch shift, and playback.
Fortunately, for Mac users running any somewhat modern version of OS X, whether it’s Snow Leopard, OS X Lion, OS X Mountain Lion, OS X Mavericks, and even OS X Yosemite (!), you can actually still install and run the older QuickTime Player 7 client, and have it sit right alongside QuickTime Player X without incident.