Level: Beginner

Make movies play automatically
Automatically playing a movie when it’s opened is one that we took for granted until it disappeared. Until Apple gets around to adding it to the Preferences dialog box, thankfully there’s
a Terminal command to switch it on.
Close QuickTime X before entering it.
Open the Terminal ; located in applications-Utilities. Or type terminal in spotlight (located in upper right hand corner). When terminal window opens, type the following commands:
defaults write com.apple.QuickTimePlayerX MGPlayMovieOnOpen 1

Hide QuickTime’s TitleBar
Use this Terminal command to turn it off:

defaults write com.apple.QuickTimePlayerX MGCinematicWindowDebugForceNoTitlebar -boolean TRUE

Stay in full-screen mode
All good movie players should have an option to remain in full-screen mode if another application comes to the foreground. That way, you can quickly read a new email or
talk to someone with iChat applications, while allowing a movie to take up most of the screen, rather than sticking it in a small corner of the screen.
So does that mean that QuickTime X isn’t a good movie player? Not at all. Apple simply disabled the capability and failed to provide a clear way to toggle the setting. Nevertheless, it’s still there, ready and waiting for you to turn it on in Terminal. Quit QuickTime and enter this command:

defaults write com.apple.QuickTimePlayerX MGFullScreenExitOnAppSwitch -boolean NO


Tips: commands must be typed in same line without pressing ENTER. After writing the full command in same line, press ENTER.