QuickTime 7.5 finally added feature that all Final Cut Pro (FCP) users will enjoy: JKL transport controls. Just like in FCP, the J, K, and L keys control the playback of your video: J is backward, K is stop, and L is forward.
Tapping the J or L keys multiple times increases the speed of playback. Holding J+K or K+L plays back in slow motion.
Mac OS X Hints
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