You might have noticed that some of your videos no longer have a Finder preview in Mavericks. Macworld’s Chris Breen discovered that Apple has deprecated many of its older codecs in favor of the iOS-compatible H.264 and MPEG-4. To watch older video files, you must convert them with QuickTime X, install Apple’s professional codecs (if you bought Final Cut Pro, Motion, or Compressor), or use a more capable app like QuickTime 7 Pro or MPlayerX. follow link
How to Make an iPhone Screenshot
Want to take a screenshot of something on your iPhone or iPod touch? Press the Home button and Power button briefly at the same time, and an image of your screen will be saved to the Photos app (and will sync with iPhoto when you next connect). Don't hold the buttons too long or your device will either power down or reboot.
- ExtraBITS for 4 November 2013 (04 Nov 13)
Why Your Videos Won’t Preview in OS X 10.9 Mavericks