These codecs are add-ons to QuickTime, that allow playing videos in various formats that are not natively supported.
Perian supports basically all non-native formats, except for Ogg and Windows Media. This includes MPEG 4, H.264, DivX, and FLV.
Note that Perian has decided to stop supporting their project. The source code will be released to GitHub or Google Code, but it has yet to be determined who will pick up support going forward.
Download the latest image file, open the DMG file, and double-click on the
Perian.prefPane file. Select to install for all users. All the default configuration options should be fine.
Flip4Mac is available from Microsoft ( Windows Media Components for QuickTime) or Telestream ( Flip4Mac). Both seem to be the same, including the most recent versions. Be sure to get the latest version for Mountain Lion.
Download the latest image file, open the DMG file, and run the Flip4Mac installer. The image also contains an installer for Microsoft Silverlight. We'd recommend that you NOT install Silverlight.
Note that Flip4Mac installs a FlipPlayer application in addition to the codecs.
Xiph QuickTime Components ( XiphQT) allows playing Xiph formats (Ogg Theora) in QuickTime. It also enables playing Ogg Vorbis and FLAC audio files in iTunes.
Download the latest image file, open the DMG file, and copy the
XiphQt.component file to