Perian is an excellent, free, and open source QuickTime component. VLC is also often referred to by its original name, VideoLAN Client.

Probably the easiest way to play AVI and DivX files on Mac OS X is to download and install the freeware VLC Media Player for OS X. While none of these methods are foolproof and some AVI files still refuse to play, one of these methods will usually work. We have found that the following four methods will enable viewing most AVI files that do not play in QuickTime. QuickTime Player 7 is installed in the Macintosh HD > Applications > Utilities folder. Likewise, if you attempt to open a media file that requires QuickTime Player 7, you are offered the opportunity to install it. If you elect not to install QuickTime Player 7, it can be installed later. If you have an existing QuickTime Pro key, QuickTime Player 7 is installed automatically and Pro functionality is available in QuickTime Player 7. Nevertheless, Snow Leopard includes QuickTime Player 7 as an optional install: QuickTime X will invoke QuickTime Player 7 to play videos supported by the latter or by QuickTime Player 7 components. Under Mac OS X 10.6 Snow Leopard®, QuickTime Player aka QuickTime X does not support third-party components, i.e.

QuickTime does not include native DivX support, even though QuickTime 6 and later support the ISO Standard MPEG-4 media compression format and DivX is based on the MPEG-4 standard. To further confuse the issue, many DivX®-encoded files carry the. In particular, the Indeo ® CODEC, popular for video compression on PCs, has not been ported to Mac OS X. However, most, if not all AVI playback issues arise with movies that have been compressed using CODECs (Compressor - Decompressor) that are unavailable for QuickTime in Mac OS X. AVI was originally called Video for Windows ® (VFW) and QuickTime supports the VFW format. AVI is a media container very similar to QuickTime, but with a unique data format. There has been confusion over AVI files since QuickTime ® added support for such. This chapter from our book Troubleshooting Mac® OS X discusses why some Audio Video Interleaved (AVI) multimedia files do not play in QuickTime and provides methods for playing AVIs on Mac OS X.

How to play an mpeg 4 file on a mac