CCCP on Mac OS X
This page contains all information you will ever need to know regarding CCCP support for the Apple-inclined. There is no such thing as CCCP for Mac OS X, nor will there ever be, but all codecs are implemented in some shape or form on OS X - this page outlines perciely how to use them.
CCCP on Mac OS X
There is no version of CCCP for Mac, and there never will be. This is a rather negative disposition, but the fact of the matter is that it's simply impossible to port.
CCCP is essentially a collection of filters for Microsoft's DirectShow - a technology that allows all video players on your computer share a common library of audio and video decoders, splitters, renderers, and even more. Many popular players implement DirectShow, as opposed to containing their own decoder, thus CCCP fills a much needed position for those who use these DirectShow players. Otherwise, there are self-contained players (e.g, non-DirectShow players, like MPlayer) available for Windows that can play about all files CCCP can, and possibly some more (mostly obscure formats) that CCCP cannot.
Mac OS X has a similar system involving QuickTime, but that's irrelevant. Unlike Windows, with a wide variety of user preferences and players, VLC and MPlayer are the two most overwhelmingly popular players on OS X. These two self-contained players have near or on-par codec support as CCCP when used correctly, thus there is no need for CCCP on the Mac platform.
MPlayer OSX Extended (Good Player)
An up-to-date build of MPlayer designed to work beautifully on Mac OS X. Supports all major formats, including (but by no means limited to) H.264, Xvid, AAC and Vorbis audio, Matroska containers (with the ability to select from multiple audio and/or subtitle tracks on-the-fly) and one of the best ASS softsub implementations that can be found on a Mac. And, unlike VLC and other MPlayer builds, it doesn't require any configuration - it just works. Not to be confused with MPlayer OS X (see below).
NOTE: The first time MPlayer OSX Extended plays something, it will appear to hang for a few seconds before playback begins. This is normal: fontconfig automatically builds a cache when you use MPlayer for the first time. It shouldn't do this more than once.
MPlayer OS X (Bad/Evil)
An ancient build of MPlayer wrapped in an ugly interface with poor settings that won't support many of today's files. Avoid at all costs. Not to be confused with MPlayer OSX Extended (see above).
Perian (Good but handicapped by QuickTime)
Perian is not a player, but a collection of open-source QuickTime plug-ins, and enables viewing of a large number of unsupported formats and containers such as Matroska (but not OGM) in OS X's built-in QuickTime Player (see below). The project is relatively recent and has seen major updates every four to six months, and is perhaps the most promising Mac playback tool. If you're using Mac OS X v10.5 Leopard, Perian also enables Quick Look for its supported formats, so it's worth installing even if you don't use the QuickTime Player.
NOTE: Perian cannot play Windows Media files. If you want native WMV/WMA support in Mac OS X, you'll need to download Flip4Mac's Windows Media Components for QuickTime from http://www.microsoft.com/windows/windowsmedia/player/wmcomponents.mspx.
QuickTime Player (Acceptable (with Perian installed))
The built-in media player on Mac OS X. On its own, it's pretty useless; most popular containers and video formats are left unsupported. Perian (see above) can fix this. But even with Perian installed, QuickTime will take a long time to load MKV files and there doesn't seem to be any support for switching between multiple subtitle tracks. Install Perian by all means — it'll work with most modern video files, and you'll get the aforementioned Quick Look support as an added bonus — but there is a better option. (See MPlayer OSX Extended above.)
VLC media player (Bad/Evil)
VLC is weird or evil in many ways. We recommend avoiding it and its strange conventions/capabilities.