With the file extension CAF so-called audio core files (files) are marked. Audio Core is a digital audio container format based on Apple's proprietary technology. In addition to the audio data, CAF files can also store text annotations, markers and channel arrangements. The Audio Core was developed with the aim of not being subject to the limitations of the aiff and wav format. A CAF file can be larger than 4GB and contain any number of channels.
Since the Core Audio format acts as a container format, it can include various audio formats. As of Mac OSX 10.4, the CAF format is supported natively, with the previous version Quicktime 7 or higher must be installed.
The CAF format is used by some sound programs on the Mac for loops and sound effects, for example. In addition, it is stored by some recording programs (eg QuickVoice) for Mac, iPhone and iPad.
Most often resolving problems with opening CAF files is very simple. Just install an appropriate program that supports such files. All of the listed programs support CAF files, but may vary in offered function and purpose. Some programs may be capable only of viewing contents of CAF files or offer file conversion options, but may not be capable of editing such files.
It is possible that although a compatible program has been installed on user’s system, it is not used by the system to open it. This may happen because no default application was associated with this type of files. To associate CAF files with given application, select "Open with" from drop-down menu (accessed by right-clicking on the file). Then select from the list the program or application you want to be used to open this type of file. If the QuickTime Player applications is not on the list, select "Browse" option in order to manually locate the directory where QuickTime Player has been installed.
Sometimes problems with opening CAF files may not lie with the application itself, but can arise due to other causes, such as: