A fork/clone of the subversion repository at http://svn.cod3r.com/a52codec for the a52codec included as part of the Perian releases. Although Perian has been retired, the source code and downloads continue to be available.
The trunk branch represents the latest code from the subversion repository. The master branch represents the version that was released with Perian 1.2.3 plus some Xcode project updates and a fix for an incorrect header (description here) generated while performing AC-3 pass through. The various perian-* tags indicate which version of the a52codec source was included with each Perian release.
You can also clone the project with Git by running:
$ git clone git://github.com/mackyle/a52codec
Pre-built universal binaries of the A52Codec.component software runnable on Mac OS X 10.4 or later which include the AC-3 pass through fix are available from the a52codec project’s downloads area.
Visit the GitHub project page (source code etc.) at http://github.com/mackyle/a52codec.