<<A number of audio codecs are included as part of the MMF which provide a number of standard codec conversions between common audio data types such as uLaw, aLaw, pcm8, pcm16 and gsm610. These can be found in the multimedia component directory under \Mmf\Src\Plugin\Codec\Audio.
Since most of these codecs are relatively simple, they provide a good source of example code for writing a codec plugin. There are also a number of test codecs in the UnitTest directory in the \acod and \basecl sub-directories which could be used as a template for writing a new CMMFCodec plugin.>>
Where are these folders inside the SDK?
These two paragraphs come from "How to Write a Codec Plugin" inside the 2nd ed. FP2 SDK. They are also here: