iPhoneExtAudioFileConvertTest demonstrates the use of the ExtAudioFile API to convert from one audio format and file type to another and will support AAC encode on appropriate hardware such as the iPhone 3GS.
All the relevant code is in the file ExtAudioFileConvert.cpp.
Touching the "Convert" button calls the function DoConvertFile() producing an output.caf file using the encoding and sample rate chosen in the UI.
The output.caf file is then played back after conversion using AVAudioPlayer to confirm success and Audio format information for both the sournce and output file is displayed.
Interruption handling during audio processing (conversion) is also demonstrated.
Extended Audio File Services provides simplified audio file access, combining features of Audio File Services and Audio Converter Services. It provides a unified interface for reading and writing compressed as well as linear PCM audio files.