by Fernando Pereira
Keywords: audio profile, audio level, conformance
This appendix includes the profiles and levels specified in MPEG-4 Audio both in Version 1 and in Version 2 [MPEG4-3]. The MPEG-4 Audio standard defines (as of October 2001) 23 object types and 8 profiles as explained in Chapter 13.
Four audio profiles have been defined in MPEG-4 Audio Version 1: Main, Scalable, Speech, and Synthetic. Four additional profiles were specified in MPEG-4 Audio Version 2: High-Quality Audio, Low-delay Audio, Natural Audio, and Mobile Audio Internetworking (MAUI).