Document Revision History

This table describes the changes to Core Audio Data Types Reference.


Added a description for the kAudioFormatMPEG4AAC_ELD_SBR audio data format identifier.


Added a description for the “kAudio_FileNotFoundError” result code.

2010-04-10Updated for iOS 4.0.

Improved the formatting of channel layout information in “Audio Channel Layout Tags.”


Added descriptions for 28 new channel layout constants in “Audio Channel Layout Tags”; these constants describe Blu-ray Disc channel layouts for Enhanced AC-3 (Dolby Digital Plus) and DTS (Digital Theater Sound) formats.


Added a description for the kAudioFormatMPEG4AAC_ELD audio format constant.


Improved the description of the AudioStreamBasicDescription structure.


Added descriptions for three result codes: “kAudio_UnimplementedError”, “kAudio_ParamError”, and “kAudio_MemFullError”.


Added a description for the kAudioUnitSampleFractionBits constant.


Added descriptions for the kAudioChannelLayoutTag_AC3_3_0 and kAudioChannelLayoutTag_AudioUnit_7_1_Front surround-sound constants.


Added descriptions for the kSMPTETimeType2398, kSMPTETimeType50, kSMPTETimeType5994Drop, and kSMPTETimeType60Drop timecode constants.


Updated for iPhone OS 3.0.


Added descriptions for the new kAudioFormatDVIIntelIMA, kAudioFormatMicrosoftGSM, and kAudioFormatAES3 audio data format constants. Updated declaration for the FillOutASBDForLPCM C++ inline function.


Clarified the distinction between the availability of audio data format identifier symbols and the presence of audio codecs in the operating system. See the Discussion for “Audio Data Format Identifiers.”

2008-09-09Updated for iOS version 2.1.
2008-07-08Updated for iOS 2.0.
2007-01-08New document that lists and describes the data types and constants used throughout the Core Audio API.