Editing Advanced Audio Coding (section)

==Container formats{{Anchor|LATM|LOAS}}==
{{Main|MPEG-4 Part 3#Audio storage and transport|l1=MPEG-4 Part 3: Audio storage and transport}}
{{See also|Comparison of video container formats#Audio coding formats support}}
In addition to the [[MP4]], [[3GP]] and other container formats based on [[ISO base media file format]] for file storage, AAC audio data was first packaged in a file for the MPEG-2 standard using Audio Data Interchange Format (ADIF),<ref name="aes2003">{{Cite conference|last1=Wolters |first1=Martin |first2=Kristofer |last2=Kjorling |first3=Daniel |last3=Homm |first4=Heiko |last4=Purnhagen |title=A closer look into MPEG-4 High Efficiency AAC |page=3 |url=http://www.telos-systems.com/techtalk/hosted/HE-AAC.pdf |access-date=2008-07-31 |url-status=dead |archive-url=https://web.archive.org/web/20031219000444/http://telos-systems.com/techtalk/hosted/HE-AAC.pdf |archive-date=2003-12-19 }} Presented at the 115th Convention of the Audio Engineering Society, 10–13 October 2003.</ref> consisting of a single header followed by the raw AAC audio data blocks.<ref name="diipp">{{cite web|url=http://www.digitalpreservation.gov/formats/fdd/fdd000112.shtml|title=Advanced Audio Coding (MPEG-2), Audio Data Interchange Format |publisher=Library of Congress / National Digital Information Infrastructure and Preservation Program |date=7 March 2007 |access-date=2008-07-31 | archive-url= https://web.archive.org/web/20080730205354/http://www.digitalpreservation.gov/formats/fdd/fdd000112.shtml | archive-date= 30 July 2008  | url-status= live}}</ref> However, if the data is to be streamed within an MPEG-2 transport stream, a self-synchronizing format called an '''Audio Data Transport Stream''' ('''ADTS''') is used, consisting of a series of frames, each frame having a header followed by the AAC audio data.<ref name="aes2003"/> This file and streaming-based format are defined in [[MPEG-2 Part 7]], but are only considered informative by MPEG-4, so an MPEG-4 decoder does not need to support either format.<ref name="aes2003"/> These containers, as well as a raw AAC stream, may bear the .aac file extension. [[MPEG-4 Part 3]] also defines its own self-synchronizing format called a Low Overhead Audio Stream (LOAS) that encapsulates not only AAC, but any MPEG-4 audio compression scheme such as [[TwinVQ]] and [[Audio Lossless Coding|ALS]]. This format is what was defined for use in DVB transport streams when encoders use either [[Spectral band replication|SBR]] or [[parametric stereo]] AAC extensions. However, it is restricted to only a single non-multiplexed AAC stream. This format is also referred to as a Low Overhead Audio Transport Multiplex (LATM), which is just an interleaved multiple stream version of a LOAS.<ref name="aes2003"/>