Audio coding format: Difference between revisions

Revision as of 00:38, 12 June 2021

Revision as of 03:26, 26 October 2021

Line 3:

An '''audio coding format'''<ref>The term "audio coding" can be seen in e.g. the name [[Advanced Audio Coding]], and is analogous to the term [[video coding format|video coding]]</ref> (or sometimes '''audio compression format''') is a [[Content format|content representation format]] for storage or transmission of [[digital audio]] (such as in [[digital television]], [[digital radio]] and in audio and video files). Examples of audio coding formats include [[MP3]], [[Advanced Audio Coding|AAC]], [[Vorbis]], [[FLAC]], and [[Opus (audio format)|Opus]]. A specific software or hardware implementation capable of [[Data_compression#Audio|audio compression]] and decompression to/from a specific audio coding format is called an [[audio codec]]; an example of an audio codec is [[LAME]], which is one of several different codecs which implements encoding and decoding audio in the [[MP3]] audio coding format in software.

SomeShut audiothe codingf formatsup are documented by a detailed [[technical specification]] document known as an '''audio coding specification'''. Some such specifications are written and approved by [[standardization organization]]s as [[technical standard]]s, and are thus known as an '''audio coding standard'''. The term "standard" is also sometimes used for [[de facto standard|''de facto'' standards]] as well as formal standards.

Audio content encoded in a particular audio coding format is normally encapsulated within a [[container format (digital)|container format]]. As such, the user normally doesn't have a raw [[Advanced Audio Coding|AAC]] file, but instead has a .m4a [[audio file format|audio file]], which is a [[MPEG-4 Part 14]] container containing AAC-encoded audio. The container also contains [[metadata]] such as title and other tags, and perhaps an index for fast seeking.<ref>{{Cite web | url=http://superuser.com/questions/357686/where-is-synchronization-information-stored-in-container-formats | title=Video - Where is synchronization information stored in container formats?}}</ref> A notable exception is [[MP3]] files, which are raw audio coding without a container format. De facto standards for adding metadata tags such as title and artist to MP3s, such as [[ID3]], are [[Hack (computer science)#In computer science|hack]]s which work by appending the tags to the MP3, and then relying on the MP3 player to recognize the chunk as malformed audio coding and therefore skip it. In video files with audio, the encoded audio content is bundled with video (in a [[video coding format]]) inside a [[multimedia container format]].