MPEG-4

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Revision as of 14:57, 30 November 2012 (view source) Gmcgath (Talk | contribs) (Changed category to video) ← Older edit		Latest revision as of 05:08, 26 May 2021 (view source) Dan Tobias (Talk | contribs)
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	|formattype=electronic		|formattype=electronic
	|subcat=Video		|subcat=Video
−	|extensions={{ext|mp4}}	+	|subcat2=MPEG
−	|mimetypes={{mimetype|audio/mp4,video/mp4}}	+	|thiscat=MPEG-4
		+	|extensions={{ext|mp4}}, {{ext|m4a}}, {{ext|m4b}}, {{ext|m4p}}, {{ext|m4r}}, {{ext|aac}}
	}}		}}
		+	[[MPEG-4]] is an expansive collection of standards related to a set of multimedia formats. It is developed by the Moving Picture Experts Group, codified as ISO/IEC 14496. Saying just what the "MPEG-4 file format" is, is a somewhat complicated question. Parts 12, 14, and 15 specifically refer to "file formats".
−	'''MP4''' is the popular name for the MPEG-4 standard, defined by the Moving Picture Experts Group, codified as ISO/IEC 14496. Saying just what the "MP4 file format" is, is a somewhat complicated question. Parts 12, 14, and 15 specifically refer to "file formats.".	+	Part 3 defines compressed audio formats, including [[AAC]], [[MPEG-4 ALS|ALS]], and [[MPEG-4 SLS|SLS]].
−	Part 12 is known as ISO Base Media File Format. It is derived largely from Apple's QuickTime format and is described as a "general format for timed sequences of media data."	+	Part 10: Refer to [[H.264]].
−	Part 14 is an extension of Part 12. The recommended extension for it is ".mp4", though ".m4a" is often used for audio-only files.	+	Part 12: Refer to [[ISO Base Media File Format]].
−	Part 15 is "MPEG-4 File Format for Advanced Video Coding." This specifies the use of Part 10 encoding with the Part 12 file format. the extension ".avc" is often used with it.	+	Part 14: Refer to [[MP4]].
−	"MP4 audio players" don't always support the MPEG-4 file formats, sometimes supporting only the AAC audio encoding from MPEG-4, Part 3 (aka MPEG-4 Audio). These would more properly be called AAC files, with the extension ".aac".	+	Part 15: Refer to [[AVC (file format)]].
		+
		+	Part 22: Refer to [[Open Font Format]].
		+
		+	"MP4 audio players" don't always support the MPEG-4 file formats, sometimes supporting only the AAC audio encoding from MPEG-4, Part 3 (aka MPEG-4 Audio). These would more properly be called [[AAC]] files, with the extension ".aac".
		+
		+	MPEG-4 is encumbered by numerous patents, and (at least) commercial implementers have to secure licenses. Many of the licensing aspects are handled by a group called MPEG LA.
		+
		+	== Links ==
		+	* [[Wikipedia:MPEG-4|Wikipedia: MPEG-4]]
		+	* [http://www.mp4ra.org/ MP4 Registration Authority]
		+	* RFC 4337: MPEG-4 MIME type registration
		+
		+	[[Category:Audio and Music]]

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Latest revision as of 05:08, 26 May 2021

File Format
Name	MPEG-4
Ontology	Electronic File Formats Video MPEG MPEG-4
Extension(s)	.mp4, .m4a, .m4b, .m4p, .m4r, .aac

MPEG-4 is an expansive collection of standards related to a set of multimedia formats. It is developed by the Moving Picture Experts Group, codified as ISO/IEC 14496. Saying just what the "MPEG-4 file format" is, is a somewhat complicated question. Parts 12, 14, and 15 specifically refer to "file formats".

Part 3 defines compressed audio formats, including AAC, ALS, and SLS.

Part 10: Refer to H.264.

Part 12: Refer to ISO Base Media File Format.

Part 14: Refer to MP4.

Part 15: Refer to AVC (file format).

Part 22: Refer to Open Font Format.

"MP4 audio players" don't always support the MPEG-4 file formats, sometimes supporting only the AAC audio encoding from MPEG-4, Part 3 (aka MPEG-4 Audio). These would more properly be called AAC files, with the extension ".aac".

MPEG-4 is encumbered by numerous patents, and (at least) commercial implementers have to secure licenses. Many of the licensing aspects are handled by a group called MPEG LA.

[edit] Links

• Wikipedia: MPEG-4
• MP4 Registration Authority
• RFC 4337: MPEG-4 MIME type registration