MPEG-4

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	|formattype=electronic		|formattype=electronic
	|subcat=Video		|subcat=Video
		+	|subcat2=MPEG
	|thiscat=MPEG-4		|thiscat=MPEG-4
−	|extensions={{ext|mp4}}, {{ext|aac}}, others	+	|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".		[[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 [[MPEG-4 ALS|ALS]] and [[MPEG-4 SLS|SLS]].	+	Part 3 defines compressed audio formats, including [[AAC]], [[MPEG-4 ALS|ALS]], and [[MPEG-4 SLS|SLS]].
	Part 10: Refer to [[H.264]].		Part 10: Refer to [[H.264]].
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	Part 22: Refer to [[Open Font 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".	+	"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.		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.
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	* [http://www.mp4ra.org/ MP4 Registration Authority]		* [http://www.mp4ra.org/ MP4 Registration Authority]
	* RFC 4337: MPEG-4 MIME type registration		* RFC 4337: MPEG-4 MIME type registration
−	* [http://inkdroid.org/journal/2014/05/23/realaudio-aac-and-archivy/ RealAudio, AAC and Archivy]
	[[Category:Audio and Music]]		[[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