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Identification and description

Full name	Information technology -- Coding of audio-visual objects (formal name) MPEG-4, Advanced Video Coding (part 10), Extended Profile
Description	Extended is the most complex of the three original MPEG-4_AVC profiles (Baseline, Main, and Extended); it places the greatest demands on a decoder. The constraints on this profile are limited and, like the Main Profile, examples may include intra (I), predicted (P), and bidirectional (B) slice types (slice is the MPEG-4_AVC term for a single macroblock or a set of macroblocks that make up a portion of an individual picture.) For a discussion of the contraints and the levels that may be used in this profile, see Appendix A in Part 10 of the standard, pp. 204-211. The extensions described here predate the FRExt (Fidelity Range Extensions), being finalized in 2005 and represented by four new profiles: MPEG-4_AVC_HP, MPEG-4_AVC_H10P, MPEG-4_AVC_H422P, and MPEG-4_AVC_H444P.
Production phase	Generally a final-state (end-user delivery) format.
Relationship to other formats
Subtype of	MPEG-4_AVC
Used by	MP4_FF_2_AVC_EP, MPEG-4 File Format, V.2, with AVC, Extended Profile

Local use

LC experience or existing holdings
LC preference

Sustainability factors

Disclosure	Open standard. See MPEG-4_AVC.
Documentation	See MPEG-4_AVC.
Adoption	See MPEG-4_AVC.
Licensing and patent claims	See MP4_FF_2.
Transparency	See MP4_FF_2.
Self-documentation	See MP4_FF_2.
External dependencies	See MP4_FF_2.
Technical protection considerations	See MP4_FF_2.

Quality and functionality factors (video)

Normal rendering	Good support.
Clarity (support for high image resolution)	See MPEG-4_AVC. Depends in part on the level and encoding algorithm selected. The Extended Profile will produce greater clarity than the MPEG-4_AVC_BP (Baseline Profile) and the MPEG-4_AVC_MP (Main Profile) at a given picture size and data rate. The clarity in all three of the original profiles is surpassed by the four FRExt (Fidelity Range Extension) profiles: MPEG-4_AVC_HP, MPEG-4_AVC_H10P, MPEG-4_AVC_H422P, and MPEG-4_AVC_H444P.
Fidelity (support for high audio resolution)	See MP4_FF_2.
Support for multiple sound channels	See MP4_FF_2.
Functionality beyond normal video rendering	See MP4_FF_2.

File type signifiers

Tag type	Value	Note
Filename Extension	mp4
Internet Media Type	See MP4_FF_2
Magic numbers	See MP4_FF_2
Profile indicators	88	For profile_idc; Annex A of Part 10 of the standard, pp. 204-05.
File type brand	See note	Indicated in file wrapper and relates to "brands" defined in ISO_BMFF. Wrapping MPEG-4_AVC bitstreams in MP4_FF_1 would occasion the use of mp41; in MP4_FF_2, use mp42.

Notes

General
History

Format specifications

URLs

Print
From the ISO web site (http://www.iso.ch/ISO/en/):
• ISO/IEC 14496-10:2003 Information technology -- Coding of audio-visual objects -- Part 10: Advanced Video Coding
• ISO/IEC 14496-15:2003 Information technology -- Coding of audio-visual objects -- Part 15: Advanced Video Coding (AVC) file format

Useful references

URLs
• See MP4_FF_2.

Print
• See MP4_FF_2.