MPEG-4, Visual Coding, Main Profile

Sustainability of Digital Formats: Planning for Library of Congress Collections

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MPEG-4, Visual Coding, Main Profile

Table of Contents

Identification and description
Local use
Sustainability factors
Quality and functionality factors
File type signifiers
Notes
Format specifications
Useful references

Format Description Properties

ID: fdd000048
Short name: MPEG-4_V_MP
Content categories: moving-image
Format Category: encoding
Other facets: unitary, binary, sampled
Last significant FDD update: 2011-12-01
Draft status: Full

Identification and description

Relationship to other formats
Full name	ISO/IEC 14496-2:2004. Information technology -- Coding of audio-visual objects -- Part 2: Visual. Main Profile (formal name); MPEG-4, Visual Coding, Main Profile (common name)
Description	See also MP4_FF_2 and MPEG-4_V. The Main Profile was created to serve broadcast services, permitting the highest quality, and supporting arbitrarily shaped objects using grayscale coding. The Main Profile permits the use of the following visual object types: Simple: rectangular video, uses intra (I) and predicted (P) video object planes (VOPs, the MPEG-4 term for frames). Core: arbitrarily shaped video, uses a tool superset of Simple, adds bidirectional (B) video object planes (VOPs), binary shape coding, and supports temporal scalability based on sending extra P-VOPs. Main: arbitrarily shaped video, adds to Core the coding of grayscale shapes, sprites (object in memory with all pixel information, e.g., the background of scene), and interlaced coding. Scalable Texture: arbitrarily shaped still image with wavelet compression and incremental download. Three compression levels are permitted; the highest accepts up to 32 objects (Simple, Core, or Main) for a maximum total bit rate of 38 Mbps.
Production phase	Generally a final-state (end-user delivery) format.
Subtype of	MPEG-4_V, MPEG-4, Visual Coding (Part 2)
Used by	MP4_FF_2_V, MPEG-4 File Format, V.2, with Visual Coding (All Profiles)

Local use

LC experience or existing holdings
LC preference

Sustainability factors

Disclosure	Open standard. See MP4_FF_2.
Documentation	See MP4_FF_2.
Adoption	Actual adoption not known to the compilers of this document.
Licensing and patents	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

Moving Image
Normal rendering	Good support.
Clarity (high image resolution)	See MPEG-4 and MPEG-4_V. Potential for greater clarity at a given picture size, data rate, and encoding algorithm, than some other MPEG-4 profiles, e.g., Simple, Simple Scalable, Advanced Simple, and Core Profiles.
Functionality beyond normal rendering	See MPEG-4.

File type signifiers and format identifiers

Tag	Value	Note
Filename extension	mp4
Internet Media Type	See related format.	See MP4_FF_2
Magic numbers	See related format.	See MP4_FF_2
File type brand (ISO Base Media File Format)	See note.	Indicated in file wrapper and relates to "brands" defined in ISO_BMFF. Wrapping MPEG-4_V bitstreams in MP4_FF_1 would occasion the use of mp41; in MP4_FF_2, use mp42. See Part 15 of the standard, pp. 2-9, 13.
Indicator for profile, level, version, etc.	See note.	Indicators for Main Profile, levels 2, 3, and 4 are 00110010, 00110011, 00110100, respectively. From Annex G of ISO/IEC 14496-2:2004, Table G.1
Pronom PUID	See note.	PRONOM has no corresponding entry as of July 2022.
Wikidata Title ID	See related format.	See MPEG-4, Visual Coding (Part 2) (H.263).

Notes

General
History

Format specifications

See Disclosure under Sustainability factors.

Useful references

URLs

See MP4_FF_2.

Books, articles, etc.

Pereira, Fernando, and Touradj Ebrahimi, The MPEG-4 Book, Upper Saddle River, NJ: IMSC Press, 2002, p. 599.

Last Updated: 07/22/2022