Sustainability of Digital Formats
Planning for Library of Congress Collections
Sustainability of Digital Formats
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| Introduction | Sustainability Factors | Content Categories | Format Descriptions | Contact | |
| Full name | Information technology -- Coding of audio-visual objects (formal name)MPEG-4, Visual Coding, Advanced Simple Profile |
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| Description | See also MP4_FF_2 and MPEG-4_V. Useful in Internet streaming applications and other low bandwidth applications but can scale to television broadcast quality.1 The Advanced Simple 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). • Advanced Simple: rectangular video, enhanced compression, adds bidirectional (B) video object planes (VOPs). Six compression levels are permitted (0 to 5); Levels 0 to 3 have bit rates from 128 to 768 kbps; support for interlaced coding is added for Levels 4 and 5 with bit rates from 3 to 8 Mbps. |
| Production phase | Generally a final-state (end-user delivery) format. |
| Relationship to other formats | |
| 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) |
| LC experience or existing holdings | |
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| LC preference |
| Disclosure | Open standard. See MP4_FF_2. |
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| 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. |
| Moving Image | |
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| Normal rendering | Good support. |
| Clarity (high image resolution) | See MP4_FF_2 and MPEG-4_V. Other profiles will produce greater clarity than the Simple Scalable Profile at a given picture size, data rate, and encoding algorithm. |
| Functionality beyond normal rendering | See MP4_FF_2. |
| Tag | Value | Note |
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| Filename extension | mp4 |
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| Internet Media Type | See MP4_FF_2 |
**See MP4_FF_2 |
| Magic numbers | See MP4_FF_2 |
**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. |
| Other | 11110000, 11110001, 11110010, 11110011, 11110100, 11110101 |
Profile and level indicators. For profile_and_level_indication for Advanced Simple Profile, levels 0, 1, 2, 3, 4, and 5; from Annex G of ISO/IEC 14496-2:2004, as amended Amd.2:2002, pp. 52-53. |
| General | Fernando Pereira and Touradj Ebrahimi report that the Advanced Simple Profile "represents a compromise between the desire to support interlace at higher bit rates and the desire to keep the number of profiles manageable. . . . It is likely that another level, termed 3b, will be added . . . [which] will allow higher bit rates without having to support interlaced coding." 2 |
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| History |
1 Pereira, Fernando, and Touradj Ebrahimi, The MPEG-4 Book, Upper Saddle River, NJ: IMSC Press, 2002, p. 598.
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