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, Advanced Video Coding (part 10), High 4:2:2 ProfileNOTE: this Web page drafted prior to the amendment of the standard to add the four High profiles. Comments welcome. |
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| Description | The High 4:2:2 Profile MPEG-4_AVC (from ITU-T H.264) supports 4:2:2 chroma at 10 bits per channel, adaptive macroblock-level switching between 8x8 and 4x4 transform block size, encoder-specified quantization scaling matrices, encoder-specified separate control of the quantization parameter for each chroma component, and monochrome sequences. The Overview and Introduction to the Fidelity Range Extensions states that "High 4:2:2 is expected to be used frequently in studio environments." |
| 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_H422P, MPEG-4 File Format, V.2, with AVC, High 4:2:2 Profile |
| LC experience or existing holdings | |
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| LC preference |
| Disclosure | Open standard. See MPEG-4_AVC. |
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| Documentation | See MPEG-4_AVC. This profile is not yet in the formal specification; information may be found in Overview and Introduction to the Fidelity Range Extensions. |
| Adoption | See MPEG-4_AVC_HP and MPEG-4_AVC. |
| 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 MPEG-4_AVC. Depends in part on the level and encoding algorithm selected. The High 4:2:2 Profile has the potential to produce greater clarity than MPEG-4_AVC_BP, MPEG-4_AVC_MP, MPEG-4_AVC_EP, MPEG-4_AVC_HP, and MPEG-4_AVC_H10P at a given picture size and data rate. By the same token, MPEG-4_AVC_H422P clarity can be surpassed by MPEG-4_AVC_H444P. |
| Functionality beyond normal rendering | See MP4_FF_2. |
| Tag | Value | Note |
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| Filename extension | See note. | Pertains to the file format; see MP4_FF_2 |
| Internet Media Type | See note. | Pertains to the file format; see MP4_FF_2 |
| Magic numbers | See note. | Pertains to the file 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_AVC bitstreams in MP4_FF_1 (unlikely) would occasion the use of mp41; in MP4_FF_2 (more likely), use mp42. |
| Other | Profile indicator. Not yet assigned; profile_idc is described as a part of Annex A of Part 10 of the standard, pp. 204-05. |
| General | |
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| History |
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