Sustainability of Digital Formats
Planning for Library of Congress Collections
Sustainability of Digital Formats
|
|
|
|
| Introduction | Sustainability Factors | Content Categories | Format Descriptions | Contact | |
| Full name | Information technology -- Generic coding of moving pictures and associated audio information (formal name) MPEG-2, Main Profile |
| Description | Permits the use of Intra-coded (I) frames, predicted (P) frames, and bidirectionally predicted (B) frames. Conformance points for this bitstream exist at the following levels: Low, Main, High-1440, and High. At the Main Level, the broadcast-stream picture size is 720x576 pixels (non-square pixels), with color sampling of 4:2:0 and a maximum data rate of 15 Mb/s. |
| Production phase | Generally a final-state (end-user delivery) format; may be used as a middle-state (broadcast production) format. |
| Relationship to other formats | |
| Subtype of | MPEG-2 |
| LC experience or existing holdings | See MPEG-2 |
| LC preference | For file-based compressed video, conform to or approximate MPEG-2_422 (4:2:2 Profile) at Main Level (aka MPEG-2 422@ML) or MPEG-2_MP (this document; Main Profile) at Main Level (aka MPEG-2 MP@ML). Uncompressed or losslessly compressed copies are preferred to compressed (for future development). |
| Disclosure | Open standard. See MPEG-2 |
| Documentation | See MPEG-2 |
| Adoption | MPEG-2_MP (Main Profile) is used by broadcasters and cablecasters, who may also use MPEG-2_422 (4:2:2 Profile). Vanderbilt University is using MPEG-2_MP (Main Profile) as the "target" for its digitization of news broadcasts. |
| Licensing and patent claims | See MPEG-2. |
| Transparency | See MPEG-2. |
| Self-documentation | See MPEG-2. |
| External dependencies | See MPEG-2. |
| Technical protection considerations | See MPEG-2. |
| Normal rendering | Good support. |
| Clarity (support for high image resolution) | See MPEG-2. At a given picture size, data rate, and encoding algorithm, MPEG-2_MP (Main Profile) will produce greater clarity than MPEG-2_SP (Simple Profile) but less than MPEG-2_422 (4:2:2 Profile). |
| Fidelity (support for high audio resolution) | See MPEG-2. |
| Support for multiple sound channels | See MPEG-2. |
| Functionality beyond normal video rendering | See MPEG-2. |
| Tag type | Value | Note |
| Filename Extension | mpg, mpeg | There is no explicit MPEG-2 file format; MPEG-2 content "ready to be delivered" is exchanged in files with these extensions. |
| Internet Media Type | See MPEG-2 | |
| Magic numbers | See MPEG-2 |
| General | |
| History |
URLs
Print
See MPEG-2.
URLs
• See MPEG-2.
|
|