LCVideoMD is an XML schema developed by the Library of Congress for recording the technical characteristics of video digital objects. It provides the structured technical detail needed for long-term digital preservation of video content, capturing codec, resolution, frame rate, and color information. Like its companion AudioMD, VideoMD is typically used as an extension schema within METS documents.
Background
VideoMD was developed by the Library of Congress alongside AudioMD in the mid-2000s as part of the effort to create media-specific technical metadata schemas for digital preservation. While METS provided a general packaging standard for digital objects, it needed extension schemas to capture the domain-specific technical details of different media types. VideoMD addresses the video domain, drawing on expertise in video engineering and digital preservation practice. The two schemas share a homepage at the Library of Congress and are commonly deployed together for audiovisual materials.
Purpose & Scope
VideoMD captures the technical properties needed to understand, render, and preserve video digital objects. It is intended for use by digital preservation systems, digital asset management platforms, and institutional repositories that hold video content. The schema addresses both file-level encoding characteristics and the visual properties of the video signal.
Key Elements / Properties
| Element | Description |
|---|---|
compression |
Codec and compression scheme used |
dataRate |
Bit rate of the video stream |
dataRateMode |
Fixed or variable bit rate |
frame |
Frame dimensions and aspect ratio |
frameRate |
Frames per second |
resolution |
Spatial resolution of the video |
aspectRatio |
Display aspect ratio |
colorSpace |
Color model (e.g., YUV, RGB) |
bitDepth |
Bits per color channel |
duration |
Length of the video content |
scanType |
Interlaced or progressive scan |
Serializations & Technical Formats
VideoMD is defined as an XML Schema (XSD). Instances are XML documents, typically embedded within METS <techMD> or <digiprovMD> sections. The schema is available for download from the Library of Congress website.
Governance & Maintenance
VideoMD is maintained by the Library of Congress Network Development and MARC Standards Office. Updates are published on the LC standards website. As a relatively stable technical metadata schema, it undergoes infrequent revisions.
Notable Implementations
VideoMD is used within the Library of Congress's own digital preservation infrastructure. It is supported by digital preservation tools and frameworks that work with METS, including Archivematica and DSpace configurations for audiovisual materials. Institutions with significant video collections -- including national libraries, public broadcasters, and film archives -- use VideoMD for preservation metadata.
Related Standards
- AudioMD -- The companion schema for audio technical metadata, sharing the same homepage and design philosophy.
- METS -- The Metadata Encoding and Transmission Standard, which serves as the primary container for VideoMD metadata.
- PREMIS -- The preservation metadata standard, which addresses broader preservation concerns alongside VideoMD's technical focus.
- MXF -- Material Exchange Format, a container format for professional video that includes its own metadata capabilities.