USF - Universal Subtitle Format

This page is temporary since we lost the original site design on server change. Either the original is found and reinstalled or a new decent page will be set up.

Universal Subtitle Format is a XML based styled text video subtitle format designed for flexibility and as official subtitle format for inclusion in the Matroska multimedia container.

The format is based on XML for many reasons: flexibility, human readability, portability, unicode support, hierarchical system and easier management.

• USF project page
• Specification: Draft 0.16, 2002 (zip)
• Proposals: Extension proposals, 2003-2005 (dir, .DTD)
• HTML Reference: Attempt at a more detailed reference, includes many proposal elements/attributes and it's "profile/level" classification should be ignored. 2005

Features and Advantages

• XML based for flexibility and interoperability
• Easy to learn synthax, similar to HTML
• Time based to avoid problems with video frame rate conversion
• 4 element types:
  • text
  • image
  • karaoke
  • shape
• Powerful element positioning system:
  • 9 alignment types (TopLeft, ...,MiddleCenter, ...,BottomRight)
  • Relative to window or video
  • Horizontal and vertical margin in pixel or percent of window/video
• Definable styles: separation of presentation and content similar to CSS classes, but declared in XML
• Text classes and individual attributes assignable and overwritable on a per-letter basis
• Simple text attributes:
  • color
  • italic, weight, underline
  • size
  • font
  ..as well as more advanced attributes
• Meta information to increase archiving and search facilities:
  • title
  • author(s)
  • language (ISO639-2 code plus a custom text string)
  • date
  • comment

2006-12-03 - XHTML 1.0 Strict - CSS 1 and 2.1