Hypervideo Markup Language

(Formerly known as “OVML” for Open Video Markup Language)

HVML is an RDFa-compatible, XML-based markup language for codifying information pertaining to audio-visual media such as films, television, home movies, or any other moving image, digital or analog.

Its primary goal is to provide a standardized syntax and interface for storing and querying video metadata. The type of data it encodes is comparable to those found on IMDb, TMDb, Wikipedia, and Amazon, however it is not meant to replace these services; in theory they could all implement HVML.

It is a similar technology to MPEG-7, but more limited in scope (to make it easier for humans to understand and author), with the goal of being free of patent encumbrance.

Inspired by the article “How The Television Will Be Revolutionized: The Exciting Future of the iPad, Internet TV, and Web 3.0”, which talks about an “OVML”, its uses cases do not coincide 100% with the ones the author mentions.

Use Cases

  • Video players displaying metadata to an end user, as with MP3 ID3 tags.
  • Search engines displaying metadata to an end user, as with schema.org (but with a more specialized vocabulary).
  • Historians wishing to catalog the world’s films.
  • Archivists wishing to catalog internal libraries (such as the HFA).
  • Video content authors wishing to store information about their films.
  • Content publishers wishing to store/query/display information about video media being delivered and/or discussed.
  • Educators and students wishing to teach or understand the minute details of films and video.
  • Programmers wishing to ingest, convert, display, or splice video files who must reference technical details like frame rate or pixel aspect ratio without relying on the often erroneous or incomplete information reported by the container.

Cheat Sheet

  • Content-Type:

    • Working: application/prs.hvml+xml
    • Proposed: application/hvml+xml (pending IETF standardization)
    • Deprecated: application/ovml+xml
  • Extensions:

    • Standard: .hvml
    • Alternative: .xml
    • Deprecated: .ovml
  • Namespace:

    • Standard: https://hypervideo.tech/hvml#
    • Deprecated: http://vocab.nospoon.tv/ovml#
  • Namespace prefix:

    • Standard: hvml
    • Deprecated: ovml


  1. Single-page version
  2. Rationale
  3. The Elements of HVML
    1. The hvml Element
    2. The title Element
    3. The video Element
    4. The series Element
    5. The group Element
    6. The rating Element
    7. The verdict Element
  4. Glossary of Terms