It is difficult for a browser to extract semantic information about a video recording described on a web page. Metadata such as speaker, actor, publisher, production company, title of the work, release date, download link, related image artwork and tags provide relevant context for the video recording, but are currently (2008) inaccessible to computers.
Having such information marked up in a semantic way can provide a number of benefits to the viewer. If a web browser understands that a particular web page contains a TV episode containing a particular actor, it can produce richer interactions. For example, specific searches may be performed for directors and movies via general search services such as Google and Wikipedia. Specific search services may also be queried such as IMDB, The Internet Archive, The BBC, or Bitmunk. Additionally, classification by crawlers can become more accurate. If there are 5 movies that are found on a page made by the same director, and that content consumes a significant portion of the page, it can be assumed that the page is not only about movies, but also about a particular director.
In order to enable and encourage the sharing, distribution, syndication, and aggregation of video content, the authors propose the Video RDF vocabulary, an open standard for distributed video metadata. The authors have researched both numerous examples in the wild and earlier attempts at video metadata formats, and have designed the Video RDF Vocabulary around a simple minimal schema for video content. Feedback is encouraged and open participation is desired from all that are interested in contributing to the open exchange of video metadata on the Internet.
The easiest way to use the Video RDF Vocabulary is to embed semantic video metadata in your web pages using RDFa. For examples on how to do this, please visit the Video RDF Vocabulary section on the RDFa wiki.
The Video RDF Vocabulary relies heavily on aggregating functionality in previously defined vocabularies. Vocabulary term re-use is of primary importance. What follows are the vocabularies on which the RDF Video Vocabulary depends:
| Status | stable |
| Description | A recording of a series of images that, when played in order, recreate a visual account of events. |
| Subclass of | media:Recording |
| Status | unstable |
| Description | A video recording that is a part of a larger series of video recordings that are meant to be watched in a serial manner. |
| Subclass of | video:Recording |
| Status | unstable |
| Description | A long format video recording that tells a self-contained story arc. . |
| Subclass of |
| Status | unstable |
| Description | A collection of one or more video episodes that are meant to be played in a serial order from beginning to end. |
| Subclass of |
| Status | stable |
| Description | title of the video recording |
| Datatype | plain literal |
| Status | stable |
| Description | The primary creator or performer of the video recording. |
| Datatype (pick one) |
|
| Status | stable |
| Description | An entity that helped create the video recording. |
| Datatype (pick one) |
|
| Status | stable |
| Description | The date the video recording was published. |
| Datatype (pick one) | xsd:date using ISO-8601 |
| Status | stable |
| Description | The description associated with the video recording. |
| Datatype (pick one) |
|
| Status | stable |
| Description | The position of the video recording in an album, LP, playlist, top 10 list, podcast history or other ordered list of video recordings. |
| Datatype (pick one) |
|
| Status | stable |
| Description | A link to a sample file or stream of the video recording. |
| Datatype | URL |
| Status | stable |
| Description | A link to a complete video file representation of the video recording. |
| Datatype | URL |
| Status | stable |
| Description | An image summary of the video recording. |
| Datatype | URL |
| Status | stable |
| Description | A genre that should be associated with the video recording. |
| Datatype | plain literal |
| Status | stable |
| Description | The license under which the video recording is distributed. |
| Datatype | URL via rel="license" |
| Status | stable |
| Description | The length of the video recording encoded in ISO-8601 time duration format. |
| Datatype | xsd:duration using ISO-8601 |
| Status | stable |
| Description | Relationship for linking songs to albums, video snippets to podcasts and singular recordings to collections of recordings. |
| Datatype | URI using rel="media:contains" |
| Status | stable |
| Description | A link to a method of paying for a full version of the video recording. |
| Datatype | URL using rel="commerce:payment" |
| Status | stable |
| Description | A link to a method of paying for a full version of the video recording. |
| Datatype | commerce:Price (containing both commerce:currency and commerce:amount) |
Video content consistently share several common fields. Where possible the Video RDF Vocabulary has been based on this minimal common subset.
Fields that are type-specific have been omitted from the Video RDF Vocabulary. It is important that this vocabulary be kept simple and minimal from the start. Additional features can be added as deemed necessary by practical implementation experience.
The concept of a universal video identifier, that is, how to identify the same video album, song, speech, or podcast across different music and video sites, though something very useful to have, is outside the scope of this format.
This vocabulary is the embodiment of a large group effort lead by Digital Bazaar, Inc. and pulls resources from the World Wide Web Consortium, the RDFa community and the Microformats community. It is a world-wide effort in semantic metadata standardization.
If you would like to extend this particular vocabulary, we ask that you engage the community in doing so. History has shown that if there is a wide-spread need for a vocabulary extension, it will be discussed, and agreed upon by the larger community before making it's way into the vocabulary. This process can take as little as a week. Work with us before forging out on your own, the knowledge of the masses are your ally.
This document is copyright 2008 Digital Bazaar, Inc. and is licensed under a Creative Commons Public Domain Dedication.
All ideas and patentable material outlined in the document are hereby dedicated to the public domain. It is our intent that all future additions, modifications and contributions will be dedicated to the public domain as well.
We have released our copyright and control of this vocabulary for the good of the community and the betterment of the world in the name of open standards.
We kindly ask that proper credit is given when using the vocabulary. A line like the following is sufficient:
The Video RDF Vocabulary is an initiative lead by Digital Bazaar, Inc. and collaborated on by a number of people from the Web at large, the World Wide Web Consortium, the RDFa community and the Microformats community.
Many thanks to the various individuals that did research and proposed ideas and discussion related to media info and video info in general. Among the many participants are RodBegbie, Dean Hudson, Tantek Çelik, Mary Hodder, Joshua Kinberg, ChrisMessina, and Lisa Rein. Others include Martin McEvoy, Alexandre Van De Sande, Michael Johnson, Dave Longley, Brian Suda, Ben Wiley Sittler, Scott Reynen, Frances Berriman, James Craig, David Janes, Andy Mabbett, Danny Ayers, Rudy Desjardins, Edward O'Connor, Ryan King, Chris Griego, Brad Hafichuk, Colin Barrett, and Joe Andrieu.
Many thanks as well to Mike Kaply, Ben Adida, Mark Birbeck, Ralph R. Swick, Shane McCarron, Michael Hausenblas, Steven Pemberton, and Mike Linksvayer for guidance with regards to RDFa.
Manu Sporny, Bitmunk - Digital Bazaar, Inc.
Manu Sporny, Martin McEvoy, Alexandre Van De Sande, Michael Johnson, Dave Longley, Brian Suda, Ben Wiley Sittler, Scott Reynen, Frances Berriman, James Craig, David Janes, Andy Mabbett, Danny Ayers, Rudy Desjardins, Edward O'Connor, Ryan King, Chris Griego, Brad Hafichuk, Tantek Çelik, Colin Barrett, Joe Andrieu, Michael Smethurst, Chris Newell, Julian Stahnke, Justin Maxwell, Paul Wilkins and David I. Lehn.