Content Reference Identifier

A Content Reference Identifier or CRID is a concept from the standardization work done by the TV-Anytime forum. It is or closely matches the concept of the Uniform Resource Locator, or URL, as used on the World-Wide Web:

A unit of content, in a broadcast stream, can be referred to by its globally unique CRID in the same way that a webpage can be referred to by its globally unique URL on the web.

A CRID is specified much like URLs. In fact, a CRID is a so-called URI. Typically, the content owner will use their DNS-names in a combination with a product-specific name to create globally unique CRIDs. As an example, let's assume that BBC wanted to make a CRID for the Olympics in China. It may have looked something like this

crid://bbc.co.uk/olympics/2008/

Then, to refer to a specific event - such as the women's shot-put final - they could have used the following inside their metadata.

crid://bbc.co.uk/olympics/2008/final/shotput/women

Currently, three types of CRIDs play a major role in some unidirectional television networks: programme CRID, series CRID, and recommendation CRID.

In web casting

To make the CRID even more globally available the IETF will publish a request for comments specifying the use of the CRID over the web. This will allow consumer devices to hook up to content provider servers, much like current browsers look up webservers, requesting content by CRID.

In May 2005 an Informational RFC, No 4078, was published as the start of this work.

The long-term goal is that CRIDs should be available for use by cell phones, PDAs, digital TV receivers and other consumer devices for fetching content, either from a broadcast stream or over IP-based networks.

References

• RFC 4078 (PDF) Accessed October 27, 2011
• RFC 4078 (TXT) Accessed October 27, 2011
• White, David & Tol, Ronald. "TV-Anytime An adaptation to DVB Transport Streams and Implementation in European Projects" (2009-09-22) Accessed October 28, 2011
• The new TV-Anytime website. Accessed September 21, 2011
• http://www.tv-anytime.org/ Accessed August 26, 2005
• http://tools.ietf.org/html/rfc4078 Accessed August 26, 2005
• NorDig PVR Metadata Whitepaper Version 1.0, Page 11, Section 9.2: "CRID" Accessed September 11, 2011
• NorDig Unified Requirements for Integrated Receiver Decoders for use in cable, satellite, terrestrial and IP-based networks, Page 113, Section 12.4.6: "CRID encoding and reuse" Accessed September 14, 2011
• ETSI TS 102 822-4 V1.5.1 (2010-07), Page 13, Section 8: "CRID" Accessed September 14, 2011
• ETSI TS 102 323 V1.4.1 (2010-01), Page 27, Section 6: "CRIDs and other URIs in DVB networks" Accessed September 14, 2011