The Interoperable Master Format (IMF) is a new standard (SMPTE - ST 2067) for the digital distribution of audiovisual content. IMF has been designed to be compliant with ISAN.
For a quick introduction to IMF and the components in relation with ISAN, you can refer to these short video tutorials: Why IMF? What is an IMP? What is a CPL? as well as on the infographic: 4 steps for understanding the future of content distribution .
The practice described in this document is still subject to updates. It is currently under review by a group of major IMF end users and implementers.
Identifying a Distribution Master with ISAN
Distribution Masters SHALL be identified in the ISAN system by an ISAN Version (or V-ISAN).
A Distribution Master is in principle identified by a MEDIA manifestation V-ISAN that identifies for example the compilation of a major content with supplemental material and with the dubbing and subtitles resources. However, in most of the cases a distribution master MAY be identified without ambiguity by just an EDITION variant V-ISAN.
An EDITION variant V-ISAN SHALL always have an ISAN Work (Single or Episode) parent.
A MEDIA manifestation V-ISAN SHALL always have an EDITION variant V-ISAN parent.
To learn more about MEDIA Manifestations V-ISAN and EDITION variants V-ISAN you can refer to: Records, relations and hierarchies in the ISAN Registry.
Storing the ISAN in the CPL
General case
In most situations, and except when the content to identify is a version of a version (refer to the next section), the CPL ContentVersionList element:
- SHALL include exactly one ContentVersion element containing the EDITION variant V-ISAN of the Distribution master.
- SHOULD include exactly one ContentVersion element containing the MEDIA manifestation V-ISAN of the Distribution master.
A ContentVersion element containing a V-ISAN SHOULD conform to the following:
- The ContentVersion/Id element SHALL contain the URN representation of the V-ISAN as specified in IETF RFC 4246 : Uniform Resource Name (URN) Namespace Identifier (NID) for ISAN
- The ContentVersion/LabelText element SHOULD contain the following text:
- For an EDITION variant V-ISAN, LabelText= “EDITION variant V-ISAN (Level 2)”
- For a MEDIA manifestation V-ISAN, LabelText = “MEDIA manifestation V-ISAN (Level 3)”
Example 1:
<ContentVersion>
<Id>URN:ISAN:1881-66C7-3420-6541-9-9F3A-0245-U</Id>
<LabelText>EDITION variant V-ISAN (Level 2)</LabelText>
</ContentVersion>
Example 2:
<ContentVersion>
<Id>URN:ISAN:1881-66C7-3420-6541-9-9F3A-0245-U</Id>
<LabelText> EDITION variant V-ISAN (Level 2)</LabelText>
</ContentVersion>
<ContentVersion>
<Id>URN:ISAN:1881-66C7-3420-6541-9-E3A1-4218-Z</Id>
<LabelText>MEDIA manifestation V-ISAN (Level 3)</LabelText>
</ContentVersion>
Note that a ContentVersion element containing the ISAN Work (or Episode) and the Serie identifier (when applicable) is not required as this information is already contained in the structure of all ISAN/V-ISAN. For more information see What is the structure of ISAN?
Special case: the content to identify is a version of a version
An EDITION variant V-ISAN can in occasional cases (e.g. localized versions), be declined into several child EDITION variant V-ISANs identifying each distinct changes, such as localized cuts, music changes or image replacements, applied to the parent variant.
In such special cases, parent and child EDITION Variant V-ISAN SHALL be referenced in the CPL. Consequently, the ContentVersionList element:
- SHALL include exactly one ContentVersion element containing the Parent EDITION variant V-ISAN of the Distribution master.
- SHALL include exactly one ContentVersion element containing the Child EDITION variant V-ISAN of the Distribution master.
- SHOULD include exactly one ContentVersion element containing the MEDIA manifestation V-ISAN of the Distribution master.
A ContentVersion element containing an V-ISAN SHOULD conform to the following:
- The ContentVersion/Id element SHALL contain the URN representation of the V-ISAN as specified in IETF RFC 4246 : Uniform Resource Name (URN) Namespace Identifier (NID) for ISAN
- The ContentVersion/Label Text element SHOULD contain the following text:
Note that a Child EDITION variant V-ISAN can have its own children EDITION variants; this can be repeated as many times as required to identify accurately the content. When multiple versions of versions apply, all ancestors of the last Child EDITION variant V-ISAN SHALL be referenced in the ContentVersionList ordered from the first parent to the last child. The MEDIA manifestation V-ISAN SHALL always have the last Child EDITION variant V-ISAN as parent.
Example 1:
<ContentVersion>
<Id>URN:ISAN:1881-66C7-3420-6541-9-9F3A-0245-U</Id>
<LabelText>EDITION variant V-ISAN (Level 2)</LabelText>
</ContentVersion>
<ContentVersion>
<Id>URN:ISAN:1881-66C7-3420-6541-9-9F3A-0246-S</Id>
<LabelText>Child EDITION variant V-ISAN (Level 2)</LabelText>
</ContentVersion>
Example 2:
<ContentVersion>
<Id>URN:ISAN:1881-66C7-3420-6541-9-9F3A-0245-U</Id>
<LabelText>EDITION variant V-ISAN (Level 2)</LabelText>
</ContentVersion>
<ContentVersion>
<Id>URN:ISAN:1881-66C7-3420-6541-9-9F3A-0246-S</Id>
<LabelText>Child EDITION variant V-ISAN (Level 2)</LabelText>
</ContentVersion>
<ContentVersion>
<Id>URN:ISAN:1881-66C7-3420-6541-9-E3A1-4218-Z</Id>
<LabelText>MEDIA manifestation V-ISAN (Level 3)</LabelText>
</ContentVersion>
Resolving ISAN (and V-ISAN) identifiers
ISAN (and V-ISAN) identifiers can be registered, searched and looked-up in the ISAN Registry with the help of the ISAN Rest API. Contact ISAN-IA (cs@isan.org)for more information and credentials.
Links & notes
The reader of this article is supposed to be familiar with the following ISAN documents:
- ISAN User Guide
- ISAN Data Fields & ISAN Data Fields Appendix - List of Codes
- Applying ISAN to versions of audiovisual works
- IETF RFC 4246 : Uniform Resource Name (URN) Namespace Identifier (NID) for ISAN
Note: The term ISAN can refer to work identifiers or version identifiers (V-ISAN)