This specification defines the stream formats for use with the Encrypted Media Extensions [ENCRYPTED-MEDIA].

Status of This Document

This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at https://www.w3.org/TR/.

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Implementors should be aware that this specification is not stable. Implementors who are not taking part in the discussions are likely to find the specification changing out from under them in incompatible ways. Vendors interested in implementing this specification before it eventually reaches the Candidate Recommendation stage should join the mailing list mentioned below and take part in the discussions.

This document was published by the HTML Media Extensions Working Group as a Working Group Note. If you wish to make comments regarding this document, please send them to public-html-media@w3.org (subscribe, archives). All comments are welcome.

Publication as a Working Group Note does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.

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This document is governed by the 1 September 2015 W3C Process Document.

1. Purpose

This registry is intended to enhance interoperability among implementations and users of encrypted media streams with the Encrypted Media Extensions (EME) specification [ENCRYPTED-MEDIA]. In particular, this registry provides the means (1) to identify and avoid collisions among content type strings, and (2) to disclose information about encrypted data formats accepted by EME implementations to promote interoperability.

2. Organization

The registry maintains a mapping between content type strings and encryption format specifications, which describe the structure, semantics, and processing of the formats. The strings are those used for the media type/subtype pairs in contentType values provided to Encrypted Media Extensions [ENCRYPTED-MEDIA] APIs.

This registry is not intended to include any information on whether a stream format is encumbered by intellectual property claims. Implementors and users are advised to seek appropriate legal counsel in this matter if they intend to implement or use a specific stream format.

3. Registration Entry Requirements

  1. Each entry must include a unique Initialization Data Type string.

  2. Each entry must include a link that references a publicly available specification. It is RECOMMENDED that such a specification be made available without cost (other than reasonable shipping and handling if not available by online means).

  3. Candidate entries must be announced on public-html-media@w3.org(subscribe, archives) so they can be discussed and evaluated for compliance before being added to the registry.

  4. Per the Encrypted Media Extensions specification, the media container for a stream format MUST NOT be encrypted.

  5. Per the Encrypted Media Extensions specification, entries MUST be fully specified and support "common encryption" such that the content can decrypted in a fully specified and compatible way when a key or keys are provided.

4. Registry

MIME type/subtype Public Specification(s)
ISO Common Encryption ('cenc') Protection Scheme for ISO Base Media File Format Stream Format [EME-STREAM-MP4]
WebM Stream Format [EME-STREAM-WEBM]

A. References

A.1 Normative references

David Dorwin; Adrian Bateman; Mark Watson; Jerry Smith. W3C. ISO Common Encryption ('cenc') Protection Scheme for ISO Base Media File Format Stream Format. URL: ../stream/mp4.html
David Dorwin; Adrian Bateman; Mark Watson. W3C. WebM Stream Format. URL: ../stream/webm.html
David Dorwin; Jerry Smith; Mark Watson; Adrian Bateman. W3C. Encrypted Media Extensions. 5 July 2016. W3C Candidate Recommendation. URL: https://www.w3.org/TR/encrypted-media/