Internet Engineering Task Force Audio-Video Transport WG & Others INTERNET-DRAFT D. Singer draft-singer-avt-3gpp-mime-00 Apple Computer Aug 14 2003 Expires: Feb 14 2004 MIME Type Registrations for 3GPP Multimedia files Status of This Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet- Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/1id-abstracts.html The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119. Distribution of this document is unlimited. Abstract This document serves to register and document the standard MIME types associated with the 3GPP multimedia file format [1], which is part of the family of known as the ISO file formats. 1 Introduction The third-generation partnership project (3GPP) for third-generation cellular telephony has defined a standard file to contain D. Singer [Page 1]
Internet Draft draft-singer-avt-3gpp-mime-00 Aug 14 2003 audio/visual sequences which may be downloaded to cellular phones. At the time of writing, this file format can contain H.263 or MPEG-4 video; and AMR Narrow-band or AMR wide-band speech, or AAC audio; and 3GPP timed text. Within the file, as with all files in the 'ISO' family, there is an intrinsic file-type atom, which identifies those specifications to which the file complies, and which players (possibly compliant with only one specification) are permitted by the content author to play the file. This identification is through four-letter 'brands'. Files identified by the MIME type defined here MUST contain a brand defined in a standard issued by 3GPP that can apply to 3GPP files, in their compatible brands list. The MIME types defined here are needed correctly to identify such files when they are served over HTTP, included in multi-part documents, or used in other places where MIME types are used. 3 Security Considerations The 3GPP file format may contain audio, video, and displayable text data. There is currently no provision for 'active' elements (such as scripts) of any kind. Clearly it is possible to author malicious files which attempt to call for an excessively large picture size, high sampling-rate audio etc. However, clients can and usually do protect themselves against this kind of attack. It should be noted that selected metadata fields may encompass information partly intended to protect the media against unauthorized use or distribution. In this case the intention is that alteration or removal of the data in the field would be treated as an offence under national agreements based World Intellection Property Organization (WIPO) treaties. 3GPP files have an extensible structure, so that it is theoretically possible that metadata fields or media formats could be defined in the future which could be used to induce particular actions on the part of the recipient, thus presenting additional security risks, but this type of capability is currently not supported in the referenced specification. There is no current provision in the standards for encryption, signing, or authentication of these file formats. 4 MIME Types D. Singer [Page 2]
Internet Draft draft-singer-avt-3gpp-mime-00 Aug 14 2003 This registration applies to all files defined as using the '3GP' file format and identified with a suitable brand in a 3GPP specification. The usual file suffix for all these files is ".3gp". The type "video/3gpp" is valid for all files. The type "audio/3gpp" MAY only be used for files containing audio but no visual presentation. It is valid to server an audio-only file as "video/3gpp", however. To: ietf-types@iana.org Subject: Registration of Standard MIME media type video/3gpp, audio/3gpp MIME media type name: video or audio MIME subtype name: 3gpp Required parameters: none Optional parameters: none Encoding considerations: files are binary and should be transmitted in a suitable encoding without CR/LF conversion, 7-bit stripping etc.; base64 is a suitable encoding; Security considerations: see above Interoperability considerations: The 3GPP organization and specifications has defined interoperability and conformance, and conducts regular interoperability testing. Published specification: 3GPP 26.234, release 5 or later. 3GPP specifications are publicly accessible at the 3GPP web site, www.3gpp.org. Applications which use this media type: Multi-media Additional information: Magic number(s): None. However, the file-type atom must occur first in the file, and MUST contain a 3GPP brand in its compatible brands list. File extension(s): 3gp and 3gpp are both declared at http://www.nist.gov/nics/; 3gp is preferred Macintosh File Type Code(s): '3gpp' Person & email address to contact for further information: Nokia MIME manager, mime@nokia.com Intended usage: COMMON Change controller: 3GPP 5 IANA Considerations D. Singer [Page 3]
Internet Draft draft-singer-avt-3gpp-mime-00 Aug 14 2003 This document registers the MIME types audio/3gpp and video/3gpp, defined above. Acknowledgments The review of the 3GPP SA4 committee is gratefully acknowledged. D. Singer [Page 4]
Internet Draft draft-singer-avt-3gpp-mime-00 Aug 14 2003 Authors' Contact Information David Singer Apple Computer, Inc. One Infinite Loop, MS:302-3MT Cupertino CA 95014 USA Email: singer@apple.com Tel: +1 408 974 3162 Roberto Castagno Nokia Mobile Phones PO Box 83, FIN-33721 Tampere (Sinitaival 5, FIN-33720 Tampere) Finland Email: roberto.castagno@nokia.com Tel: +358 3 272 5796 6. References [3gpp] 3GPP TS 26.234: Transparent end-to-end packet switched streaming service (PSS); Protocols and codecs. [MIME1] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies", RFC 2045, November 1996. D. Singer [Page 5]
