





Network Working Group                                        R. Castagno
Request for Comments: 3839                           Nokia Mobile Phones
Category: Standards Track                                      D. Singer
                                                    Apple Computer, Inc.
                                                               July 2004


                      MIME Type Registrations for
      3rd Generation Partnership Project (3GPP) Multimedia files

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2004).

Abstract

   This document serves to register and document the standard MIME types
   associated with the 3GPP multimedia file format, which is part of the
   family based on the ISO Media File Format.

1.  Introduction

   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 BCP 14, RFC 2119
   [RFC2119].

   The third-generation partnership project (3GPP) for third-generation
   cellular telephony has defined a standard file format to contain
   audio/visual sequences which may be downloaded to cellular phones
   [3GPP].  At the time of writing, the 3GPP file format (3GP) can
   contain H.263 or MPEG-4 video, and AMR Narrow-band speech, 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 box, 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'.




Castagno & Singer           Standards Track                     [Page 1]

RFC 3839            MIME Type Registrations for 3GPP           July 2004


   Files identified by the MIME [MIME1] 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 to correctly identify such
   files when they are served over HTTP, included in multi-part
   documents, or used in other places where MIME types are used.

2.  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 offense
   under national agreements based on World Intellectual 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.
   However, 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.

3.  MIME Types

   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".

3.1.  Files with audio but no video

   The type "audio/3gpp" may be used for files containing audio but no
   visual presentation (neither video nor timed text, for example).





Castagno & Singer           Standards Track                     [Page 2]

RFC 3839            MIME Type Registrations for 3GPP           July 2004


   To: ietf-types@iana.org
   Subject: Registration of Standard MIME media type audio/3gpp

MIME media type name:              audio
MIME subtype name:                 3gpp
Required parameters:               none
Optional parameters:               none
                                    Ongoing work related to this
                                    registration may introduce new
                                    optional parameters.  One example
                                    area of effort may introduce a
                                    parameter that would allow for
                                    codecs in use within the MIME type
                                    to be asserted and determined
                                    without examination of the file.
                                    Those with interests in the area
                                    should monitor registrations for
                                    updates.
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.  Note that this MIME type
                                    is used only for files; separate
                                    types are used for real-time
                                    transfer, such as for the RTP
                                    payload format for AMR audio
                                    [RFC3267].
Security considerations:           see the security considerations
                                    section in RFC 3839
Interoperability considerations:   The 3GPP organization has defined the
                                    specification, interoperability, and
                                    conformance, and conducts regular
                                    interoperability testing.
Published specification:           3GPP 26.234, Release 5; 3GPP 26.244,
                                    Release 6 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:            The type "audio/3gpp" MAY be used for
                                    files containing audio but no visual
                                    presentation.  Files served under
                                    this type MUST NOT contain any
                                    visual material. (Note that 3GPP
                                    timed text is visually presented
                                    and is considered to be visual
                                    material).



Castagno & Singer           Standards Track                     [Page 3]

RFC 3839            MIME Type Registrations for 3GPP           July 2004


Magic number(s):                   None.  However, the file-type box
                                    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

3.2.  Any files

   The type "video/3gpp" is valid for all files.  It is valid to serve
   an audio-only file as "video/3gpp".

   To: ietf-types@iana.org
   Subject: Registration of Standard MIME media type video/3gpp

MIME media type name:              video
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.  Note that this MIME type
                                    is used only for files; separate
                                    types are used for real-time
                                    transfer, such as for the RTP
                                    payload formats for H.263
                                    [RFC2429] and AMR audio
                                    [RFC3267].
Security considerations:           see the security considerations
                                    section in RFC 3839
Interoperability considerations:   The 3GPP organization has defined the
                                    specification, interoperability, and
                                    conformance, and conducts regular
                                    interoperability testing.
Published specification:           3GPP 26.234, Release 5; 3GPP 26.244,
                                    Release 6 or later.  3GPP
                                    specifications are publicly
                                    accessible at the 3GPP web site,
                                    www.3gpp.org.
Applications which use this media type: Multi-media



Castagno & Singer           Standards Track                     [Page 4]

RFC 3839            MIME Type Registrations for 3GPP           July 2004


Additional information:
Magic number(s):                   None.  However, the file-type box
                                    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

4.  IANA Considerations

   This document registers the MIME types audio/3gpp and video/3gpp,
   defined above.

5.  Acknowledgments

   The review of the 3GPP SA4 committee is gratefully acknowledged, in
   particular Per Frojdh.  The chairs of the AVT working group, in
   particular Colin Perkins, have provided both excellent guidance and
   feedback, for which the authors are grateful.

6.  References

6.1.  Normative References

   [3GPP]    Published specifications in releases 5 and 6:  Release 5:
             3GPP TS 26.234: Transparent end-to-end packet switched
             streaming service (PSS); Protocols and codecs.  Release 6:
             3GPP TS 26.244: Transparent end-to-end packet switched
             streaming service (PSS); 3GPP file format (3GP)

   [MIME1]   Freed, N. and N. Borenstein, "Multipurpose Internet Mail
             Extensions (MIME) Part One: Format of Internet Message
             Bodies", RFC 2045, November 1996.

   [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
             Requirement Levels", BCP 14, RFC 2119, March 1997.









Castagno & Singer           Standards Track                     [Page 5]

RFC 3839            MIME Type Registrations for 3GPP           July 2004


6.2.  Informative References

   [RFC2429] Bormann, C., Cline, L., Deisher, G., Gardos, T., Maciocco,
             C., Newell, D., Ott, J., Sullivan, G., Wenger, S. and C.
             Zhu, "RTP Payload Format for the 1998 Version of ITU-T Rec.
             H.263 Video (H.263+)", RFC 2429, October 1998.

   [RFC3267] Sjoberg, J., Westerlund, M., Lakaniemi, A. and Q. Xie,
             "Real-Time Transport Protocol (RTP) Payload Format and File
             Storage Format for the Adaptive Multi-Rate (AMR) and
             Adaptive Multi-Rate WideBand (AMR-WB) Audio Codecs", RFC
             3267, June 2002.

7.  Authors' Contact Information

   Roberto Castagno
   Nokia Mobile Phones
   PO Box 88, FIN-33721 Tampere
   (Tieteenkatu 1, FIN-33720 Tampere)
   Finland

   Phone: +358 7180 35796
   EMail: roberto.castagno@nokia.com


   David Singer
   Apple Computer, Inc.
   One Infinite Loop, MS:302-3MT
   Cupertino  CA 95014
   USA

   Phone: +1 408 974 3162
   EMail: singer@apple.com


















Castagno & Singer           Standards Track                     [Page 6]

RFC 3839            MIME Type Registrations for 3GPP           July 2004


8.  Full Copyright Statement

   Copyright (C) The Internet Society (2004).  This document is subject
   to the rights, licenses and restrictions contained in BCP 78, and
   except as set forth therein, the authors retain all their rights.

   This document and the information contained herein are provided on an
   "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
   OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
   ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
   INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
   INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
   WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Intellectual Property

   The IETF takes no position regarding the validity or scope of any
   Intellectual Property Rights or other rights that might be claimed to
   pertain to the implementation or use of the technology described in
   this document or the extent to which any license under such rights
   might or might not be available; nor does it represent that it has
   made any independent effort to identify any such rights.  Information
   on the procedures with respect to rights in RFC documents can be
   found in BCP 78 and BCP 79.

   Copies of IPR disclosures made to the IETF Secretariat and any
   assurances of licenses to be made available, or the result of an
   attempt made to obtain a general license or permission for the use of
   such proprietary rights by implementers or users of this
   specification can be obtained from the IETF on-line IPR repository at
   http://www.ietf.org/ipr.

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights that may cover technology that may be required to implement
   this standard.  Please address the information to the IETF at ietf-
   ipr@ietf.org.

Acknowledgement

   Funding for the RFC Editor function is currently provided by the
   Internet Society.









Castagno & Singer           Standards Track                     [Page 7]

