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Network Working Group                                             Y. LimRequest for Comments: 4337                                   net&tv Inc.Category: Standards Track                                      D. Singer                                                          Apple Computer                                                              March 2006MIME Type Registration for MPEG-4Status 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 (2006).Abstract   This document defines the standard MIME types associated with MP4   files.  It also recommends use of registered MIME types according to   the type of contents.Table of Contents1. Introduction ....................................................22. Selection of MIME Types for MP4 Files ...........................33. IANA Considerations .............................................33.1. MP4 File ...................................................43.2. MP4 File with Audio but without Visual Presentation ........5      3.3. MP4 File with MPEG-4 System Stream and neither           Visual nor Audio Presentation ..............................63.4. Initial Object Descriptor (IOD) in Binary Format ...........73.5. Initial Object Descriptor (IOD) in Textual Format ..........84. Security Considerations .........................................95. Acknowledgements ................................................96. Normative References ............................................9Lim & Singer                Standards Track                     [Page 1]

RFC 4337                   MPEG-4 MIME Types                  March 20061.  Introduction   This document describes a standard definition of MIME types   associated with MP4 files and the guidelines for using them.   MPEG-4 (ISO/IEC 14496) is a standard designed for the representation   and delivery of multimedia information over a variety of transport   protocols [1].  It includes interactive scene management and visual   and audio representations, as well as system functionality like   multiplexing, synchronization, and an object descriptor framework   [2].   The historical approach for MPEG data has been to declare it under   "video", and this approach is followed for ISO/IEC 14496.  In   addition, some MIME types are defined under "audio" and "application"   for the streams not containing visual presentation.   Amendment 1 of the ISO/IEC 14496 standard (also known as version 2)   introduced a standard file type, called MP4 files, for encapsulating   ISO/IEC 14496 data.  This is now separately specified as the MP4 file   format [4], which in turn is based on the ISO base media file format   [3].  A separate specification [5] covers the storage of Advanced   Video Coding (AVC) (also known as H.264) [6] material in files based   on the ISO base media file format.  The MP4 file type can be used in   a number of ways; perhaps the most important of these is its use as   an interchange format for ISO/IEC 14496 data, as a content-download   format, and as the format read by streaming media servers.   These first two uses will be greatly facilitated if there is a   standard MIME type for serving these files (e.g., over HTTP).   The ISO/IEC 14496 standard is broad, and therefore the type of data   that may be in such a file can vary.  In brief, simple compressed   video and audio (using a number of different compression algorithms)   can be included; interactive scene information; meta-data about the   presentation; references to ISO/IEC 14496 media streams outside the   file and so on.  Different top-level MIME types are used to identify   the type of the contents in the file.Lim & Singer                Standards Track                     [Page 2]

RFC 4337                   MPEG-4 MIME Types                  March 20062.  Selection of MIME Types for MP4 Files   The MIME types to be assigned to MP4 files are selected according to   the contents.  Basic guidelines for selecting MIME types are as   follows:   a) if the file contains neither visual nor audio presentations, but      only, for example, MPEG-J or MPEG-7, use application/mp4;   b) for all other files, including those that have MPEG-J, etc., in      addition to video or audio streams, video/mp4 should be used;      however:   c) for files with audio but no visual aspect, including those that      have MPEG-J, etc., in addition to audio streams, audio/mp4 may be      used.   In any case, these indicate files conforming to the "MP4"   specification, ISO/IEC 14496-1:2000, systems file format.3.  IANA Considerations   This section describes the MIME types and names to be used with   various MPEG-4 contents.  Sections from 4.1 to 4.5 register five new   MIME types with the IANA.Lim & Singer                Standards Track                     [Page 3]

RFC 4337                   MPEG-4 MIME Types                  March 20063.1.  MP4 File   MIME media type name: video   MIME subtype name: mp4   Required parameters: none   Optional parameters: none   Encoding considerations: base64 IS generally preferred; files are      binary and should be transmitted without CR/LF conversion, 7-bit      stripping, etc.   Security considerations: Seesection 5 of RFC 4337.   Interoperability considerations: A number of interoperating      implementations exist within the ISO/IEC 14496 community, and that      community has reference software for reading and writing the file      format.   Published specification: ISO/IEC 14496-1:2001.   Applications: Multimedia   Additional information:      Magic number(s): none      File extension(s): mp4 and mpg4 are both declared at         <http://pitch.nist.gov/nics/>.      Macintosh File Type Code(s): mpg4 is registered with Apple.   Person to contact for info: David Singer, singer@apple.com   Intended usage: Common   Author/Change controller: David Singer, ISO/IEC 14496 file format      chairLim & Singer                Standards Track                     [Page 4]

RFC 4337                   MPEG-4 MIME Types                  March 20063.2.  MP4 File with Audio but without Visual Presentation   MIME media type name: audio   MIME subtype name: mp4   Required parameters: none   Optional parameters: none   Encoding considerations: base64 IS generally preferred; files are      binary and should be transmitted without CR/LF conversion, 7-bit      stripping, etc.   Security considerations: Seesection 5 of RFC 4337.   Interoperability considerations: A number of interoperating      implementations exist within the ISO/IEC 14496 community, and that      community has reference software for reading and writing the file      format.   Published specification: ISO/IEC 14496-1:2001.   Applications: Multimedia   Additional information:      Magic number(s): none      File extension(s): mp4 and mpg4 are both declared at         <http://pitch.nist.gov/nics/>.      Macintosh File Type Code(s): mpg4 is registered with Apple.   Person to contact for info: David Singer, singer@apple.com   Intended usage: Common   Author/Change controller: David Singer, ISO/IEC 14496 file format      chair.Lim & Singer                Standards Track                     [Page 5]

RFC 4337                   MPEG-4 MIME Types                  March 20063.3.  MP4 File with MPEG-4 System Stream and neither Visual nor      Audio Presentation   MIME media type name:application   MIME subtype name: mp4   Required parameters: none   Optional parameters: none   Encoding considerations: base64 IS generally preferred; files are      binary and should be transmitted without CR/LF conversion, 7-bit      stripping, etc.   Security considerations: Seesection 5 of RFC 4337.   Interoperability considerations: A number of interoperating      implementations exist within the ISO/IEC 14496 community, and that      community has reference software for reading and writing the file      format.   Published specification: ISO/IEC 14496-1:2001.   Applications: Multimedia   Additional information:      Magic number(s): none      File extension(s): mp4 and mpg4 are both declared at         <http://pitch.nist.gov/nics/>.      Macintosh File Type Code(s): mpg4 is registered with Apple.   Person to contact for info: David Singer, singer@apple.com   Intended usage: Common   Author/Change controller: David Singer, ISO/IEC 14496 file format      chairLim & Singer                Standards Track                     [Page 6]

RFC 4337                   MPEG-4 MIME Types                  March 20063.4.  Initial Object Descriptor (IOD) in Binary Format   MIME media type name: application   MIME subtype name: mpeg4-iod   Required parameters: none   Optional parameters: none   Encoding considerations: base64 is generally preferred; files are      binary and should be transmitted without CR/LF conversion, 7-bit      stripping, etc.   Security considerations: Seesection 5 of RFC 4337.   Interoperability considerations: A number of interoperating      implementations exist within the ISO/IEC 14496 community, and that      community has reference software for reading and writing the file      format.   Published specification: ISO/IEC 14496-1:2001      Applications: Multimedia      Additional information:      Magic number(s): none      File extension(s): none mp4 and mpg4 are both declared at         <http://pitch.nist.gov/nics/>.      Macintosh File Type Code(s): mpg4 is registered with Apple.   Person to contact for info: David Singer, singer@apple.com   Intended usage: Common   Author/Change controller: David Singer, ISO/IEC 14496 file format      chairLim & Singer                Standards Track                     [Page 7]

RFC 4337                   MPEG-4 MIME Types                  March 20063.5.  Initial Object Descriptor (IOD) in Textual Format   MIME media type name: application   MIME subtype name: mpeg4-iod-xmt   Required parameters: none   Optional parameters: none   Encoding considerations: none   Security considerations: Seesection 5 of RFC 4337.   Interoperability considerations: A number of interoperating      implementations exist within the ISO/IEC 14496 community, and that      community has reference software for reading and writing the file      format.   Published specification: ISO/IEC 14496-1:2001 AMD2.   Applications: Multimedia   Additional information:      Magic number(s): none      File extension(s): mp4 and mpg4 are both declared at         <http://pitch.nist.gov/nics/>.      Macintosh File Type Code(s): mpg4 is registered with Apple.   Person to contact for info: David Singer, singer@apple.com   Intended usage: Common   Author/Change controller: David Singer, ISO/IEC 14496 file format      chairLim & Singer                Standards Track                     [Page 8]

RFC 4337                   MPEG-4 MIME Types                  March 20064.  Security Considerations   It is possible to inject non-compliant MPEG streams (Audio, Video,   and Systems) in the MP4 file to overload the receiver/decoder's   buffers.  This might compromise the functionality of the receiver or   even crash it.  This is especially true for end-to-end systems like   MPEG, where the buffer models are precisely defined.   An MP4 file supports the storage of stream types, including commands   that are executed on the terminal such as OD command and BIFS   commands, and programmatic content such as MPEG-J (Java(TM) Byte   Code) and ECMASCRIPT.  It is possible to use one or more of the above   in a manner non-compliant to MPEG to crash the receiver or   temporarily make it unavailable.   Authentication mechanisms can be used to validate of the sender and   the data to prevent security problems due to non-compliant malignant   MP4 files.   A security model is defined in ISO/IEC 14496 Systems MP4 files   containing MPEG-J contents that comprises Java(TM) classes and   objects.  MPEG-J defines a set of Java(TM) APIs and a secure   execution model.  MPEG-J content can call this set of APIs and   Java(TM) methods from a set of Java packages supported in the   receiver within the defined security model.  According to this   security model, downloaded byte code is forbidden to load libraries,   to define native methods, to start programs, to read or write files,   or to read system properties.5.  Acknowledgements   This document has benefited greatly by contributions from many   people, including Mike Coleman, Jean-Claude Duford, Viswanathan   Swaminathan, Peter Westerink, Carsten Herpel, Olivier Avaro, Paul   Christ, Zvi Lifshitz, and many others.  Their insight, foresight, and   contribution is gratefully acknowledged.  Little has been invented   here by the author; this is mostly a collation of greatness that has   gone before.6.  Normative References   [1]  Schulzrinne, H.,  Casner, S., Frederick, R., and V. Jacobson,        "RTP: A Transport Protocol for Real-Time Applications", STD 64,RFC 3550, July 2003.   [2]  ISO/IEC 14496-1 "Information technology - Coding of audio-visual        objects - Part 1 : Systems", 3rd ed. 2004.Lim & Singer                Standards Track                     [Page 9]

RFC 4337                   MPEG-4 MIME Types                  March 2006   [3]  ISO/IEC 14496-12 "Information technology - Coding of audio-        visual objects - Part 12 : ISO Base Media File Format", December        2003.   [4]  ISO/IEC 14496-14 "Information technology - Coding of audio-        visual objects - Part 14 : MP4 File Format", January 2004.   [5]  ISO/IEC 14496-15 "Information technology - Coding of audio-        visual objects - Part 15 : AVC File Format", 2004.   [6]  ISO/IEC 14496-10:2004 "Information technology -- Coding of        audio-visual objects -- Part 10: Advanced Video Coding", 2nd        edition, 2004.Authors' Addresses   Young-Kwon LIM   net&tv Inc.   Room 802 Hanseo Building   1582-6 Seocho-3-Dong Seocho-Gu   Seoul, 137-875, Korea   Phone: +82-2-581-2305   EMail: young@netntv.co.kr   David Singer   Apple Computer, Inc.   One Infinite Loop, MS:302-3MT   Cupertino  CA 95014   USA   Phone: +1 408 974 3162   EMail: singer@apple.comLim & Singer                Standards Track                    [Page 10]

RFC 4337                   MPEG-4 MIME Types                  March 2006Full Copyright Statement   Copyright (C) The Internet Society (2006).   This document is subject to the rights, licenses and restrictions   contained inBCP 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 inBCP 78 andBCP 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 athttp://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 provided by the IETF   Administrative Support Activity (IASA).Lim & Singer                Standards Track                    [Page 11]