Network Working Group P. Frojdh INTERNET-DRAFT U. Lindgren draft-westerlund-mime-dls-01 M. Westerlund Expires: August 2006 Ericsson February 10, 2006 Media Type Registrations for Downloadable Sounds for MIDI Status of this memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. 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.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html This document is an individual submission to the IETF. Comments should be directed to the author. Abstract This document serves to register a media type for Downloadable Sounds. Frojdh, Lindgren and Westerlund [Page 1] INTERNET-DRAFT draft-westerlund-mime-dls-01 February 10, 2006 TABLE OF CONTENTS 1. Conventions Used.................................................3 2. Introduction.....................................................3 3. Security Considerations..........................................3 4. IANA Considerations..............................................4 4.1. Downloadable Sound.............................................4 5. RFC Editor Considerations........................................6 6. Authors' Addresses...............................................6 7. References.......................................................6 7.1. Normative......................................................6 7.2. Informative....................................................7 8. IPR Notice.......................................................7 9. Copyright Notice.................................................7 Frojdh, Lindgren and Westerlund [Page 2] INTERNET-DRAFT draft-westerlund-mime-dls-01 February 10, 2006 1. Introduction The present document seeks to register a media type for Downloadable Sounds (DLS). The DLS format is used to define instruments for widely used wavetable synthesizers associated with the standards [DLS1, DLS2, MDLS]. DLS, and their associated standards are maintained and defined by two organizations, the MIDI Manufacturers Association (MMA) and the Association of the Musical Electronics Industry (AMEI). The media type defined here is needed to correctly identify DLS files when they are served over HTTP, included in multi-part documents, or used in other places where media types are used. 2. Security Considerations The DLS format may contain audio, displayable text data, and modeling parameters (a.k.a. articulation parameters). In addition, the DLS format contains a so-called conditional chunk which is 'active' in the sense that it affects the execution of a DLS file parser. However, the DLS format does not currently define any scripting mechanism. Clearly it is possible to author malicious files which, for example, contain large amounts of data always blocked by a conditional statement, i.e. no synthesizer loads the instruments. However, for DLS, clients can and usually do protect themselves against these kinds of attacks. For DLS content containing conditional chunks it is stressed that the chunk in question is optional, that is to say a parser does not have to execute the chunk. However, if a parser evaluates a conditional chunk, it is still possible to parse its content and draw a conclusion whether or not it is usable for a particular synthesizer engine. It should be noted that selected metadata fields may include 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 on World Intellection Property Organization (WIPO) treaties. DLS have an extensible structure, making it theoretically possible to define metadata fields or media formats in the future which could be used to induce particular actions of the recipient, and thus present additional security risks. However, this type of capability is currently not supported in the referenced specifications. Frojdh, Lindgren and Westerlund [Page 3] INTERNET-DRAFT draft-westerlund-mime-dls-01 February 10, 2006 There is no current provision in the DLS standard for encryption, signing, or authentication within the file formats. 3. IANA Considerations The present document requests that IANA registers the media type audio/dls as specified in Section 3.1. The registration uses the template present in [RFC4288]. 3.1. Media Type for Downloadable Sounds Type name: audio Subtype name: dls Required parameters: none Optional parameters: 'dls-type' A comma-separated list of the dls types (one or more) that the file content conforms to. The following values are specified: 0, 1, and 2 signify Downloadable Sounds Level 1.1b content, Downloadable Sounds Level 2.1 content, and Mobile Downloadable Sound content, respectively. All types that the content conforms to should be indicated. Further values (integers) may be specified in the future, and any unknown values shall be ignored. If the parameter is not specified, it corresponds to a value equal to 0, i.e. the content conforms to Downloadable Sound level 1.1b. Encoding considerations: DLS files are binary and should be transmitted in a suitable encoding without CR/LF conversion, 7-bit stripping etc.; base64 [RFC3548] is a suitable encoding. Security considerations: see the security considerations in section 3 of RFC XXXX. Frojdh, Lindgren and Westerlund [Page 4] INTERNET-DRAFT draft-westerlund-mime-dls-01 February 10, 2006 Interoperability considerations: This media type is for the consumption by a MIDI player capable of utilizing downloadable sounds for its synthesizers. A general purpose audio player will not be capable of utilizing the audio within the format without explicit support of the format. Published specification: Downloadable Sounds Level 1.1b [DLS1], Downloadable Sounds Level 2.1 [DLS2], and Mobile Downloadable Sounds [MDLS]. MMA specifications can be ordered from the MMA web site, www.midi.org. Applications which use this media type: Multi-media Additional information: Magic number(s): The ninth to twelfth bytes of the file must equal (in hexadecimal notation) 44, 4c, 53, and 20, respectively. File extension(s): .dls is declared at http://www.nist.gov/nics Person & email address to contact for further information: Ulf A. Lindgren, ulf.a.lindgren@ericsson.com Intended usage: COMMON Restrictions on usage: None Author: Per Frojdh Ulf A. Lindgren Magnus Westerlund Change controller: MIDI Manufacturers Association http://www.midi.org info@midi.org Frojdh, Lindgren and Westerlund [Page 5] INTERNET-DRAFT draft-westerlund-mime-dls-01 February 10, 2006 4. RFC Editor Considerations The references to RFC XXXX in the media type registration need to be replaced with the actual RFC number when it is issued. Please remove this section before publication as RFC. Authors' Addresses Per Frojdh Ericsson AB Ericsson Research SE-164 80 Stockholm Sweden electronic mail: per.frojdh@ericsson.com Ulf A. Lindgren Ericsson AB Ericsson Research SE-417 56 Goteborg Sweden electronic mail: ulf.a.lindgren@ericsson.com Magnus Westerlund Ericsson AB Ericsson Research SE-164 80 Stockholm Sweden electronic mail: magnus.westerlund@ericsson.com 6. References 6.1. Normative [DLS1] "Downloadable Sounds Level 1.1b", MMA/AMEI specificationv1.1b, Los Angeles, CA, USA, 2004. [DLS2] "Downloadable Sounds Level 2.1", MMA/AMEI specification v1.0, Los Angeles, CA, USA, 2001. [MDLS] "Mobile Downloadable Sounds 1.0", MMA specification v1.0, Los Angeles, CA, USA, 2004. [RFC4288] Freed, N. and J. Klensin, "Media Type Specifications and Registration Procedures", BCP 13, RFC 4288, December 2005. Frojdh, Lindgren and Westerlund [Page 6] INTERNET-DRAFT draft-westerlund-mime-dls-01 February 10, 2006 6.2. Informative [RFC3548] Josefsson, S., "The Base16, Base32, and Base64 Data Encodings", RFC 3548, July 2003. IPR Notice 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. 8. Copyright Notice Copyright (C) The Internet Society (2006). 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. This Internet-Draft expires in August 2006. Frojdh, Lindgren and Westerlund [Page 7]