Network Working Group A. Melnikov Internet-Draft Isode Ltd Intended status: Standards Track November 2, 2008 Expires: May 6, 2009 Conversion parameters for IMAP CONVERT draft-melnikov-lemonade-convert-params-02.txt 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/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on May 6, 2009. Abstract This is a companion document to the Lemonade CONVERT (draft-ietf-lemonade-convert-XX.txt) extension. It defines additional conversion parameters for conversions of image/* and text/* body parts. It also demonstrates additional CONVERT usage scenarios. Melnikov Expires May 6, 2009 [Page 1] Internet-Draft IMAP CONVERT parameters November 2008 Table of Contents 1. Requirements notation . . . . . . . . . . . . . . . . . . . . . 3 2. Additional conversion parameters applicable to multiple MIME types . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Additional conversion parameters for image and video conversions . . . . . . . . . . . . . . . . . . . . . . . . . . 3 4. Additional conversion parameters for conversions to text . . . 3 5. Additional conversion parameters for audio and video conversions . . . . . . . . . . . . . . . . . . . . . . . . . . 4 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4 7. Security Considerations . . . . . . . . . . . . . . . . . . . . 4 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 4 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 4 9.1. Normative References . . . . . . . . . . . . . . . . . . . 4 9.2. Informative References . . . . . . . . . . . . . . . . . . 5 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 5 Intellectual Property and Copyright Statements . . . . . . . . . . 6 Melnikov Expires May 6, 2009 [Page 2] Internet-Draft IMAP CONVERT parameters November 2008 1. Requirements notation 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 [RFC2119]. In examples, "C:" and "S:" indicate lines sent by the client and server respectively. If a single "C:" or "S:" label applies to multiple lines, then the line breaks between those lines are for editorial clarity only and are not part of the actual protocol exchange. The five characters [...] means that something has been elided. [[anchor2: Editorial comments and questions are marked like this.]] 2. Additional conversion parameters applicable to multiple MIME types The sizeLimit defines the maximum size (in bytes) of the converted body part. It can be used with any conversion (including the "default conversion"). 3. Additional conversion parameters for image and video conversions Width and heigth of the resulting image can be specified using using the PIX-X and PIX-Y parameters defined in [DISPLAY-FEATURES]. If only one of the parameters is specified, the aspect ratio of the resulting image MUST be maintained. Number of different colors per image pixel (depth) can be controlled by the "color-levels" conversion parameter [DISPLAY-FEATURES]. This would typically be combined with the "color" conversion parameter [DISPLAY-FEATURES], which controls color encoding scheme, such as Mapped (palette or otherwise mapped color), Grey (grey-scale only) or Full (full continuous-tone color) 4. Additional conversion parameters for conversions to text The FORMAT conversion parameter can be used when converting a body part to TEXT/PLAIN. It can contain one of two values: "FLOWED" or "FIXED". When this parameter is not specified the default is "FIXED". This parameter is the most useful when converting from TEXT/HTML. See [RFC3676] for more details on the exact meaning of this conversion parameter. The ExifData conversion parameter can be used when extracting Exif Melnikov Expires May 6, 2009 [Page 3] Internet-Draft IMAP CONVERT parameters November 2008 information in textual format, i.e. when converting a JPEG image to TEXT/PLAIN. It can contain one of two values: "TRUE" or "FALSE". When this parameter is not specified the default value is "FALSE". The resulting TEXT/PLAIN body part is similar in format to the header field section of an email message [RFC5322]. Each header field name is as defined in section 4.6 (4.6.4 D and 4.6.6) of [EXIF] and each value is UTF-8 representation of the corresponding value. 5. Additional conversion parameters for audio and video conversions A conversion may change codec bitrate by specifying the "bitrate" conversion parameter, which is a non-negative integer specifying bits per second. The "encoding-method" conversion parameter can control whether fixed bitrate or variable bitrate encoding is used. It might have one of the two values: "FBR" (for fixed bit rate) or "VBR" (for variable bit rate). For variable bit rate encodings the "min-bit- rate" parameter can also be specified. Its value is a non-negative integer specifying the minimum bits per second. The "frameRate" conversion parameter can specify the maximum frame rate in frames per second, expressed as a rational (>0) number, for example "49/2". 6. IANA Considerations [[anchor8: TBD. Register all new parameters in the IANA registry established by [MEDIAFEAT-REG]]] 7. Security Considerations [[anchor10: TBD]] 8. Acknowledgments [[anchor12: TBD]] 9. References 9.1. Normative References [ABNF] Crocker, D., Ed. and P. Overell, Ed., "Augmented BNF for Syntax Specifications: ABNF", RFC 5234, January 2008. Melnikov Expires May 6, 2009 [Page 4] Internet-Draft IMAP CONVERT parameters November 2008 [EXIF] Japan Electronics and Information Technology Industries Association, "Exchangeable image file format for digital still cameras: Exif Version 2.2", JEITIA 2.2, April 2002. [MEDIAFEAT-REG] Holtman, K., Mutz, A., and T. Hardie, "Media Feature Tag Registration Procedure", BCP 31, RFC 2506, March 1999. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3676] Gellens, R., "The Text/Plain Format and DelSp Parameters", RFC 3676, February 2004. [RFC5322] Resnick, P., Ed., "Internet Message Format", RFC 5322, October 2008. 9.2. Informative References [DISPLAY-FEATURES] Masinter, L., Wing, D., Mutz, A., and K. Holtman, "Media Features for Display, Print, and Fax", RFC 2534, March 1999. [MIME-IMT] Freed, N. and N. Borenstein, "MIME (Multipurpose Internet Mail Extensions) Part Two: Media Types", RFC 2046, November 1996. Author's Address Alexey Melnikov Isode Ltd 5 Castle Business Village 36 Station Road Hampton, Middlesex TW12 2BX UK Email: Alexey.Melnikov@isode.com Melnikov Expires May 6, 2009 [Page 5] Internet-Draft IMAP CONVERT parameters November 2008 Full Copyright Statement Copyright (C) The IETF Trust (2008). 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, THE IETF TRUST 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. 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