(RFC 4723 published December 2006)

Type name: audio

Subtype name: mobile-xmf

Required parameters: none

Optional parameters:

   revision: Mobile XMF file type revision ID

      revision is the Mobile XMF file type revision ID number from
      the XmfFileTypeRevisionID field of the XMF Meta File format
      2.00. revision is encoded in hex in US-ASCII.

   prl: Playback resource list

      prl contains the playback resources included in all Content
      Description MetaDataItems of the Mobile XMF file.  prl contains
      two-digit hexadecimal numbers representing data bytes from the
      Content Description Meta Data.  Each resource is listed exactly
      once.  A playback resource contains two parts: a prefix and
      data.  prl is a sequence of two-digit hexadecimal numbers
      encoded in US-ASCII.  Thus, prl has an even number of
      hexadecimal digits.

      Example: If the file includes Playback Resource Lists such as
      [00h 01h 00h 02h] and [00h 01h 00h 03h], the corresponding prl
      is 000100020003 containing playback resources 01, 02, and 03
      each with the prefix 00.

   minimum-pr: Minimum playback requirements

      minimum-pr contains the Maximum Instantaneous Resource (MIR)
      values from the first row of all MIR Count Tables corresponding
      to the playback resources listed in prl.  Only the largest
      value from the values of the same resource is chosen.
      minimum-prl is a sequence of two-digit hexadecimal numbers
      encoded in US-ASCII.  Thus, minimum-prl has an even number of
      hexadecimal digits.

      minimum-pr requires the use of prl, and the values in
      minimum-pr must be in the same order as the resources in prl.
      minimum-pr is the more important of minimum-pr and total-pr,
      because it defines the minimum playback requirements.

      Example: If the file includes the first rows of MIR Count
      Tables such as [02h 00h] and [01h 01h] corresponding to the
      above Playback Resource Lists, the corresponding minimum-pr is
      020001.  (02 is the largest of 2 and 1, 00 is the largest of 0,
      and 01 is the largest of 1.)

   total-pr: Total playback requirements

      total-pr contains the MIR values from the last row of all MIR
      Count Tables corresponding to the playback resources listed in
      prl.  Only the largest value from the values of the same
      resource is chosen.  total-pr is a sequence of two-digit
      hexadecimal numbers encoded in US-ASCII.  Thus, total-pr has an
      even number of hexadecimal digits.

      total-pr requires the use of prl, and the values in total-pr
      must be in the same order as the resources in prl.

      Example: If the file includes the last rows of MIR Count Tables
      such as [05h 02h] and [06h 01h] corresponding to the above
      Playback Resource Lists, the corresponding total-pr is 060201.
      (06 is the largest of 5 and 6, 02 is the largest of 2, and 01
      is the largest of 1.)

Encoding considerations:

   mobile-xmf data is binary data and must be encoded for non-binary
   transport; Base64 [9] is suitable for Email.

Security considerations:

   Many synthetic audio compositions have associated intellectual
   property rights.  It is conceivable that the rights owners of
   mobile-xmf content will want to protect their rights by applying
   security mechanisms that prohibit the rendering of the content
   without a legally acquired license to do so.  These mechanisms
   would be applied externally to the Content-Type defined here;
   mobile-xmf content itself is not encrypted internally.  mobile-xmf
   streams do not contain executable content.  Mobile XMF players are
   robust against corrupted mobile-xmf content, because Mobile XMF
   players ignore unidentified content.  prl, minimum-pr, and
   total-pr parameters can be used to represent Mobile DLS playback
   memory requirements for protecting against the excessive usage of
   playback memory.

Interoperability considerations:

   Mobile XMF is a Musical Instrument Digital Interface (MIDI)
   specification developed by MMA and AMEI.  Mobile XMF is based on
   the XMF Meta File Format Specification v2.00 [5,6], which
   standardizes a meta file format for the electronic distribution of
   music.  mobile-xmf data is stored in XMF file format [5,6].

Published specification:

   Mobile XMF Content Format Specification, MMA specification v1.0.,
     RP-42, Los Angeles, CA, USA.  2004.

   Specification is available from:
     http://www.midi.org/about-midi/specshome.shtml

Applications which use this media type:

   mobile-xmf is a synthetic audio format for the flexible
   presentation of SP-MIDI and Mobile DLS instrument data on a wide
   range of playback devices, particularly portable appliances such
   as mobile phones, PDAs, and palmtop computers.

Additional information:

   Magic number(s):

   First twelve bytes:
   \130\115\106\137\062\056\060\060\000\000\000\002

   File extension(s): mxmf

   Macintosh File Type Code(s): mxmf

Person & email address to contact for further information:

   Timo Kosonen
   Email: timo.kosonen&nokia.com

Intended usage: COMMON

Restrictions on usage: none

Authors:

   Timo Kosonen
   Email: timo.Kosonen&nokia.com

   Tom White
   Email: twhite&midi.org

Change controller:

   MIDI Manufacturers Association
   P.O. Box 3173
   La Habra, CA  90632-3173
   Tel (714) 736-9774
   Fax (714) 736-9775
   Point of contact:
   Tom White
   Email: twhite&midi.org