(last updated 2007-01-30)

Type name: audio 

Subtype name: sp-midi 

Required parameters: none 

Optional parameters: none 
 
Encoding considerations: 
 
   sp-midi data is binary data and must be encoded for non-binary 
   transport; Base64 is suitable for Email. 
 
Security considerations: 
 
   Many synthetic audio compositions have associated intellectual 
   property rights.  It is conceivable that the rights owners of sp-
   midi 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; sp-
   midi content itself is not encrypted internally.  sp-midi streams 
   do not contain executable content.  sp-midi players are robust 
   against corrupted sp-midi content, because sp-midi players ignore 
   unidentified content.

Interoperability considerations: 
 
   Scalable Polyphony MIDI (SP-MIDI) is a Musical Instrument Digital 
   Interface (MIDI) specification developed by MMA and AMEI.  SP-MIDI 
   is based on the MIDI 1.0 specification [n3], which standardizes a 
   protocol for the electronic transmission of music performance data 
   suitable for communication between a transmitter and receiver 
   using MIDI messages.  SP-MIDI data is stored in Standard MIDI 
   Files (SMF) [n3]. 
    
   The SP-MIDI format [n1] provides a scalable representation of MIDI 
   content enabling broadly interoperable music applications.  SP-
   MIDI files have encoded information about playback requirements 
   allowing SP-MIDI playback devices with different device 
   capabilities to play the same content according to the composer's 
   polyphony requirements and Channel priority order definitions.  
   SP-MIDI player requirements are specified in separate SP-MIDI 
   profile specifications [n2] defining the supported MIDI messages 
   and device requirement.  All SP-MIDI profiles follow the 
   definitions of the SP-MIDI specification [n1]. 
    
   MMA and AMEI have previously defined the General MIDI (GM) system 
   standards GM1 [i4] GM2 [i5], and GML [i6].  These specifications 
   are technically related to the SP-MIDI specification, but do not 
   support polyphony scalability.  Due to the differences between GM 
   and SP-MIDI systems, GM synthesizers do not support all SP-MIDI 
   content.  Likewise, not all SP-MIDI synthesizers support all GM 
   content.  Thus, a separate MIME definition is needed to 
   distinguish SP-MIDI from the informally used audio/midi content. 
    
Published specification: 
 
   Scalable Polyphony MIDI Specification.  December 2001, RP-034, 
      The MIDI Manufacturers Association, Los Angeles, CA, USA. 
    
   Specification is available from: 
      http://www.midi.org/about-midi/specshome.shtml 
    
Applications which use this media type: 
 
   SP-MIDI is a synthetic audio format for the flexible presentation 
   of MIDI 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 four bytes (1-4): \115\124\150\144,  
      byte (24): \360,  
      byte (26): \177,  
      bytes (28-29): \013\001  
 
   File extension(s): mid  
 
   Macintosh File Type Code(s): Midi  
 
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 

(file created 2007-01-30)
