Sustainability of Digital Formats
 Planning for Library of Congress Collections

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Identification and description

Full name	RIFF-based MIDI File Format (RMID)
Description	Wrapper format for MIDI data, as first specified by Microsoft, and later extended by MIDI.org (an arm of the MIDI Manufacturers Association) to permit the bundling of both MIDI files and Downloadable Sounds (DLS) files.
Production phase	May be used by composers or arrangers for initial-state activities, in middle-state exchange of data or archiving, or for final-state, end-user delivery.
Relationship to other formats
May contain	SMF, Standard MIDI File Format
May contain	DLS, Downloadable Sounds Format

Local use

LC experience or existing holdings	None
LC preference	None established at this time. It is worth noting that after the MIDI Manufacturers Association developed XMF in 2001, they recommend its use in preference to RMID.

Sustainability factors

Disclosure	Fully documented. Initially developed by Microsoft (1991 and before) and extended by MIDI.org (an arm of the MIDI Manufacturers Association).
Documentation	Initial specification as part of the RIFF format in Microsoft Windows Multimedia Programmer's Reference (section 8-31); extended specification available as technical note RP-029, "Bundling SMF and DLS data in an 'RMID' File", from MIDI.org.
Adoption	Not known to the compiler of this document.
Licensing and patent claims	None
Transparency	Transparent wrapper. See also MIDI_SD and DLS.
Self-documentation	Good potential; see RIFF.
External dependencies	See MIDI_SD.
Technical protection considerations	None known to the compilers of this document.

Quality and functionality factors

Normal rendering for sound	Not applicable; see MIDI_SD and DLS
Fidelity (support for high audio resolution)	Not applicable; see MIDI_SD.
Support for multiple sound channels	Not applicable; see MIDI_SD.
Support for downloadable or user-defined sounds, samples, and patches	See DLS
Functionality beyond normal rendering for sound	See MIDI_SD. The compilers of this document have not investigated the degree to which such added functionality is provided by RMID as distinct from other file formats and/or application software.

File type signifiers

Tag type	Value	Note
Filename Extension	rmi	From The File Extension Source.
Internet Media Type	audio/mid	From The File Extension Source. No Internet Media Type listing found at http://www.iana.org/assignments/media-types/.
Magic numbers	Hex: 52 49 46 46 xx xx xx xx 52 4D 49 44 64 61 74 61 ASCII: RIFF....RMIDdata	From Gary Kessler's File Signatures Table.
RIFF form type	RMID

Notes

General

History

The RIFF format specifications were published in 1991 in Microsoft Windows Multimedia Programmer's Reference, with a brief section devoted to RMID (8-31). The extended specification that documented how both MIDI and downloadable sounds could be bundled in an RMID file (technical note RP-029, "Bundling SMF and DLS data in an 'RMID' File"), was published by the MIDI Manusfacturers Association (MMA) in 2000. The co-authors represent IBM Research, Kurzweil, Microsoft, and Sonic Foundry. In 2001, MMA published the XMF specification, which they now prefer to RMID.

Format specifications

URLs
• "Bundling SMF and DLS data in an 'RMID' File" (technical note RP-029) published by the MIDI Manusfacturers Association (http://www.midi.org/about-midi/rp29spec(rmid).pdf)

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• Microsoft Windows Multimedia Programmer's Reference. Redmond, Washington: Microsoft Press, 1991. Section 8-31 is devoted to RMID.

Useful references

URLs
• See MIDI_SD.
• MIDI.org (http://www.midi.org/)
• Gary Kessler's File Signatures Table (http://www.garykessler.net/library/file_sigs.html).
• The File Extension Source (http://filext.com/)

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