The MIDI Mapper

The MIDI Mapper's standard patch services provide device-independent MIDI file playback for applications. The MIDI Mapper can be used with the MCI MIDI sequencer or with low-level MIDI output services.

Unless stated otherwise, all references to MIDI channel numbers use the logical channel numbers 1 through 16. These logical channel numbers correspond to the physical channel numbers 0 through 15 that are actually part of the MIDI message. All references to MIDI program-change and key values use the physical values 0 through 127. All numbers are decimal unless preceded by "0x" prefix, in which case they are hexadecimal.

In the discussion of the MIDI Mapper, the term source refers to the input side of the MIDI Mapper. The term destination refers to the output side of the MIDI Mapper. For example, a source channel is the MIDI channel of a message sent to the MIDI Mapper, and a destination channel is the MIDI channel of a message sent from the MIDI Mapper to an output device.