The winmidi backend

This backend provides read-write access to the MIDI protocol via the Windows Multimedia API.

It is only available when building for Windows. Care has been taken to keep the configuration syntax similar to the midi backend, but due to differences in the internal programming interfaces, some deviations may still be present.

Global configuration

Option Example value Default value Description
list on off List available input/output devices on startup
detect on off Output channel specifications for any events coming in on configured instances to help with configuration.

Instance configuration

Option Example value Default value Description
read / source 2 none MIDI device to connect for input
write / target DeviceName none MIDI device to connect for output
epn-tx short full Configure whether to clear the active parameter number after transmitting an nrpn or rpn parameter.

Input/output device names may either be prefixes of MIDI device names or numeric indices corresponding to the listing shown at startup when using the global list option.

Channel specification

The winmidi backend supports mapping different MIDI events as MIDIMonster channels. The currently supported event types are

  • cc - Control Changes

  • note - Note On/Off messages

  • pressure - Note pressure/aftertouch messages

  • aftertouch - Channel-wide aftertouch messages

  • pitch - Channel pitchbend messages

  • program - Channel program change messages

  • rpn - Registered parameter numbers (14-bit extension)

  • nrpn - Non-registered parameter numbers (14-bit extension)

A MIDIMonster channel is specified using the syntax channel<channel>.<type><index>. The shorthand ch may be used instead of the word channel (Note that channel here refers to the MIDI channel number).

The pitch, aftertouch and program messages/events are channel-wide, thus they can be specified as channel<channel>.<type>.

MIDI channels range from 0 to 15. Each MIDI channel consists of 128 notes (numbered 0 through 127), which additionally each have a pressure control, 128 CC’s (numbered likewise), a channel pressure control (also called ‘channel aftertouch’) and a pitch control which may all be mapped to individual MIDIMonster channels.

Every MIDI channel also provides rpn and nrpn controls, which are implemented on top of the MIDI protocol, using the CC controls 101/100/99/98/38/6. Both control types have 14-bit IDs and 14-bit values.

Example mappings:

midi1.ch0.note9 > midi2.channel1.cc4
midi1.channel15.pressure1 > midi1.channel0.note0
midi1.ch1.aftertouch > midi2.ch2.cc0
midi1.ch0.pitch > midi2.ch1.pitch
midi2.ch0.nrpn900 > midi1.ch1.rpn1
midi2.ch15.note1 > midi1.ch2.program

Known bugs / problems

Extended parameter numbers (EPNs, the rpn and nrpn control types) will also generate events on the controls (CC 101 through 98, 38 and 6) that are used as the lower layer transport. When using EPNs, mapping those controls is probably not useful.

EPN control types support only the full 14-bit transfer encoding, not the shorter variant transmitting only the 7 high-order bits. This may be changed if there is sufficient interest in the functionality.

Currently, no Note Off messages are sent (instead, Note On messages with a velocity of 0 are generated, which amount to the same thing according to the spec). This may be implemented as a configuration option at a later time.

As this is a Windows-only backend, testing may not be as frequent or thorough as for the Linux / multiplatform backends.