MIDI input event listener for Ruby
gem install midi-eye
or using Bundler, add this to your Gemfile
The following is an example that takes any note messages received from a unimidi input, transposes them up one octave and then sends them to an output
First, pick some MIDI IO ports
@input = UniMIDI::Input.gets @output = UniMIDI::Output.gets
Then create a listener for the input port
transpose = MIDIEye::Listener.new(@input)
You can bind an event to the listener using
The listener will try to positively match the parameters you pass in to the properties of the messages it receives.
In this example, we specify that the listener listens for note on/off messages, which are identifiable by their class.
transpose.listen_for(:class => [MIDIMessage::NoteOn, MIDIMessage::NoteOff]) do |event| # raise the note value by an octave event[:message].note += 12 # send the altered note message to the output you chose earlier @output.puts(event[:message]) end
There is also the option of leaving out the parameters altogether and including using conditional if/unless/case/etc statements in the callback.
You can bind as many events to a listener as you wish by repeatedly calling
Once all the events are bound, start the listener
A listener can also be run in a background thread by passing in
:background => true.
transpose.run(:background => true) transpose.join # join the background thread later
- Ari Russo <ari.russo at gmail.com>
Apache 2.0, See the file LICENSE
Copyright (c) 2011-2017 Ari Russo