MIDI Parser

Ruby Parser for Raw MIDI Messages

This library is part of a suite of Ruby libraries for MIDI:

This library is based on Ari Russo's library Nibbler.

gem install midi-parser

or using Bundler, add this to your Gemfile

gem "midi-parser"

require 'midi-parser'

midi_parser = MIDIParser.new

Enter a message piece by piece:

midi_parser.parse("90")
  => nil

midi_parser.parse("40")
  => nil

midi_parser.parse("40")
  => #<MIDIEvents::NoteOn:0x98c9818
       @channel=0,
       @data=[64, 100],
       @name="C3",
       @note=64,
       @status=[9, 0],
       @velocity=100,
       @verbose_name="Note On: C3">

Enter a message all at once:

midi_parser.parse("904040")

  => #<MIDIEvents::NoteOn:0x98c9818
        @channel=0,
        @data=[64, 100],
        @name="C3",
        @note=64,
        @status=[9, 0],
        @velocity=100,
        @verbose_name="Note On: C3">

Use bytes:

midi_parser.parse(0x90, 0x40, 0x40)
  => #<MIDIEvents::NoteOn:0x98c9818 ...>

You can use nibbles in string format:

midi_parser.parse("9", "0", "4", "0", "4", "0")
  => #<MIDIEvents::NoteOn:0x98c9818 ...>

Interchange the different types:

midi_parser.parse("9", "0", 0x40, 64)
  => #<MIDIEvents::NoteOn:0x98c9818 ...>

Use running status:

midi_parser.parse(0x40, 64)
  => #<MIDIMEvents::NoteOn:0x98c9818 ...>

Add an incomplete message:

midi_parser.parse("9")
midi_parser.parse("40")

See progress:

midi_parser.buffer
  => ["9", "4", "0"]

midi_parser.buffer_s
  => "940"

MIDI Parser generates midi-events objects.

• (TO DO) rdoc

MIDI Parser is mostly a clone of Nibbler with some modifications:

• Removed logging attributes (messages, rejected, processed) to reduce parsing overhead
• Updated dependencies versions
• Source updated to Ruby 2.7 code conventions (method keyword parameters instead of options = {}, hash keys as 'key:' instead of ':key =>', etc.)
• Changed backend library midi-message to midi-events
• Removed backend library MIDIlib
• Renamed module to MIDIParser instead of Nibbler
• Renamed gem to midi-parser instead of nibbler
• Minor docs fixing
• TODO: update tests to use rspec instead of rake
• TODO: migrate to (or confirm it's working ok on) Ruby 3.0 or Ruby 3.1

The author has been developing since 2016 a Ruby project called Musa DSL that needs a way of representing MIDI Events and a way of communicating with MIDI Instruments and MIDI Control Surfaces.

Ari Russo has done a great job creating several interdependent Ruby libraries that allow MIDI Events representation (MIDI Message and Nibbler) and communication with MIDI Instruments and MIDI Control Surfaces (unimidi, ffi-coremidi and others) that, with some modifications, I've been using in MusaDSL.

After thinking about the best approach to publish MusaDSL I've decided to publish my own renamed version of the modified dependencies because:

• The original libraries have features (buffering, very detailed logging and processing history information, not locking behaviour when waiting input midi messages) that are not needed in MusaDSL and, in fact, can degrade the performance on some use cases in MusaDSL.
• The requirements for Musa DSL users probably will evolve in time, so it will be easier to maintain an independent source code base.
• Some differences on the approach of the modifications vs the original library doesn't allow to merge the modifications on the original libraries.
• Then the renaming of the libraries is needed to avoid confusing existent users of the original libraries.
• Due to some of the interdependencies of Ari Russo libraries, the modification and renaming on some of the low level libraries (ffi-coremidi, etc.) forces to modify and rename unimidi library.

All in all I have decided to publish a suite of libraries optimized for MusaDSL use case that also can be used by other people in their projects.

• Javier Sánchez Yeste

Thanks to Ari Russo for his ruby library Nibbler licensed as Apache License 2.0.

MIDI Parser Copyright (c) 2021 Javier Sánchez Yeste, licensed under LGPL 3.0 License

Nibbler Copyright (c) 2011-2015 Ari Russo, licensed under Apache License 2.0 (see the file LICENSE.nibbler)