Class: MIDIMessage::Parser

Inherits:
Object
  • Object
show all
Defined in:
lib/midi-message/parser.rb

Overview

Very simple parsing for more advanced parsing check out nibbler

Instance Method Summary collapse

Constructor Details

#initialize(*args) ⇒ Parser

Can take either a hex string eg Parser.new(“904040”) or bytes eg Parser.new(0x90, 0x40, 0x40) or an array of bytes eg Parser.new([0x90, 0x40, 0x40])



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# File 'lib/midi-message/parser.rb', line 10

def initialize(*args)
  @data = case args.first
          when Array then args.first
          when Numeric then args 
          when String then TypeConversion.hex_string_to_numeric_byte_array(args.first)
          end
end

Instance Method Details

#parse ⇒ Object

Parse the data and return a message



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# File 'lib/midi-message/parser.rb', line 19

def parse
  first_nibble = ((@data.first & 0xF0) >> 4)
  second_nibble = (@data.first & 0x0F)
  case first_nibble
  when 0x8 then NoteOff.new(second_nibble, @data[1], @data[2])
  when 0x9 then NoteOn.new(second_nibble, @data[1], @data[2])
  when 0xA then PolyphonicAftertouch.new(second_nibble, @data[1], @data[2])
  when 0xB then ControlChange.new(second_nibble, @data[1], @data[2])
  when 0xC then ProgramChange.new(second_nibble, @data[1])
  when 0xD then ChannelAftertouch.new(second_nibble, @data[1])
  when 0xE then PitchBend.new(second_nibble, @data[1], @data[2])
  when 0xF then case second_nibble
    when 0x0 then SystemExclusive.new(*@data)
    when 0x1..0x6 then SystemCommon.new(second_nibble, @data[1], @data[2])
    when 0x8..0xF then SystemRealtime.new(second_nibble)
    else nil
    end
  else nil
  end
end