separate ruby + shell build scripts into their own directories

soundfont-generator/ruby/soundfont_builder.rb

@@ -0,0 +1,205 @@
+#!/usr/bin/env ruby
+#
+# JavaScript Soundfont Builder for MIDI.js
+# Author: 0xFE <mohit@muthanna.com>
+#
+# Requires:
+#
+#   FluidSynth
+#   Lame
+#   OggEnc (from vorbis-tools)
+#   Ruby Gem: midilib
+#
+#   $ brew install fluidsynth vorbis-tools lame (on OSX)
+#   $ gem install midilib
+#
+# You'll need to download a GM soundbank to generate audio.
+#
+# Usage:
+#
+# 1) Install the above dependencies.
+# 2) Edit BUILD_DIR, SOUNDFONT, and INSTRUMENTS as required.
+# 3) Run without any argument.
+
+require 'base64'
+require 'fileutils'
+require 'midilib'
+include FileUtils
+
+BUILD_DIR = "../soundfont"            # Output path
+SOUNDFONT = "./FluidR3_GM.sf2"        # Soundfont file path
+
+# This script will generate MIDI.js-compatible instrument JS files for
+# all instruments in the below array. Add or remove as necessary.
+INSTRUMENTS = [
+  0,     # Acoustic Grand Piano
+  24,    # Acoustic Guitar (nylon)
+  25,    # Acoustic Guitar (steel)
+  26,    # Electric Guitar (jazz)
+  30,    # Distortion Guitar
+  33,    # Electric Bass (finger)
+  34,    # Electric Bass (pick)
+  56,    # Trumpet
+  61,    # Brass Section
+  64,    # Soprano Sax
+  65,    # Alto Sax
+  66,    # Tenor Sax
+  67,    # Baritone Sax
+  73,    # Flute
+  118    # Synth Drum
+]
+
+# The encoders and tools are expected in your PATH. You can supply alternate
+# paths by changing the constants below.
+OGGENC = `which oggenc`.chomp
+LAME = `which lame`.chomp
+FLUIDSYNTH = `which fluidsynth`.chomp
+
+puts "Building the following instruments using font: " + SOUNDFONT
+
+# Display instrument names.
+INSTRUMENTS.each do |i|
+  puts "    #{i}: " + MIDI::GM_PATCH_NAMES[i]
+end
+
+puts
+puts "Using OGG encoder: " + OGGENC
+puts "Using MP3 encoder: " + LAME
+puts "Using FluidSynth encoder: " + FLUIDSYNTH
+puts
+puts "Sending output to: " + BUILD_DIR
+puts
+
+raise "Can't find soundfont: #{SOUNDFONT}" unless File.exists? SOUNDFONT
+raise "Can't find 'oggenc' command" if OGGENC.empty?
+raise "Can't find 'lame' command" if LAME.empty?
+raise "Can't find 'fluidsynth' command" if FLUIDSYNTH.empty?
+raise "Output directory does not exist: #{BUILD_DIR}" unless File.exists?(BUILD_DIR)
+
+puts "Hit return to begin."
+$stdin.readline
+
+NOTES = {
+  "C"  => 0,
+  "Db" => 1,
+  "D"  => 2,
+  "Eb" => 3,
+  "E"  => 4,
+  "F"  => 5,
+  "Gb" => 6,
+  "G"  => 7,
+  "Ab" => 8,
+  "A"  => 9,
+  "Bb" => 10,
+  "B"  => 11
+}
+
+MIDI_C0 = 12
+VELOCITY = 85
+DURATION = Integer(3200 * 0.75)
+TEMP_FILE = "#{BUILD_DIR}/temp.midi"
+
+def note_to_int(note, octave)
+  value = NOTES[note]
+  increment = MIDI_C0 + (octave * 12)
+  return value + increment
+end
+
+def int_to_note(value)
+  raise "Bad Value" if value < MIDI_C0
+  reverse_notes = NOTES.invert
+  value -= MIDI_C0
+  octave = value / 12
+  note = value % 12
+  return { key: reverse_notes[note],
+           octave: octave }
+end
+
+# Run a quick table validation
+MIDI_C0.upto(100) do |x|
+  note = int_to_note x
+  raise "Broken table" unless note_to_int(note[:key], note[:octave]) == x
+end
+
+def generate_midi(program, note_value, file)
+  include MIDI
+  seq = Sequence.new()
+  track = Track.new(seq)
+
+  seq.tracks << track
+  track.events << ProgramChange.new(0, Integer(program))
+  track.events << NoteOn.new(0, note_value, VELOCITY, 0) # channel, note, velocity, delta
+  track.events << NoteOff.new(0, note_value, VELOCITY, DURATION)
+
+  File.open(file, 'wb') { | file | seq.write(file) }
+end
+
+def run_command(cmd)
+  puts "Running: " + cmd
+  `#{cmd}`
+end
+
+def midi_to_audio(source, target)
+  run_command "#{FLUIDSYNTH} -C 1 -R 1 -g 0.5 -F #{target} #{SOUNDFONT} #{source}"
+  run_command "#{OGGENC} -m 32 -M 64 #{target}"
+  run_command "#{LAME} -v -b 8 -B 32 #{target}"
+  rm target
+end
+
+def open_js_file(instrument_key, type)
+  js_file = File.open("#{BUILD_DIR}/#{instrument_key}-#{type}.js", "w")
+  js_file.write(
+"""
+if (typeof(MIDI) === 'undefined') var MIDI = {};
+if (typeof(MIDI.Soundfont) === 'undefined') MIDI.Soundfont = {};
+MIDI.Soundfont.#{instrument_key} = {
+""")
+  return js_file
+end
+
+def close_js_file(file)
+  file.write("\n}\n")
+  file.close
+end
+
+def base64js(note, file, type)
+  output = '"' + note + '": ' 
+  output += '"' + "data:audio/#{type};base64,"
+  output += Base64.strict_encode64(File.read(file)) + '"'
+  return output
+end
+
+def generate_audio(program)
+  include MIDI
+  instrument = GM_PATCH_NAMES[program]
+  program_key = instrument.downcase.gsub(/[^a-z0-9 ]/, "").gsub(/\s+/, "_")
+
+  puts "Generating audio for: " + instrument + "(#{program_key})"
+
+  mkdir_p "#{BUILD_DIR}/#{program_key}-mp3"
+  ogg_js_file = open_js_file(program_key, "ogg")
+  mp3_js_file = open_js_file(program_key, "mp3")
+
+  note_to_int("A", 0).upto(note_to_int("C", 8)) do |note_value|
+    note = int_to_note(note_value)
+    output_name = "#{note[:key]}#{note[:octave]}"
+    output_path_prefix = BUILD_DIR + "/" + output_name
+
+    puts "Generating: #{output_name}"
+    generate_midi(program, note_value, TEMP_FILE)
+    midi_to_audio(TEMP_FILE, output_path_prefix + ".wav")
+
+    puts "Updating JS files..."
+    ogg_js_file.write(base64js(output_name, output_path_prefix + ".ogg", "ogg") + ",\n")
+    mp3_js_file.write(base64js(output_name, output_path_prefix + ".mp3", "mp3") + ",\n")
+
+    mv output_path_prefix + ".mp3", "#{BUILD_DIR}/#{program_key}-mp3"
+    rm output_path_prefix + ".ogg"
+    rm TEMP_FILE
+  end
+
+  close_js_file(ogg_js_file)
+  close_js_file(mp3_js_file)
+end
+
+INSTRUMENTS.each {|i| generate_audio(i)}