Created
June 29, 2013 21:35
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Compiles MML to MIDI
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require_relative 'midifile' | |
TicksPerQuarter = 32 | |
NoteOffsets = { 'c' => 0, 'd' => 2, 'e' => 4, 'f' => 5, 'g' => 7, 'a' => 9, 'b' => 11 } | |
class Track | |
attr_reader :delay, :octave, :note, :velocity, :bytes, :default_delay | |
attr_writer :delay, :octave, :note, :velocity, :bytes, :default_delay | |
def initialize() | |
@delay = 0 | |
@octave = 5 | |
@note = nil | |
@velocity = 0x40 | |
@bytes = [] | |
@default_delay = TicksPerQuarter | |
end | |
end | |
def error(msg) | |
puts msg | |
exit | |
end | |
def add(arr) | |
arr.each { |byte| $midi_bytes << byte } | |
end | |
def track_add(arr) | |
arr.each { |byte| $current_track.bytes << byte } | |
end | |
def parse_line(line) | |
i = 0 | |
while i < line.length | |
if line[i] =~ /[ABCDEFGHIJKLMNOPQRSTUVWXYZ]/ | |
if not $tracks.has_key? line[i] | |
$tracks[line[i]] = Track.new() | |
end | |
$current_track = $tracks[line[i]] | |
i += 1 | |
elsif line[i] == 'l' | |
i += 1 | |
if line[i...line.length] =~ /^(\d+)/ | |
$current_track.default_delay = TicksPerQuarter * 4 / $1.to_i | |
i += $1.length | |
end | |
elsif line[i] =~ /[abcdefg]/ | |
note_val = $current_track.octave * 12 + NoteOffsets[line[i]] | |
i += 1 | |
if line[i] == '+' | |
note_val += 1 | |
i += 1 | |
elsif line[i] == '-' | |
note_val -= 1 | |
i += 1 | |
end | |
if $current_track.note != nil | |
track_add midi_event($current_track.delay, NoteOff, 0, $current_track.note, 0x40) | |
track_add midi_event(0, NoteOn, 0, note_val, $current_track.velocity) | |
else | |
track_add midi_event($current_track.delay, NoteOn, 0, note_val, $current_track.velocity) | |
end | |
$current_track.note = note_val | |
if line[i...line.length] =~ /^(\d+)/ | |
$current_track.delay = TicksPerQuarter * 4 / $1.to_i | |
i += $1.length | |
else | |
$current_track.delay = $current_track.default_delay | |
end | |
dot_count = 0 | |
delay = $current_track.delay | |
while line[i] == '.' | |
dot_count += 1 | |
$current_track.delay += delay / (2 ** dot_count) | |
i += 1 | |
end | |
elsif line[i] == '<' | |
$current_track.octave -= 1 | |
i += 1 | |
elsif line[i] == '>' | |
$current_track.octave += 1 | |
i += 1 | |
elsif line[i] == 'o' | |
i += 1 | |
if line[i...line.length] =~ /^(\d+)/ | |
$current_track.octave = $1.to_i | |
i += $1.length | |
end | |
elsif line[i] == 'v' | |
i += 1 | |
if line[i...line.length] =~ /^(\d+)/ | |
$current_track.velocity = $1.to_i | |
i += $1.length | |
end | |
elsif line[i] == 'r' | |
i += 1 | |
track_add midi_event($current_track.delay, NoteOff, 0, $current_track.note, 0x40) | |
$current_track.note = nil | |
if line[i...line.length] =~ /^(\d+)/ | |
$current_track.delay = TicksPerQuarter * 4 / $1.to_i | |
i += $1.length | |
else | |
$current_track.delay = $current_track.default_delay | |
end | |
delay = $current_track.delay | |
dot_count = 0 | |
while line[i] == '.' | |
dot_count += 1 | |
$current_track.delay += delay / (2 ** dot_count) | |
i += 1 | |
end | |
elsif line[i] == 's' or line[i] == 'w' | |
i += 1 | |
delay = $current_track.default_delay | |
if line[i...line.length] =~ /^(\d+)/ | |
delay = TicksPerQuarter * 4 / $1.to_i | |
i += $1.length | |
end | |
$current_track.delay += delay | |
dot_count = 0 | |
while line[i] == '.' | |
dot_count += 1 | |
$current_track.delay += delay / (2 ** dot_count) | |
i += 1 | |
end | |
elsif line[i...line.length] =~ /^@(\d+)/ | |
track_add midi_event($current_track.delay, ProgramChange, 0, $1.to_i) | |
$current_track.delay = 0 | |
i += $1.length | |
elsif line[i] == 't' | |
i += 1 | |
if line[i...line.length] =~ /^(\d+)/ | |
microseconds = 1000000 / ($1.to_i / 60) | |
arr = int_to_bytes(microseconds, 3) | |
track_add midi_meta_event($current_track.delay, SetTempo, 03, *arr) | |
$current_track.delay = 0 | |
i += $1.length | |
end | |
else | |
i += 1 | |
end | |
end | |
end | |
ARGV.each do |filename| | |
mml_text = '' | |
File.open(filename, 'r') do |file| | |
mml_text = file.read() | |
end | |
$midi_bytes = [] | |
$tracks = {} | |
$tracks['A'] = Track.new() | |
$current_track = $tracks['A'] | |
mml_text.each_line do |line| | |
if line =~ /^#TITLE +(.+)$/ | |
data = [ $1.bytes.length ] | |
$1.each_byte { |byte| data << byte } | |
track_add midi_meta_event(0, TrackName, *data) | |
else | |
parse_line(line) | |
end | |
end | |
add header(MultipleTracksSync, $tracks.length, TicksPerQuarter) | |
for track in $tracks.values | |
$current_track = track | |
track_add midi_meta_event(0, EndTrack, 0) | |
add track_header(track.bytes.length) | |
add track.bytes | |
end | |
str = '' | |
$midi_bytes.each { |byte| str += byte.chr } | |
File.open(filename + '.mid', 'w') do |file| | |
file.write(str) | |
end | |
end |
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