LMMS/ffmpeg export script (crystal)

export.cr

full_name = ARGV[0]

puts "Input: #{full_name}"

raise "Provide name without file extension or the mmpz file" if /\.(mp3|ogg|wav)\z/ === full_name

name = full_name.sub(/\.mmpz\z/, "")

puts "MP3: #{name}.mp3"
puts "OGG: #{name}.ogg"

# channel = Channel(String).new

o = STDOUT

lmms_args = [
  "-r", "#{name}.mmpz",
  "-o", "#{name}.wav",
  "-b", "256",
  "-i", "sincbest",
]

s = Process.run("lmms", lmms_args, output: o, error: o)

raise "export of #{name}.mmpz failed" if !s.success?

ffmpeg_args = [
  "-i", "#{name}.wav",
  "-ar", "44100",
  "-ac", "2",
  "-b:a", "256k",
]

p1 = Process.fork do
  Process.run("ffmpeg", ffmpeg_args + ["#{name}.mp3"], output: o, error: o)
end

p2 = Process.fork do
  Process.run("ffmpeg", ffmpeg_args + ["#{name}.ogg"], output: o, error: o)
end

[p1, p2].each(&.wait)