適当な音声ファイルをffmpegでwavにしてsoxでspectrogramを作るやつ

spectrogram.rb

start = 0
sec = 2

if ARGV.length == 3
  file = ARGV[0]
  start = ARGV[1]
  sec = ARGV[2]
else
  file = ARGV[0]
end

filename = File.basename(file, '.*')

if !File.exist?(file)
  raise "File not exists"
end

wav_file = "#{filename}.wav"
system("ffmpeg -loglevel fatal -y -i #{file} -ac 1 #{wav_file}")

system("sox #{wav_file} -n trim #{start} #{sec} rate 12k spectrogram -y 300 -z 65 -o #{filename}.png")

puts "#{filename}.png successfully created"