Use icanhasaudio gem to decode mp3 and find the points of the sound wave to plot on a graph

mp3_visualizer.rb

#!/usr/local/bin/ruby
require 'stringio'
require 'rubygems'
require 'icanhasaudio'

reader = ::Audio::MPEG::Decoder.new
str_io = StringIO.new
input = File.open(ARGV[0], "rb")
plot_points = []
buf = reader.send(:skip_id3_header, input)
reader.send(:decode_headers_for, buf)
while !reader.mp3data.header_parsed?
  reader.send(:decode_headers_for, input.read(100))
end
reader.mp3data.nsamp = Audio::MPEG::Decoder::MP3Data::MAX_U_32_NUM unless reader.mp3data.total_frames > 0
reader.send(:native_decode, input, str_io)
str_leng = str_io.size - 1
str_leng.times do |i|
  str_io.seek(i)
  plot_points << str_io.read(4).unpack('ss') 
end