#!/usr/bin/ruby

$stderr.puts "Usage #{__FILE__} out.raw"

if ARGV.size < 1 then
  exit
end

file_name = ARGV.shift
raw_data = nil
open(file_name){|io|
  io.binmode
  raw_data = io.read
}

marker_indexes = []
str_index = 0
while str_index
  str_index = raw_data.index(0xFF, str_index)
  if str_index then
    marker_indexes << str_index
    str_index += 1 
  end
end

marker_indexes.reject!{|str_index|
  packet_length = raw_data[str_index + 2, 2].unpack("n").first
  raw_data[str_index + 4 + packet_length] != 0xFF
}

marker_indexes.each{|str_index|
  marker_type = raw_data[str_index + 1]
  puts sprintf("%d => %02x", str_index, marker_type)
}