.idx/.sub形式の字幕のオフセット時間をずらすスクリプト

idx_offset_change.rb

#!/usr/bin/env ruby

if ARGV.length != 4
  puts "#{$PROGRAM_NAME} in.idx out.idx secdiff ratio"
  puts "ex.) #{$PROGRAM_NAME} in.idx out.idx 15.34 1.01"
  exit(1)
end

in_path, out_path, time_diff, ratio = ARGV
time_diff = time_diff.to_f * 1000
ratio = ratio.to_f

timestamp_re = /\Atimestamp: (\d\d):(\d\d):(\d\d):(\d\d\d), filepos: ([A-Fa-f0-9]+)\z/

open(in_path, 'r') do |f|
  open(out_path, 'wb') do |of|
    f.each_line do |line|
      m = timestamp_re.match(line.chomp)
      if m
        hour, min, sec, msec, filepos = m[1..-1]
        t = ((hour.to_i * 60 + min.to_i) * 60 + sec.to_i) * 1000 + msec.to_i
        t += time_diff
        t *= ratio
        t = t.to_i

        m_msec = t % 1000
        m_sec = (t / 1000) % 60
        m_min = (t / 60000) % 60
        m_hour = (t / 3600000)

        o = sprintf("timestamp: %02d:%02d:%02d:%03d, filepos: %s\r\n", m_hour, m_min, m_sec, m_msec, filepos)

        of.puts(o)
      else
        of.puts(line)
      end
    end
  end
end