Sync Subtitles

SyncSubs.md

Sync Subs

Synchronize .srt subtitles

Requirements

• Ruby

Usage

Usage: ruby syncsubs.rb [options]

• -i, --input NAME
  • SRT input file name
• -o, --output NAME
  • SRT output file name
• -s, --sync TIME
  • Sync time in milliseconds
• -h, --help
  • Prints this help

Examples:

ruby syncsubs.rb -i input.srt -o output.srt -s -500
ruby syncsubs.rb -i input.srt -o output.srt -s 1750

syncsubs.rb

#! /usr/bin/env ruby

# NAME          : Sync Subs
# DESCRIPTION   : Synchronize .srt subtitles
# AUTHOR        : Madh93 (Miguel Hernandez)
# VERSION       : 0.0.1
# LICENSE       : GNU General Public License v3
# USAGE         : ruby syncsubs.rb

require 'optparse'

Options = Struct.new(:input, :output, :sync)

# Extends String
class String
  def to_milli
    a = [1, 1000, 60_000, 3_600_000] * 2
    split(/[:\.]/).map { |time| time.to_i * a.pop }.inject(&:+)
  end
end

# Extends Fixnum
class Fixnum
  def to_time
    Time.at(to_f / 1000).utc.strftime('%H:%M:%S.%L')
  end
end

module SyncSubs
  # Argument Parser Class
  class ArgParser
    def self.parse(options)
      args = Options.new

      opt_parser = OptionParser.new do |opts|
        opts.banner = 'Usage: ruby syncsubs.rb [options]'

        opts.on('-i', '--input NAME', 'SRT input file name') do |f|
          args.input = f
        end

        opts.on('-o', '--output NAME', 'SRT output file name') do |f|
          args.output = f
        end

        opts.on('-s', '--sync TIME', 'Sync time in milliseconds') do |t|
          args.sync = t.to_i
        end

        opts.on('-h', '--help', 'Prints this help') do
          puts opts
          puts 'Example: ruby syncsubs.rb -i input.srt -o output.srt -s -500'
          exit
        end
      end

      opt_parser.parse!(options)
      if args.count(&:nil?) != 0
        puts 'Try: ruby syncsubs.rb --help'
        exit
      end
      args
    end
  end
end

module SyncSubs
  # Sync Subs class
  class SyncSubs
    attr_accessor :input, :output, :sync

    def initialize
      yield self if block_given?
    end

    def synchronize!
      # Read input subtitles
      begin
        data = File.readlines(@input)
      rescue
        puts "'#{@input}' can't be opened"
        exit
      end

      # Synchronize times
      data.map! { |line| line.include?('-->') ? sync_time(line) : line }

      # Export to output subtitles file
      File.open("#{@output}", 'w+') do |f|
        data.each { |line| f.write(line) }
      end
    end

    private

    def sync_time(str)
      # Split and remove commas
      str = str.tr(',', '.').split

      # Apply new sync time
      start = str[0].to_milli + @sync
      ending = str[2].to_milli + @sync

      if start < 0 || ending < 0
        puts "New sync time below 0... exiting."
        exit
      end

      "#{start.to_time} #{str[1]} #{ending.to_time}\n"
    end
  end
end

# Main
args = SyncSubs::ArgParser.parse(ARGV)

SyncSubs::SyncSubs.new do |s|
  s.input = args.input
  s.output = args.output
  s.sync = args.sync
end.synchronize!