media_duration.rb

#! /usr/bin/env ruby

=begin

Determines total duration of all media files, passed as arguments.

Shells out to ffmpeg(1).

=end

require 'open3'
require 'shellwords'

def len(media_file)
  _, stderr_str, _ = Open3.capture3("ffmpeg -i #{media_file.shellescape}")

  /^\s*Duration: (?<hours>\d+):(?<minutes>\d+):(?<seconds>[\d\.]+), / =~ stderr_str

  stats = Hash.new(0)

  stats[:hours] = hours.to_i
  stats[:minutes] = minutes.to_i
  stats[:seconds] = seconds.to_f

  stats
end

if __FILE__ == $PROGRAM_NAME
  weeks, days, hours, minutes, seconds = 0, 0, 0, 0, 0

  if ARGV.empty?
    puts "Usage:\t#{File.basename($PROGRAM_NAME)} FILENAME..."
    exit 0
  end

  ARGV.each do |f|
    stats = len(f)
    hours += stats[:hours]
    minutes += stats[:minutes]
    seconds += stats[:seconds]
  end

  seconds = seconds.round

  if seconds >= 60
    minutes += seconds / 60
    seconds = seconds % 60
  end

  if minutes >= 60
    hours += minutes / 60
    minutes = minutes % 60
  end

  days, hours = hours.divmod(24) if hours >= 24
  weeks, days = days.divmod(7) if days >= 7

  message = "Total duration: "

  message << "#{weeks} weeks, "     unless weeks.zero?
  message << "#{days} days, "       unless days.zero?
  message << "#{hours} hours, "     unless hours.zero?
  message << "#{minutes} minutes, " unless minutes.zero?
  message << "#{seconds} seconds."

  puts message
end