chunkify_video.rb

#!/usr/bin/env ruby
#Convert a video into chunks of a given size

chunk = ARGV.shift.to_f
file = ARGV.shift
extension = File.extname(file)
basename = File.join(File.dirname(file), File.basename(file, extension))
durations = `ffmpeg -i '#{file}' 2>&1`.match(/Duration: ([\d:.]*)/).captures.first.split(':')
seconds = durations[0].to_f * 3600 + durations[1].to_f * 60 + durations[2].to_f
n_chunks = (seconds / chunk).ceil
(0...n_chunks).each { |chunk_number|
  filename = "#{basename} (Part #{chunk_number + 1} of #{n_chunks})#{extension}"
  puts `ffmpeg -i '#{file}' -ss #{chunk * chunk_number} -t #{chunk} '#{filename}'`
}