A ruby script to loop continuously through a folder structure to look for video files and downsize them using ffmpeg.

downsize_videos.rb

#!/usr/bin/env ruby

require "fileutils"

class Converter
  def initialize
    @queue = []
  end

  def push(path)
    if File.file?(path) && !@queue.include?(path)
      @queue.push(path)
    end
  end

  def queue
    @queue
  end

  # ref https://trac.ffmpeg.org/wiki/Encode/H.264 for more info on ffmpeg settings for mp4 vids
  def convert(input_path, output_path)
    FileUtils.mkdir_p File.dirname(output_path)
    pid = spawn("ffmpeg -y -i '#{input_path}' -vcodec libx264 -crf 24 -preset slower -strict -2 '#{output_path}'")
    Process.wait(pid)
  end
end

input_dir = "#{Dir.pwd}/input"
converter = Converter.new
tries = Hash.new {|h, k| h[k] = 0}
input_video_extensions = %w(MP4)

while (true)
  origin_path = Dir["../**/*.{#{input_video_extensions.join(',')}}"].shuffle.first
  if origin_path
    input_path = origin_path.gsub("..", "./input")
    output_path = input_path.gsub("input", "output").gsub(/(\.\w*)$/, ".mp4")
    FileUtils.mkdir_p File.dirname(input_path)
    FileUtils.cp origin_path, input_path

    status = converter.convert(input_path, output_path)
    if $?.exitstatus == 0
      FileUtils.rm input_path
      FileUtils.rm origin_path
      FileUtils.mv output_path, origin_path.gsub(/(\.\w*)$/, ".mp4")
    else
      # Well, if the exit status was en error, than for now just let the loop run
      # again and try to convert the file at some point.
    end
  else

   # No MP4 files, so wait a bit and try again - maybe new ones will appear.
   sleep 900
  end

  sleep 3
end