Download Twitch video that has muted sound.

ffmpeg.rb

#!/usr/bin/env ruby
files = Dir["*.ts"].sort_by { |fn| fn.split(".")[0].to_i }

puts "ffmpeg -i 'concat:#{files.join("|")}' -codec copy output.mkv"
puts
puts "run this first:"
puts "ulimit -n 4096"

wget.rb

#!/usr/bin/env ruby
# https://www.twitch.tv/videos/574519037
playlist_url = "http://dqrpb9wgowsf5.cloudfront.net/afe4f2fd56853c62507b_monstercat_37252580992_1397079807/chunked/index-muted-YE1NQ5PUXI.m3u8"
playlist_baseurl = playlist_url[0..playlist_url.rindex("/")]

File.read("index-muted-YE1NQ5PUXI.m3u8").split("\n").reject { |line| line.start_with?("#")  }.each do |line|
  url = if !line.start_with?("http://", "https://")
    "#{playlist_baseurl}#{line}"
  else
    line
  end

  if url.end_with?("-muted.ts")
    url = url[..-("-muted.ts".length+1)] + ".ts"
  end

  puts "wget #{url}"
end