#!/usr/bin/ruby

require 'readline'
require 'fileutils'

o  = ARGV[0]
f = "/home/jgwong/tmp/disposable/runonce/temp-video-keyframes.mp4"
t  = "/home/jgwong/tmp/disposable/runonce/temp-video.mp4"

identify = "mplayer -vo null -ao null -frames 0 -identify "

ss     = 0
endpos = 1
run    = true

#print "Finding out FPS... "
#
#a = `ffmpeg -i #{o} 2>&1`
#
#if a =~ /, ([0-9\.]+?) fps/m
#  fps = $1
#  puts "#{fps}"
#else
#  puts "FAILED!"
#  exit
#end
#
#if ARGV[1] == 'no'
  FileUtils.cp o, f
#else
#  puts "Reencoding for keyframes, please wait patiently..."
#  STDOUT.flush
#  `mencoder #{o} -idx -nosound -fps #{fps} -ofps 24 -ovc x264 -x264encopts keyint=10:bitrate=10500 -o "#{f}" 2>&1`
#end

`mplayer -vo x11 #{f}`

while run
  endpos = ss + 1
  #`ffmpeg -ss #{ss} -t 1 -i "#{f}" -vcodec copy -an -y #{t}`
  `mencoder -ss #{ss} -endpos 1 -of lavf -lavfopts format=mp4 -ovc copy -nosound "#{f}" -o "#{t}" 2>&1`
  `mplayer -vo x11 #{t}`
  
  i = `#{identify} #{t}`
  
  i =~ /ID_LENGTH=(.+?)\n/m
  puts "Duration: #{$1}"
  
  a = Readline.readline("(#{ss}) =>", true)
  
  if a == 'q'
    ss -= 0.5
  elsif a == 'w'
    ss += 0.5
  elsif a == 'a'
    ss -= 0.1
  elsif a == 's'
    ss += 0.1
  elsif a == 'z'
    ss -= 0.01
  elsif a == 'x'
    ss += 0.01
  elsif a == 'all'
    `mplayer -vo x11 #{f}`
  elsif a == 'quit'
    run = false
  elsif a == 'save'
    FileUtils.cp t, o
    puts "Video saved. #{o}"
    puts
    run = false
  else
    ss = a.to_f
  end
  
  ss = 0 if ss < 0
end