transcode.py

   1 import subprocess, shutil, os, re, sys
   2
   3 SCRIPTDIR = os.path.dirname(__file__)
   4 FFMPEG = os.path.join(SCRIPTDIR, 'ffmpeg_mp2.exe')
   5
   6 # XXX BIG HACK
   7 # subprocess is broken for me on windows so super hack
   8 def patchSubprocess():
   9     o = subprocess.Popen._make_inheritable
  10
  11     def _make_inheritable(self, handle):
  12         if not handle: return subprocess.GetCurrentProcess()
  13         return o(self, handle)
  14
  15     subprocess.Popen._make_inheritable = _make_inheritable
  16 mswindows = (sys.platform == "win32")
  17 if mswindows:
  18     patchSubprocess()
  19
  20 def output_video(inFile, outFile):
  21     if tivo_compatable(inFile):
  22         f = file(inFile, 'rb')
  23         shutil.copyfileobj(f, outFile)
  24         f.close()
  25     else:
  26         transcode(inFile, outFile)
  27
  28 def transcode(inFile, outFile):
  29
  30     cmd = [FFMPEG, '-i', inFile, '-vcodec', 'mpeg2video', '-r', '29.97', '-b', '4096'] + select_aspect(inFile)  +  ['-ac', '2', '-ab', '192', '-f', 'vob', '-' ]
  31     ffmpeg = subprocess.Popen(cmd, stdout=subprocess.PIPE)
  32     try:
  33         shutil.copyfileobj(ffmpeg.stdout, outFile)
  34     except:
  35         win32kill(ffmpeg.pid)
  36
  37 def select_aspect(inFile):
  38     type, height, width, fps =  video_info(inFile)
  39
  40     d = gcd(height,width)
  41
  42     rheight, rwidth = height/d, width/d
  43
  44     if (rheight, rwidth) in [(4, 3), (10, 11), (15, 11), (59, 54), (59, 72), (59, 36), (59, 54)]:
  45         return ['-aspect', '4:3', '-s', '720x480']
  46     elif (rheight, rwidth) in [(16, 9), (20, 11), (40, 33), (118, 81), (59, 27)]:
  47         return ['-aspect', '16:9', '-s', '720x480']
  48     else:
  49         settings = []
  50         settings.append('-aspect')
  51         settings.append('16:9')
  52
  53         endHeight = (720*width)/height
  54         if endHeight % 2:
  55             endHeight -= 1
  56
  57         settings.append('-s')
  58         settings.append('720x' + str(endHeight))
  59
  60         topPadding = ((480 - endHeight)/2)
  61         if topPadding % 2:
  62             topPadding -= 1
  63
  64         settings.append('-padtop')
  65         settings.append(str(topPadding))
  66         bottomPadding = (480 - endHeight) - topPadding
  67         settings.append('-padbottom')
  68         settings.append(str(bottomPadding))
  69
  70         return settings
  71
  72 def tivo_compatable(inFile):
  73     suportedModes = [[720, 480], [704, 480], [544, 480], [480, 480], [352, 480]]
  74     type, height, width, fps =  video_info(inFile)
  75
  76     if not type == 'mpeg2video':
  77         return False
  78
  79     if not fps == '29.97':
  80         return False
  81
  82     for mode in suportedModes:
  83         if (mode[0], mode[1]) == (height, width):
  84             return True
  85     return False
  86
  87 def video_info(inFile):
  88     cmd = [FFMPEG, '-i', inFile ]
  89     ffmpeg = subprocess.Popen(cmd, stderr=subprocess.PIPE, stdout=subprocess.PIPE, stdin=subprocess.PIPE)
  90     output = ffmpeg.stderr.read()
  91
  92     rezre = re.compile(r'.*Video: (.+), (\d+)x(\d+), (.+) fps.*')
  93     m = rezre.search(output)
  94     if m:
  95         return m.group(1), int(m.group(2)), int(m.group(3)), m.group(4)
  96     else:
  97         return None, None, None, None
  98
  99 def suported_format(inFile):
 100     if video_info(inFile)[0]:
 101         return True
 102     else:
 103         return False
 104
 105 def win32kill(pid):
 106         import ctypes
 107         handle = ctypes.windll.kernel32.OpenProcess(1, False, pid)
 108         ctypes.windll.kernel32.TerminateProcess(handle, -1)
 109         ctypes.windll.kernel32.CloseHandle(handle)
 110
 111 def gcd(a,b):
 112     while b:
 113         a, b = b, a % b
 114     return a