transcode.py

   1 import subprocess, shutil, os, re, sys
   2
   3 SCRIPTDIR = os.path.dirname(__file__)
   4
   5 # XXX BIG HACK
   6 # subprocess is broken for me on windows so super hack
   7 def patchSubprocess():
   8     o = subprocess.Popen._make_inheritable
   9
  10     def _make_inheritable(self, handle):
  11         if not handle: return subprocess.GetCurrentProcess()
  12         return o(self, handle)
  13
  14     subprocess.Popen._make_inheritable = _make_inheritable
  15 mswindows = (sys.platform == "win32")
  16 if mswindows:
  17     patchSubprocess()
  18
  19 def output_video(inFile, outFile):
  20     if tivo_compatable(inFile):
  21         f = file(inFile, 'rb')
  22         shutil.copyfileobj(f, outFile)
  23         f.close()
  24     else:
  25         transcode(inFile, outFile)
  26
  27 def transcode(inFile, outFile):
  28
  29     cmd = SCRIPTDIR + "\\ffmpeg_mp2.exe -i \"%s\" -vcodec mpeg2video -r 29.97 -b 4096 %s -ac 2 -ab 192 -f vob -" % (inFile, select_aspect(inFile))
  30     # subprocess is busted in my python 2.5 when run without a console. Setting all to PIPE fixes it.
  31     # but now we get this nice select loop to dump the stderr data
  32     ffmpeg = subprocess.Popen(cmd, stdout=subprocess.PIPE)
  33     try:
  34         shutil.copyfileobj(ffmpeg.stdout, outFile)
  35     except:
  36         win32kill(ffmpeg.pid)
  37
  38 def select_aspect(inFile):
  39     type, height, width, fps =  video_info(inFile)
  40
  41     d = gcd(height,width)
  42
  43     rheight, rwidth = height/d, width/d
  44
  45     if (rheight, rwidth) in [(4, 3), (10, 11), (15, 11), (59, 54), (59, 72), (59, 36), (59, 54)]:
  46         return '-aspect 4:3 -s 720x480'
  47     elif (rheight, rwidth) in [(16, 9), (20, 11), (40, 33), (118, 81), (59, 27)]:
  48         return '-aspect 16:9 -s 720x480'
  49     else:
  50         settings = []
  51         settings.append('-aspect 16:9')
  52
  53         endHeight = (720*width)/height
  54         if endHeight % 2:
  55             endHeight -= 1
  56
  57         settings.append('-s 720x' + str(endHeight))
  58
  59         topPadding = ((480 - endHeight)/2)
  60         if topPadding % 2:
  61             topPadding -= 1
  62
  63         settings.append('-padtop ' + str(topPadding))
  64         bottomPadding = (480 - endHeight) - topPadding
  65         settings.append('-padbottom ' + str(bottomPadding))
  66
  67         return ' '.join(settings)
  68
  69 def tivo_compatable(inFile):
  70     suportedModes = [[720, 480], [704, 480], [544, 480], [480, 480], [352, 480]]
  71     type, height, width, fps =  video_info(inFile)
  72
  73     if not type == 'mpeg2video':
  74         return False
  75
  76     if not fps == '29.97':
  77         return False
  78
  79     for mode in suportedModes:
  80         if (mode[0], mode[1]) == (height, width):
  81             return True
  82     return False
  83
  84 def video_info(inFile):
  85     cmd = SCRIPTDIR + "\\ffmpeg_mp2.exe -i \"%s\"" % inFile
  86     ffmpeg = subprocess.Popen(cmd, stderr=subprocess.PIPE, stdout=subprocess.PIPE, stdin=subprocess.PIPE)
  87     output = ffmpeg.stderr.read()
  88
  89     rezre = re.compile(r'.*Video: (.+), (\d+)x(\d+), (.+) fps.*')
  90     m = rezre.search(output)
  91     if m:
  92         return m.group(1), int(m.group(2)), int(m.group(3)), m.group(4)
  93     else:
  94         return None, None, None, None
  95
  96 def suported_format(inFile):
  97     if video_info(inFile)[0]:
  98         return True
  99     else:
 100         return False
 101
 102 def win32kill(pid):
 103         import ctypes
 104         handle = ctypes.windll.kernel32.OpenProcess(1, False, pid)
 105         ctypes.windll.kernel32.TerminateProcess(handle, -1)
 106         ctypes.windll.kernel32.CloseHandle(handle)
 107
 108 def gcd(a,b):
 109     while b:
 110         a, b = b, a % b
 111     return a