transcode.py

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