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