Lib/toaiff.py

   1 # Convert "arbitrary" sound files to AIFF files (Apple and SGI's audio format).
   2 # Input may be compressed.
   3 # Uncompressed file type may be AIFF, WAV, VOC, 8SVX, NeXT/Sun, and others.
   4 # An exception is raised if the file is not of a recognized type.
   5 # Returned filename is either the input filename or a temporary filename;
   6 # in the latter case the caller must ensure that it is removed.
   7 # Other temporary files used are removed by the function.
   8
   9 import os
  10 import tempfile
  11 import pipes
  12 import sndhdr
  13
  14 table = {}
  15
  16 t = pipes.Template()
  17 t.append('sox -t au - -t aiff -r 8000 -', '--')
  18 table['au'] = t
  19
  20 # XXX The following is actually sub-optimal.
  21 # XXX The HCOM sampling rate can be 22k, 22k/2, 22k/3 or 22k/4.
  22 # XXX We must force the output sampling rate else the SGI won't play
  23 # XXX files sampled at 5.5k or 7.333k; however this means that files
  24 # XXX sampled at 11k are unnecessarily expanded.
  25 # XXX Similar comments apply to some other file types.
  26 t = pipes.Template()
  27 t.append('sox -t hcom - -t aiff -r 22050 -', '--')
  28 table['hcom'] = t
  29
  30 t = pipes.Template()
  31 t.append('sox -t voc - -t aiff -r 11025 -', '--')
  32 table['voc'] = t
  33
  34 t = pipes.Template()
  35 t.append('sox -t wav - -t aiff -', '--')
  36 table['wav'] = t
  37
  38 t = pipes.Template()
  39 t.append('sox -t 8svx - -t aiff -r 16000 -', '--')
  40 table['8svx'] = t
  41
  42 t = pipes.Template()
  43 t.append('sox -t sndt - -t aiff -r 16000 -', '--')
  44 table['sndt'] = t
  45
  46 t = pipes.Template()
  47 t.append('sox -t sndr - -t aiff -r 16000 -', '--')
  48 table['sndr'] = t
  49
  50 uncompress = pipes.Template()
  51 uncompress.append('uncompress', '--')
  52
  53
  54 error = 'toaiff.error' # Exception
  55
  56 def toaiff(filename):
  57         temps = []
  58         ret = None
  59         try:
  60                 ret = _toaiff(filename, temps)
  61         finally:
  62                 for temp in temps[:]:
  63                         if temp <> ret:
  64                                 try:
  65                                         os.unlink(temp)
  66                                 except os.error:
  67                                         pass
  68                                 temps.remove(temp)
  69         return ret
  70
  71 def _toaiff(filename, temps):
  72         if filename[-2:] == '.Z':
  73                 fname = tempfile.mktemp()
  74                 temps.append(fname)
  75                 sts = uncompress.copy(filename, fname)
  76                 if sts:
  77                         raise error, filename + ': uncomress failed'
  78         else:
  79                 fname = filename
  80         try:
  81                 ftype = sndhdr.whathdr(fname)
  82                 if ftype:
  83                         ftype = ftype[0] # All we're interested in
  84         except IOError:
  85                 if type(msg) == type(()) and len(msg) == 2 and \
  86                         type(msg[0]) == type(0) and type(msg[1]) == type(''):
  87                         msg = msg[1]
  88                 if type(msg) <> type(''):
  89                         msg = `msg`
  90                 raise error, filename + ': ' + msg
  91         if ftype == 'aiff':
  92                 return fname
  93         if ftype == None or not table.has_key(ftype):
  94                 raise error, \
  95                         filename + ': unsupported audio file type ' + `ftype`
  96         temp = tempfile.mktemp()
  97         temps.append(temp)
  98         sts = table[ftype].copy(fname, temp)
  99         if sts:
 100                 raise error, filename + ': conversion to aiff failed'
 101         return temp