Lib/toaiff.py

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