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 __all__ = ["error", "toaiff"]
  17
  18 table = {}
  19
  20 t = pipes.Template()
  21 t.append('sox -t au - -t aiff -r 8000 -', '--')
  22 table['au'] = t
  23
  24 # XXX The following is actually sub-optimal.
  25 # XXX The HCOM sampling rate can be 22k, 22k/2, 22k/3 or 22k/4.
  26 # XXX We must force the output sampling rate else the SGI won't play
  27 # XXX files sampled at 5.5k or 7.333k; however this means that files
  28 # XXX sampled at 11k are unnecessarily expanded.
  29 # XXX Similar comments apply to some other file types.
  30 t = pipes.Template()
  31 t.append('sox -t hcom - -t aiff -r 22050 -', '--')
  32 table['hcom'] = t
  33
  34 t = pipes.Template()
  35 t.append('sox -t voc - -t aiff -r 11025 -', '--')
  36 table['voc'] = t
  37
  38 t = pipes.Template()
  39 t.append('sox -t wav - -t aiff -', '--')
  40 table['wav'] = t
  41
  42 t = pipes.Template()
  43 t.append('sox -t 8svx - -t aiff -r 16000 -', '--')
  44 table['8svx'] = t
  45
  46 t = pipes.Template()
  47 t.append('sox -t sndt - -t aiff -r 16000 -', '--')
  48 table['sndt'] = t
  49
  50 t = pipes.Template()
  51 t.append('sox -t sndr - -t aiff -r 16000 -', '--')
  52 table['sndr'] = t
  53
  54 uncompress = pipes.Template()
  55 uncompress.append('uncompress', '--')
  56
  57
  58 class error(Exception):
  59     pass
  60
  61 def toaiff(filename):
  62     temps = []
  63     ret = None
  64     try:
  65         ret = _toaiff(filename, temps)
  66     finally:
  67         for temp in temps[:]:
  68             if temp != ret:
  69                 try:
  70                     os.unlink(temp)
  71                 except os.error:
  72                     pass
  73                 temps.remove(temp)
  74     return ret
  75
  76 def _toaiff(filename, temps):
  77     if filename[-2:] == '.Z':
  78         fname = tempfile.mktemp()
  79         temps.append(fname)
  80         sts = uncompress.copy(filename, fname)
  81         if sts:
  82             raise error, filename + ': uncompress failed'
  83     else:
  84         fname = filename
  85     try:
  86         ftype = sndhdr.whathdr(fname)
  87         if ftype:
  88             ftype = ftype[0] # All we're interested in
  89     except IOError, msg:
  90         if type(msg) == type(()) and len(msg) == 2 and \
  91                 type(msg[0]) == type(0) and type(msg[1]) == type(''):
  92             msg = msg[1]
  93         if type(msg) != type(''):
  94             msg = `msg`
  95         raise error, filename + ': ' + msg
  96     if ftype == 'aiff':
  97         return fname
  98     if ftype is None or not table.has_key(ftype):
  99         raise error, \
 100                 filename + ': unsupported audio file type ' + `ftype`
 101     temp = tempfile.mktemp()
 102     temps.append(temp)
 103     sts = table[ftype].copy(fname, temp)
 104     if sts:
 105         raise error, filename + ': conversion to aiff failed'
 106     return temp