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         (fd, fname) = tempfile.mkstemp()

    79         os.close(fd)

    80         temps.append(fname)

    81         sts = uncompress.copy(filename, fname)

    82         if sts:

    83             raise error, filename + ': uncompress failed'

    84     else:

    85         fname = filename

    86     try:

    87         ftype = sndhdr.whathdr(fname)

    88         if ftype:

    89             ftype = ftype[0] # All we're interested in

    90     except IOError, msg:

    91         if type(msg) == type(()) and len(msg) == 2 and \

    92                 type(msg[0]) == type(0) and type(msg[1]) == type(''):

    93             msg = msg[1]

    94         if type(msg) != type(''):

    95             msg = repr(msg)

    96         raise error, filename + ': ' + msg

    97     if ftype == 'aiff':

    98         return fname

    99     if ftype is None or not ftype in table:

   100         raise error, '%s: unsupported audio file type %r' % (filename, ftype)

   101     (fd, temp) = tempfile.mkstemp()

   102     os.close(fd)

   103     temps.append(temp)

   104     sts = table[ftype].copy(fname, temp)

   105     if sts:

   106         raise error, filename + ': conversion to aiff failed'

   107     return temp