text: # Author: Anthony Baxter
  
  """Class representing audio/* type MIME documents.
  """
  
  import sndhdr
  from cStringIO import StringIO
  
  import MIMEBase
  import Errors
  import Encoders
  
  
  
  _sndhdr_MIMEmap = {'au'  : 'basic',
                     'wav' :'x-wav',
                     'aiff':'x-aiff',
                     'aifc':'x-aiff',
                     }
  
  # There are others in sndhdr that don't have MIME types. :(
  # Additional ones to be added to sndhdr? midi, mp3, realaudio, wma??
  def _whatsnd(data):
      """Try to identify a sound file type.
  
      sndhdr.what() has a pretty cruddy interface, unfortunately.  This is why
      we re-do it here.  It would be easier to reverse engineer the Unix 'file'
      command and use the standard 'magic' file, as shipped with a modern Unix.
      """
      hdr = data[:512]
      fakefile = StringIO(hdr)
      for testfn in sndhdr.tests:
          res = testfn(hdr, fakefile)
          if res is not None:
              return _sndhdr_MIMEmap.get(res[0])
      return None
  
  
  
  class MIMEAudio(MIMEBase.MIMEBase):
      """Class for generating audio/* MIME documents."""
  
      def __init__(self, _audiodata, _subtype=None,
                   _encoder=Encoders.encode_base64, **_params):
          """Create an audio/* type MIME document.
  
          _audiodata is a string containing the raw audio data.  If this data
          can be decoded by the standard Python `sndhdr' module, then the
          subtype will be automatically included in the Content-Type: header.
          Otherwise, you can specify  the specific audio subtype via the
          _subtype parameter.  If _subtype is not given, and no subtype can be
          guessed, a TypeError is raised.
  
          _encoder is a function which will perform the actual encoding for
          transport of the image data.  It takes one argument, which is this
          Image instance.  It should use get_payload() and set_payload() to
          change the payload to the encoded form.  It should also add any
          Content-Transfer-Encoding: or other headers to the message as
          necessary.  The default encoding is Base64.
  
          Any additional keyword arguments are passed to the base class
          constructor, which turns them into parameters on the Content-Type:
          header.
          """
          if _subtype is None:
              _subtype = _whatsnd(_audiodata)
          if _subtype is None:
              raise TypeError, 'Could not find audio MIME subtype'
          MIMEBase.MIMEBase.__init__(self, 'audio', _subtype, **_params)
          self.set_payload(_audiodata)
          _encoder(self)
  