##
14.4.1 AU_read Objects

AU_read objects, as returned by `open()` above, have the following methods:

`close` ()
  Close the stream, and make the instance unusable. (This is called automatically on deletion.)

`getnchannels` ()
  Returns number of audio channels (1 for mone, 2 for stereo).

`getsampwidth` ()
  Returns sample width in bytes.

`getframerate` ()
  Returns sampling frequency.

`getnframes` ()
  Returns number of audio frames.

`getcomptype` ()
  Returns compression type. Supported compression types are `'ULAW'`, `'ALAW'` and `'NONE'`.

`getcompname` ()
  Human-readable version of `getcomptype()`. The supported types have the respective names `'CCITT G.711 u-law'`, `'CCITT G.711 A-law'` and `'not compressed'`.

`getparams` ()
  Returns a tuple `(nchannels, sampwidth, framerate, nframes, comptype, compname)`, equivalent to output of the `get*()` methods.

`readframes` (n)
  Reads and returns at most n frames of audio, as a string of bytes.

`rewind` ()
  Rewind the file pointer to the beginning of the audio stream.

The following two methods define a term ``position'' which is compatible between them, and is otherwise implementation dependant.

`setpos` (pos)
  Set the file pointer to the specified position.

`tell` ()
  Return current file pointer position.

The following two functions are defined for compatibility with the `aifc`, and don't do anything interesting.

`getmarkers` ()
  Returns `None`.

`getmark` (id)
  Raise an error.