##
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 dependent.

`setpos` (pos)
  Set the file pointer to the specified position. Only values returned from `tell()` should be used for pos.

`tell` ()
  Return current file pointer position. Note that the returned value has nothing to do with the actual position in the file.

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.