cpython/Doc/library/sndhdr.rst

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:mod:`sndhdr` --- Determine type of sound file
==============================================
.. module:: sndhdr
:synopsis: Determine type of a sound file.
:deprecated:
.. sectionauthor:: Fred L. Drake, Jr. <fdrake@acm.org>
.. Based on comments in the module source file.
**Source code:** :source:`Lib/sndhdr.py`
.. index::
single: A-LAW
single: u-LAW
.. deprecated-removed:: 3.11 3.13
The :mod:`sndhdr` module is deprecated
(see :pep:`PEP 594 <594#sndhdr>` for details and alternatives).
--------------
The :mod:`sndhdr` provides utility functions which attempt to determine the type
of sound data which is in a file. When these functions are able to determine
what type of sound data is stored in a file, they return a
:func:`~collections.namedtuple`, containing five attributes: (``filetype``,
``framerate``, ``nchannels``, ``nframes``, ``sampwidth``). The value for *type*
indicates the data type and will be one of the strings ``'aifc'``, ``'aiff'``,
``'au'``, ``'hcom'``, ``'sndr'``, ``'sndt'``, ``'voc'``, ``'wav'``, ``'8svx'``,
``'sb'``, ``'ub'``, or ``'ul'``. The *sampling_rate* will be either the actual
value or ``0`` if unknown or difficult to decode. Similarly, *channels* will be
either the number of channels or ``0`` if it cannot be determined or if the
value is difficult to decode. The value for *frames* will be either the number
of frames or ``-1``. The last item in the tuple, *bits_per_sample*, will either
be the sample size in bits or ``'A'`` for A-LAW or ``'U'`` for u-LAW.
.. function:: what(filename)
Determines the type of sound data stored in the file *filename* using
:func:`whathdr`. If it succeeds, returns a namedtuple as described above, otherwise
``None`` is returned.
.. versionchanged:: 3.5
Result changed from a tuple to a namedtuple.
.. function:: whathdr(filename)
Determines the type of sound data stored in a file based on the file header.
The name of the file is given by *filename*. This function returns a namedtuple as
described above on success, or ``None``.
.. versionchanged:: 3.5
Result changed from a tuple to a namedtuple.
The following sound header types are recognized, as listed below with the return value
from :func:`whathdr`: and :func:`what`:
+------------+------------------------------------+
| Value | Sound header format |
+============+====================================+
| ``'aifc'`` | Compressed Audio Interchange Files |
+------------+------------------------------------+
| ``'aiff'`` | Audio Interchange Files |
+------------+------------------------------------+
| ``'au'`` | Au Files |
+------------+------------------------------------+
| ``'hcom'`` | HCOM Files |
+------------+------------------------------------+
| ``'sndt'`` | Sndtool Sound Files |
+------------+------------------------------------+
| ``'voc'`` | Creative Labs Audio Files |
+------------+------------------------------------+
| ``'wav'`` | Waveform Audio File Format Files |
+------------+------------------------------------+
| ``'8svx'`` | 8-Bit Sampled Voice Files |
+------------+------------------------------------+
| ``'sb'`` | Signed Byte Audio Data Files |
+------------+------------------------------------+
| ``'ub'`` | UB Files |
+------------+------------------------------------+
| ``'ul'`` | uLAW Audio Files |
+------------+------------------------------------+
.. data:: tests
A list of functions performing the individual tests. Each function takes two
arguments: the byte-stream and an open file-like object. When :func:`what` is
called with a byte-stream, the file-like object will be ``None``.
The test function should return a string describing the image type if the test
succeeded, or ``None`` if it failed.
Example:
.. code-block:: pycon
>>> import sndhdr
>>> imghdr.what('bass.wav')
'wav'
>>> imghdr.whathdr('bass.wav')
'wav'