mirror of
https://github.com/python/cpython.git
synced 2024-12-01 03:01:36 +01:00
536ffe161c
'mode' docs fix: the file must always be opened in binary in Python3. Bug in Wave_write.close: when the close method calls the check that the header exists and it raises an error, the _file attribute never gets set to None, so the next close tries to close the file again and we get an ignored traceback in the __del__ method. The fix is to set _file to None in a finally clause. This represents a behavior change...in theory a program could be checking for the error on close and then doing a recovery action on the still open file and closing it again. But this change will only go into 3.4, so I think that behavior change is acceptable given that it would be pretty weird and unlikely logic to begin with.
218 lines
5.2 KiB
ReStructuredText
218 lines
5.2 KiB
ReStructuredText
:mod:`wave` --- Read and write WAV files
|
|
========================================
|
|
|
|
.. module:: wave
|
|
:synopsis: Provide an interface to the WAV sound format.
|
|
.. sectionauthor:: Moshe Zadka <moshez@zadka.site.co.il>
|
|
.. Documentations stolen from comments in file.
|
|
|
|
**Source code:** :source:`Lib/wave.py`
|
|
|
|
--------------
|
|
|
|
The :mod:`wave` module provides a convenient interface to the WAV sound format.
|
|
It does not support compression/decompression, but it does support mono/stereo.
|
|
|
|
The :mod:`wave` module defines the following function and exception:
|
|
|
|
|
|
.. function:: open(file, mode=None)
|
|
|
|
If *file* is a string, open the file by that name, otherwise treat it as a
|
|
seekable file-like object. *mode* can be:
|
|
|
|
``'rb'``
|
|
Read only mode.
|
|
|
|
``'wb'``
|
|
Write only mode.
|
|
|
|
Note that it does not allow read/write WAV files.
|
|
|
|
A *mode* of ``'rb'`` returns a :class:`Wave_read` object, while a *mode* of
|
|
``'wb'`` returns a :class:`Wave_write` object. If *mode* is omitted and a
|
|
file-like object is passed as *file*, ``file.mode`` is used as the default
|
|
value for *mode*.
|
|
|
|
If you pass in a file-like object, the wave object will not close it when its
|
|
:meth:`close` method is called; it is the caller's responsibility to close
|
|
the file object.
|
|
|
|
The :func:`.open` function may be used in a :keyword:`with` statement. When
|
|
the :keyword:`with` block completes, the :meth:`Wave_read.close()
|
|
<wave.Wave_read.close>` or :meth:`Wave_write.close()
|
|
<wave.Wave_write.close()>` method is called.
|
|
|
|
|
|
.. function:: openfp(file, mode)
|
|
|
|
A synonym for :func:`.open`, maintained for backwards compatibility.
|
|
|
|
|
|
.. exception:: Error
|
|
|
|
An error raised when something is impossible because it violates the WAV
|
|
specification or hits an implementation deficiency.
|
|
|
|
|
|
.. _wave-read-objects:
|
|
|
|
Wave_read Objects
|
|
-----------------
|
|
|
|
Wave_read objects, as returned by :func:`.open`, have the following methods:
|
|
|
|
|
|
.. method:: Wave_read.close()
|
|
|
|
Close the stream if it was opened by :mod:`wave`, and make the instance
|
|
unusable. This is called automatically on object collection.
|
|
|
|
|
|
.. method:: Wave_read.getnchannels()
|
|
|
|
Returns number of audio channels (``1`` for mono, ``2`` for stereo).
|
|
|
|
|
|
.. method:: Wave_read.getsampwidth()
|
|
|
|
Returns sample width in bytes.
|
|
|
|
|
|
.. method:: Wave_read.getframerate()
|
|
|
|
Returns sampling frequency.
|
|
|
|
|
|
.. method:: Wave_read.getnframes()
|
|
|
|
Returns number of audio frames.
|
|
|
|
|
|
.. method:: Wave_read.getcomptype()
|
|
|
|
Returns compression type (``'NONE'`` is the only supported type).
|
|
|
|
|
|
.. method:: Wave_read.getcompname()
|
|
|
|
Human-readable version of :meth:`getcomptype`. Usually ``'not compressed'``
|
|
parallels ``'NONE'``.
|
|
|
|
|
|
.. method:: Wave_read.getparams()
|
|
|
|
Returns a :func:`~collections.namedtuple` ``(nchannels, sampwidth,
|
|
framerate, nframes, comptype, compname)``, equivalent to output of the
|
|
:meth:`get\*` methods.
|
|
|
|
|
|
.. method:: Wave_read.readframes(n)
|
|
|
|
Reads and returns at most *n* frames of audio, as a string of bytes.
|
|
|
|
|
|
.. method:: Wave_read.rewind()
|
|
|
|
Rewind the file pointer to the beginning of the audio stream.
|
|
|
|
The following two methods are defined for compatibility with the :mod:`aifc`
|
|
module, and don't do anything interesting.
|
|
|
|
|
|
.. method:: Wave_read.getmarkers()
|
|
|
|
Returns ``None``.
|
|
|
|
|
|
.. method:: Wave_read.getmark(id)
|
|
|
|
Raise an error.
|
|
|
|
The following two methods define a term "position" which is compatible between
|
|
them, and is otherwise implementation dependent.
|
|
|
|
|
|
.. method:: Wave_read.setpos(pos)
|
|
|
|
Set the file pointer to the specified position.
|
|
|
|
|
|
.. method:: Wave_read.tell()
|
|
|
|
Return current file pointer position.
|
|
|
|
|
|
.. _wave-write-objects:
|
|
|
|
Wave_write Objects
|
|
------------------
|
|
|
|
Wave_write objects, as returned by :func:`.open`, have the following methods:
|
|
|
|
|
|
.. method:: Wave_write.close()
|
|
|
|
Make sure *nframes* is correct, and close the file if it was opened by
|
|
:mod:`wave`. This method is called upon object collection.
|
|
|
|
|
|
.. method:: Wave_write.setnchannels(n)
|
|
|
|
Set the number of channels.
|
|
|
|
|
|
.. method:: Wave_write.setsampwidth(n)
|
|
|
|
Set the sample width to *n* bytes.
|
|
|
|
|
|
.. method:: Wave_write.setframerate(n)
|
|
|
|
Set the frame rate to *n*.
|
|
|
|
.. versionchanged:: 3.2
|
|
A non-integral input to this method is rounded to the nearest
|
|
integer.
|
|
|
|
|
|
.. method:: Wave_write.setnframes(n)
|
|
|
|
Set the number of frames to *n*. This will be changed later if more frames are
|
|
written.
|
|
|
|
|
|
.. method:: Wave_write.setcomptype(type, name)
|
|
|
|
Set the compression type and description. At the moment, only compression type
|
|
``NONE`` is supported, meaning no compression.
|
|
|
|
|
|
.. method:: Wave_write.setparams(tuple)
|
|
|
|
The *tuple* should be ``(nchannels, sampwidth, framerate, nframes, comptype,
|
|
compname)``, with values valid for the :meth:`set\*` methods. Sets all
|
|
parameters.
|
|
|
|
|
|
.. method:: Wave_write.tell()
|
|
|
|
Return current position in the file, with the same disclaimer for the
|
|
:meth:`Wave_read.tell` and :meth:`Wave_read.setpos` methods.
|
|
|
|
|
|
.. method:: Wave_write.writeframesraw(data)
|
|
|
|
Write audio frames, without correcting *nframes*.
|
|
|
|
|
|
.. method:: Wave_write.writeframes(data)
|
|
|
|
Write audio frames and make sure *nframes* is correct.
|
|
|
|
|
|
Note that it is invalid to set any parameters after calling :meth:`writeframes`
|
|
or :meth:`writeframesraw`, and any attempt to do so will raise
|
|
:exc:`wave.Error`.
|
|
|