mirror of https://github.com/python/cpython
167 lines
5.1 KiB
TeX
167 lines
5.1 KiB
TeX
% Documentations stolen and LaTeX'ed from comments in file.
|
|
\section{\module{wave} ---
|
|
Read and write WAV files}
|
|
|
|
\declaremodule{standard}{wave}
|
|
\sectionauthor{Moshe Zadka}{mzadka@geocities.com}
|
|
\modulesynopsis{Provide an interface to the WAV sound format.}
|
|
|
|
The \module{wave} module provides a convenient interface to the WAV sound
|
|
format. It does not support compression/decompression, but it does support
|
|
mono/stereo.
|
|
|
|
The \module{wave} module defines the following function and exception:
|
|
|
|
\begin{funcdesc}{open}{file, mode}
|
|
If \var{file} is a string, open the file by that name, other treat it
|
|
as a seekable file-like object. \var{mode} can be any of
|
|
\begin{description}
|
|
\item[\code{'r'}, \code{'rb'}] Read only mode.
|
|
\item[\code{'w'}, \code{'wb'}] Write only mode.
|
|
\end{description}
|
|
Note that it does not allow read/write WAV files.
|
|
|
|
A \var{mode} of \code{'r'} or \code{'rb'} returns a \class{Wave_read}
|
|
object, while a \var{mode} of \code{'w'} or \code{'wb'} returns
|
|
a \class{Wave_write} object.
|
|
\end{funcdesc}
|
|
|
|
\begin{funcdesc}{openfp}{file, mode}
|
|
A synonym for \function{open()}, maintained for backwards compatibility.
|
|
\end{funcdesc}
|
|
|
|
\begin{excdesc}{Error}
|
|
An error raised when something is impossible because it violates the
|
|
WAV specification or hits an implementation deficiency.
|
|
\end{excdesc}
|
|
|
|
|
|
\subsection{Wave_read Objects \label{Wave-read-objects}}
|
|
|
|
Wave_read objects, as returned by \function{open()}, have the
|
|
following methods:
|
|
|
|
\begin{methoddesc}[Wave_read]{close}{}
|
|
Close the stream, and make the instance unusable. This is
|
|
called automatically on object collection.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}[Wave_read]{getnchannels}{}
|
|
Returns number of audio channels (\code{1} for mono, \code{2} for
|
|
stereo).
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}[Wave_read]{getsampwidth}{}
|
|
Returns sample width in bytes.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}[Wave_read]{getframerate}{}
|
|
Returns sampling frequency.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}[Wave_read]{getnframes}{}
|
|
Returns number of audio frames.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}[Wave_read]{getcomptype}{}
|
|
Returns compression type (\code{'NONE'} is the only supported type).
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}[Wave_read]{getcompname}{}
|
|
Human-readable version of \method{getcomptype()}.
|
|
Usually \code{'not compressed'} parallels \code{'NONE'}.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}[Wave_read]{getparams}{}
|
|
Returns a tuple
|
|
\code{(\var{nchannels}, \var{sampwidth}, \var{framerate},
|
|
\var{nframes}, \var{comptype}, \var{compname})}, equivalent to output
|
|
of the \method{get*()} methods.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}[Wave_read]{readframes}{n}
|
|
Reads and returns at most \var{n} frames of audio, as a string of bytes.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}[Wave_read]{rewind}{}
|
|
Rewind the file pointer to the beginning of the audio stream.
|
|
\end{methoddesc}
|
|
|
|
The following two methods are defined for compatibility with the
|
|
\refmodule{aifc} module, and don't do anything interesting.
|
|
|
|
\begin{methoddesc}[Wave_read]{getmarkers}{}
|
|
Returns \code{None}.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}[Wave_read]{getmark}{id}
|
|
Raise an error.
|
|
\end{methoddesc}
|
|
|
|
The following two methods define a term ``position'' which is compatible
|
|
between them, and is otherwise implementation dependant.
|
|
|
|
\begin{methoddesc}[Wave_read]{setpos}{pos}
|
|
Set the file pointer to the specified position.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}[Wave_read]{tell}{}
|
|
Return current file pointer position.
|
|
\end{methoddesc}
|
|
|
|
|
|
\subsection{Wave_write Objects \label{Wave-write-objects}}
|
|
|
|
Wave_write objects, as returned by \function{open()}, have the
|
|
following methods:
|
|
|
|
\begin{methoddesc}[Wave_write]{close}{}
|
|
Make sure \var{nframes} is correct, and close the file.
|
|
This method is called upon deletion.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}[Wave_write]{setnchannels}{n}
|
|
Set the number of channels.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}[Wave_write]{setsampwidth}{n}
|
|
Set the sample width to \var{n} bytes.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}[Wave_write]{setframerate}{n}
|
|
Set the frame rate to \var{n}.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}[Wave_write]{setnframes}{n}
|
|
Set the number of frames to \var{n}. This will be changed later if
|
|
more frames are written.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}[Wave_write]{setcomptype}{type, name}
|
|
Set the compression type and description.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}[Wave_write]{setparams}{tuple}
|
|
The \var{tuple} should be \code{(\var{nchannels}, \var{sampwidth},
|
|
\var{framerate}, \var{nframes}, \var{comptype}, \var{compname})}, with
|
|
values valid for the \method{set*()} methods. Sets all parameters.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}[Wave_write]{tell}{}
|
|
Return current position in the file, with the same disclaimer for
|
|
the \method{Wave_read.tell()} and \method{Wave_read.setpos()}
|
|
methods.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}[Wave_write]{writeframesraw}{data}
|
|
Write audio frames, without correcting \var{nframes}.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}[Wave_write]{writeframes}{data}
|
|
Write audio frames and make sure \var{nframes} is correct.
|
|
\end{methoddesc}
|
|
|
|
Note that it is invalid to set any parameters after calling
|
|
\method{writeframes()} or \method{writeframesraw()}, and any attempt
|
|
to do so will raise \exception{wave.Error}.
|