wave
— 读写 WAV 文件
¶
源代码： Lib/wave.py
wave
module provides a convenient interface to the WAV sound format. It does not support compression/decompression, but it does support mono/stereo.
wave
module defines the following function and exception:
wave.
open
(
file
,
mode=None
)
¶
若 file is a string, open the file by that name, otherwise treat it as a file-like object. mode can be:
'rb'
'wb'
Note that it does not allow read/write WAV files.
A
mode
of
'rb'
返回
Wave_read
object, while a
mode
of
'wb'
返回
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
close()
method is called; it is the caller’s responsibility to close the file object.
open()
function may be used in a
with
statement. When the
with
block completes, the
Wave_read.close()
or
Wave_write.close()
method is called.
3.4 版改变： Added support for unseekable files.
wave.
Error
¶
An error raised when something is impossible because it violates the WAV specification or hits an implementation deficiency.
Wave_read objects, as returned by
open()
, have the following methods:
Wave_read.
close
(
)
¶
Close the stream if it was opened by
wave
, and make the instance unusable. This is called automatically on object collection.
Wave_read.
getnchannels
(
)
¶
Returns number of audio channels (
1
for mono,
2
for stereo).
Wave_read.
getsampwidth
(
)
¶
Returns sample width in bytes.
Wave_read.
getframerate
(
)
¶
Returns sampling frequency.
Wave_read.
getnframes
(
)
¶
Returns number of audio frames.
Wave_read.
getcomptype
(
)
¶
Returns compression type (
'NONE'
is the only supported type).
Wave_read.
getcompname
(
)
¶
Human-readable version of
getcomptype()
. Usually
'not
compressed'
parallels
'NONE'
.
Wave_read.
getparams
(
)
¶
返回
namedtuple()
(nchannels,
sampwidth,
framerate,
nframes,
comptype,
compname)
, equivalent to output of the
get*()
方法。
Wave_read.
rewind
(
)
¶
Rewind the file pointer to the beginning of the audio stream.
The following two methods are defined for compatibility with the
aifc
module, and don’t do anything interesting.
Wave_read.
getmarkers
(
)
¶
返回
None
.
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.
Wave_read.
setpos
(
pos
)
¶
Set the file pointer to the specified position.
Wave_read.
tell
(
)
¶
Return current file pointer position.
For seekable output streams, the
wave
header will automatically be updated to reflect the number of frames actually written. For unseekable streams, the
nframes
value must be accurate when the first frame data is written. An accurate
nframes
value can be achieved either by calling
setnframes()
or
setparams()
with the number of frames that will be written before
close()
is called and then using
writeframesraw()
to write the frame data, or by calling
writeframes()
with all of the frame data to be written. In the latter case
writeframes()
will calculate the number of frames in the data and set
nframes
accordingly before writing the frame data.
Wave_write objects, as returned by
open()
, have the following methods:
3.4 版改变： Added support for unseekable files.
Wave_write.
close
(
)
¶
Make sure
nframes
is correct, and close the file if it was opened by
wave
. This method is called upon object collection. It will raise an exception if the output stream is not seekable and
nframes
does not match the number of frames actually written.
Wave_write.
setnchannels
(
n
)
¶
Set the number of channels.
Wave_write.
setsampwidth
(
n
)
¶
Set the sample width to n 字节。
Wave_write.
setframerate
(
n
)
¶
Set the frame rate to n .
3.2 版改变： A non-integral input to this method is rounded to the nearest integer.
Wave_write.
setnframes
(
n
)
¶
Set the number of frames to n . This will be changed later if the number of frames actually written is different (this update attempt will raise an error if the output stream is not seekable).
Wave_write.
setcomptype
(
type
,
name
)
¶
Set the compression type and description. At the moment, only compression type
NONE
is supported, meaning no compression.
Wave_write.
setparams
(
tuple
)
¶
tuple
应该为
(nchannels,
sampwidth,
framerate,
nframes,
comptype,
compname)
, with values valid for the
set*()
methods. Sets all parameters.
Wave_write.
tell
(
)
¶
Return current position in the file, with the same disclaimer for the
Wave_read.tell()
and
Wave_read.setpos()
方法。
Wave_write.
writeframesraw
(
data
)
¶
Write audio frames, without correcting nframes .
3.4 版改变： Any 像字节对象 现在被接受。
Wave_write.
writeframes
(
data
)
¶
Write audio frames and make sure nframes is correct. It will raise an error if the output stream is not seekable and the total number of frames that have been written after data has been written does not match the previously set value for nframes .
3.4 版改变： Any 像字节对象 现在被接受。
Note that it is invalid to set any parameters after calling
writeframes()
or
writeframesraw()
, and any attempt to do so will raise
wave.Error
.