Issue #19641: Added the audioop.byteswap() function to convert big-endian
samples to little-endian and vice versa.
diff --git a/Lib/wave.py b/Lib/wave.py
index 672d04b..b56395e 100644
--- a/Lib/wave.py
+++ b/Lib/wave.py
@@ -82,17 +82,12 @@
_array_fmts = None, 'b', 'h', None, 'i'
+import audioop
import struct
import sys
from chunk import Chunk
from collections import namedtuple
-def _byteswap3(data):
- ba = bytearray(data)
- ba[::3] = data[2::3]
- ba[2::3] = data[::3]
- return bytes(ba)
-
_wave_params = namedtuple('_wave_params',
'nchannels sampwidth framerate nframes comptype compname')
@@ -243,29 +238,9 @@
self._data_seek_needed = 0
if nframes == 0:
return b''
- if self._sampwidth in (2, 4) and sys.byteorder == 'big':
- # unfortunately the fromfile() method does not take
- # something that only looks like a file object, so
- # we have to reach into the innards of the chunk object
- import array
- chunk = self._data_chunk
- data = array.array(_array_fmts[self._sampwidth])
- assert data.itemsize == self._sampwidth
- nitems = nframes * self._nchannels
- if nitems * self._sampwidth > chunk.chunksize - chunk.size_read:
- nitems = (chunk.chunksize - chunk.size_read) // self._sampwidth
- data.fromfile(chunk.file.file, nitems)
- # "tell" data chunk how much was read
- chunk.size_read = chunk.size_read + nitems * self._sampwidth
- # do the same for the outermost chunk
- chunk = chunk.file
- chunk.size_read = chunk.size_read + nitems * self._sampwidth
- data.byteswap()
- data = data.tobytes()
- else:
- data = self._data_chunk.read(nframes * self._framesize)
- if self._sampwidth == 3 and sys.byteorder == 'big':
- data = _byteswap3(data)
+ data = self._data_chunk.read(nframes * self._framesize)
+ if self._sampwidth != 1 and sys.byteorder == 'big':
+ data = audioop.byteswap(data, self._sampwidth)
if self._convert and data:
data = self._convert(data)
self._soundpos = self._soundpos + len(data) // (self._nchannels * self._sampwidth)
@@ -441,20 +416,10 @@
nframes = len(data) // (self._sampwidth * self._nchannels)
if self._convert:
data = self._convert(data)
- if self._sampwidth in (2, 4) and sys.byteorder == 'big':
- import array
- a = array.array(_array_fmts[self._sampwidth])
- a.frombytes(data)
- data = a
- assert data.itemsize == self._sampwidth
- data.byteswap()
- data.tofile(self._file)
- self._datawritten = self._datawritten + len(data) * self._sampwidth
- else:
- if self._sampwidth == 3 and sys.byteorder == 'big':
- data = _byteswap3(data)
- self._file.write(data)
- self._datawritten = self._datawritten + len(data)
+ if self._sampwidth != 1 and sys.byteorder == 'big':
+ data = audioop.byteswap(data, self._sampwidth)
+ self._file.write(data)
+ self._datawritten += len(data)
self._nframeswritten = self._nframeswritten + nframes
def writeframes(self, data):