Issue #1575020: Fixed support of 24-bit wave files on big-endian platforms.
diff --git a/Lib/wave.py b/Lib/wave.py
index d6eef78..c320238 100644
--- a/Lib/wave.py
+++ b/Lib/wave.py
@@ -82,15 +82,16 @@
_array_fmts = None, 'b', 'h', None, 'i'
-# Determine endian-ness
import struct
-if struct.pack("h", 1) == "\000\001":
- big_endian = 1
-else:
- big_endian = 0
-
+import sys
from chunk import Chunk
+def _byteswap3(data):
+ ba = bytearray(data)
+ ba[::3] = data[2::3]
+ ba[2::3] = data[::3]
+ return bytes(ba)
+
class Wave_read:
"""Variables used in this class:
@@ -231,7 +232,7 @@
self._data_seek_needed = 0
if nframes == 0:
return ''
- if self._sampwidth > 1 and big_endian:
+ 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
@@ -252,6 +253,8 @@
data = data.tostring()
else:
data = self._data_chunk.read(nframes * self._framesize)
+ if self._sampwidth == 3 and sys.byteorder == 'big':
+ data = _byteswap3(data)
if self._convert and data:
data = self._convert(data)
self._soundpos = self._soundpos + len(data) // (self._nchannels * self._sampwidth)
@@ -419,7 +422,7 @@
nframes = len(data) // (self._sampwidth * self._nchannels)
if self._convert:
data = self._convert(data)
- if self._sampwidth > 1 and big_endian:
+ if self._sampwidth in (2, 4) and sys.byteorder == 'big':
import array
data = array.array(_array_fmts[self._sampwidth], data)
assert data.itemsize == self._sampwidth
@@ -427,6 +430,8 @@
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)
self._nframeswritten = self._nframeswritten + nframes