diff options
Diffstat (limited to 'Lib/wave.py')
| -rw-r--r-- | Lib/wave.py | 88 |
1 files changed, 38 insertions, 50 deletions
diff --git a/Lib/wave.py b/Lib/wave.py index 4a223451bf..b56395ead7 100644 --- a/Lib/wave.py +++ b/Lib/wave.py @@ -18,7 +18,7 @@ This returns an instance of a class with the following public methods: getcomptype() -- returns compression type ('NONE' for linear samples) getcompname() -- returns human-readable version of compression type ('not compressed' linear samples) - getparams() -- returns a tuple consisting of all of the + getparams() -- returns a namedtuple consisting of all of the above in the above order getmarkers() -- returns None (for compatibility with the aifc module) @@ -82,15 +82,14 @@ WAVE_FORMAT_PCM = 0x0001 _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') class Wave_read: """Variables used in this class: @@ -169,6 +168,13 @@ class Wave_read: def __del__(self): self.close() + + def __enter__(self): + return self + + def __exit__(self, *args): + self.close() + # # User visible methods. # @@ -207,9 +213,9 @@ class Wave_read: return self._compname def getparams(self): - return self.getnchannels(), self.getsampwidth(), \ - self.getframerate(), self.getnframes(), \ - self.getcomptype(), self.getcompname() + return _wave_params(self.getnchannels(), self.getsampwidth(), + self.getframerate(), self.getnframes(), + self.getcomptype(), self.getcompname()) def getmarkers(self): return None @@ -232,29 +238,9 @@ class Wave_read: 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) @@ -328,6 +314,12 @@ class Wave_write: def __del__(self): self.close() + def __enter__(self): + return self + + def __exit__(self, *args): + self.close() + # # User visible methods. # @@ -402,8 +394,8 @@ class Wave_write: def getparams(self): if not self._nchannels or not self._sampwidth or not self._framerate: raise Error('not all parameters set') - return self._nchannels, self._sampwidth, self._framerate, \ - self._nframes, self._comptype, self._compname + return _wave_params(self._nchannels, self._sampwidth, self._framerate, + self._nframes, self._comptype, self._compname) def setmark(self, id, pos, name): raise Error('setmark() not supported') @@ -418,24 +410,16 @@ class Wave_write: return self._nframeswritten def writeframesraw(self, data): + if not isinstance(data, (bytes, bytearray)): + data = memoryview(data).cast('B') self._ensure_header_written(len(data)) 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): @@ -476,14 +460,18 @@ class Wave_write: if not self._nframes: self._nframes = initlength // (self._nchannels * self._sampwidth) self._datalength = self._nframes * self._nchannels * self._sampwidth - self._form_length_pos = self._file.tell() + try: + self._form_length_pos = self._file.tell() + except (AttributeError, OSError): + self._form_length_pos = None self._file.write(struct.pack('<L4s4sLHHLLHH4s', 36 + self._datalength, b'WAVE', b'fmt ', 16, WAVE_FORMAT_PCM, self._nchannels, self._framerate, self._nchannels * self._framerate * self._sampwidth, self._nchannels * self._sampwidth, self._sampwidth * 8, b'data')) - self._data_length_pos = self._file.tell() + if self._form_length_pos is not None: + self._data_length_pos = self._file.tell() self._file.write(struct.pack('<L', self._datalength)) self._headerwritten = True |