wave.py 文件源码

def _write_header(self, initlength):
        assert not self._headerwritten
        self._file.write('RIFF')
        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()
        self._file.write(struct.pack('<l4s4slhhllhh4s',
            36 + self._datalength, 'WAVE', 'fmt ', 16,
            WAVE_FORMAT_PCM, self._nchannels, self._framerate,
            self._nchannels * self._framerate * self._sampwidth,
            self._nchannels * self._sampwidth,
            self._sampwidth * 8, 'data'))
        self._data_length_pos = self._file.tell()
        self._file.write(struct.pack('<l', self._datalength))
        self._headerwritten = True