code: def setup(self, bitdepth=16):
          
          fmt = self.get_file_format()
          newfmt = copy.copy(fmt)
  
          newfmt.mFormatID = AUDIO_ID_PCM
          newfmt.mFormatFlags = \
              PCM_IS_SIGNED_INT | PCM_IS_PACKED
          newfmt.mBitsPerChannel = bitdepth
          newfmt.mBytesPerPacket = \
              (fmt.mChannelsPerFrame * newfmt.mBitsPerChannel // 8)
          newfmt.mFramesPerPacket = 1
          newfmt.mBytesPerFrame = newfmt.mBytesPerPacket
          self.set_client_format(newfmt)
docs: Set the client format parameters, specifying the desired PCM
          audio data format to be read from the file. Must be called
          before reading from the file.