docs: def decode(self, fd, mtu, max_len=2560):
          """
          Read the media transport descriptor, depay
          the RTP payload and decode the SBC frames into
          a byte array.  The maximum number of bytes to
          be returned may be passed as an argument and all
          available bytes are returned to the caller.
  
          :param int fd: Media transport file descriptor
          :param int mtu: Media transport MTU size as returned
              when the media transport was acquired.
          :param int max_len: Optional.  Set maximum number of
              bytes to read.
          :return data: Decoded data bytes as an array.
          :rtype: array{byte}
          """
          output_buffer = ffi.new('char[]', max_len)
          sz = self.codec.rtp_sbc_decode_from_fd(self.config,
                                                 output_buffer,
                                                 max_len,
                                                 mtu,
                                                 fd)
          return ffi.buffer(output_buffer[0:sz])