docs: def encode(self, fd, mtu, data):
          """
          Encode the supplied data (byte array) and write to
          the media transport file descriptor encapsulated
          as RTP packets.  The encoder will calculate the
          required number of SBC frames and encapsulate as
          RTP to fit the MTU size.
  
          :param int fd: Media transport file descriptor
          :param int mtu: Media transport MTU size as returned
              when the media transport was acquired.
          :param array{byte} data: Data to encode and send
              over the media transport.
          :return:
          """
          self.codec.rtp_sbc_encode_to_fd(self.config,
                                          ffi.new('char[]',
                                                  data),
                                          len(data),
                                          mtu,
                                          self.ts,
                                          self.seq_num,
                                          fd)