docs: def unpack_remb_fci(data):
      """
      Unpack the FCI for a Receiver Estimated Maximum Bitrate report.
  
      https://tools.ietf.org/html/draft-alvestrand-rmcat-remb-03
      """
      if len(data) < 8 or data[0:4] != b'REMB':
          raise ValueError('Invalid REMB prefix')
  
      exponent = (data[5] & 0xfc) >> 2
      mantissa = ((data[5] & 0x03) << 16) | (data[6] << 8) | data[7]
      bitrate = mantissa << exponent
  
      pos = 8
      ssrcs = []
      for r in range(data[4]):
          ssrcs.append(unpack_from('!L', data, pos)[0])
          pos += 4
  
      return (bitrate, ssrcs)