A transmitter is disclosed for transmitting a digital information signal via a transmission medium. The digital information signal can be divided into one or more sub-signals. Each sub-signal is transmitted as a non-encoded or as an encoded signal. In which way the sub-signal is transmitted depends on the compression that can be achieved by the encoder. If the compression is low the sub-signal is transmitted in non-encoded form. For the receiver an identification is added to the composite signal to be transmitted. A first component of the identification signal indicates if one or more sub-signals are transmitted in encoded form. A second component of the identification signal indicates for each sub-signal whether it appears in encoded or non-encoded form in the composite signal. The invention provides a composite signal with a minimal number of bits.