A communication system including a transmitter, a receiver, and a TMDS-like link, in which video data and auxiliary data (typically including timing data associated with other auxiliary data) are transmitted from the transmitter to the receiver, or in which video data are transmitted over the link from the transmitter to the receiver, and auxiliary data (typically including timing data associated with other auxiliary data) are transmitted from the receiver to the transmitter. In typical embodiments the auxiliary data include one or more streams of audio data. Other aspects are transmitters and receivers for use in such a system, methods for sending auxiliary data and video data over a TMDS-like link, methods for transmitting and recovering clocks for auxiliary data transmitted over such a link, methods for synchronizing auxiliary data transmitted over such a link with video data transmitted over such a link, and methods for generating clocks having frequency closely matching the rate at which the auxiliary data are transmitted over such a link.