Over the past decades, a tremendous effort has been put into the research to develop advanced system for video communications over wireless and Internet channels. Because video communications are essentially delay-sensitive, bandwidth-intense and loss-tolerant, joint source-channel coding (JSCC) is investigated intensively to attain the optimum performance. The advances achieved in cross-layer design at the lower layers (PHY and DLL) can be further enhanced by taking into account source characteristics and requirements allowing existing networks to provide optimal time-varying Quality of...