The object of this part of IEC 1079 is to define the conditions and methods of measurement to be applied to MAC/packet decoder units. The specifications of the limit values of the various parameters of the decoder are outside the scope of this part . This unit can either be connected to the output of a DBS tuner unit or be a pa rt of it. The methods of measurement concerning the DBS tuner pa rt are described in part 2 of IEC 1079. The input signal is a baseband video signal encoded according to one of the following MAC standards: - D-MAC/packet; - D2 MAC/packet. The output signals are: - red, green, blue colour signals (R,G,B); - one or more audio signal(s); - the composite synchronization signal. NOTE - The methods of measurement can also be used for MAC/packet receivers with built-in MAC decoder units if R,G,B output signals are available.