Patent ID: 8103513

Claim:
A broadcast playback system, comprising: a receiver configured to receive broadcast signal including an audio signal generated by downmixing a multi-channel audio signal; an application unit configured to store an audio codec for decoding an audio signal; a processor configured to perform operations of generating the multi-channel audio signal from the audio signal, the operations comprising: extracting time slot information in a variable bit length, the time slot information indicating a time slot to which a parameter set is applied; extracting parameter band information in a fixed bit length, the parameter band information indicating a number of parameter bands for an entire frequency domain of the audio signal; converting the audio signal into the multi-channel audio signal by applying a parameter of the parameter set to a parameter band of the time slot, based on the time slot information and the parameter band information, wherein extracting the time slot information comprises: extracting a number of time slots and a number of parameter sets from the audio signal to identify time slot information; determining a bit length of the time slot information, the bit length being variable according to the number of time slots and the number of parameter sets; and extracting the time slot information based on the bit length, wherein a number of the time slot information is equal to the number of parameter sets and the time slot information includes an absolute value indicating a time slot to which a first parameter set is applied or a difference value indicating a time slot to which a following parameter set is applied, wherein the absolute value is determined within a first maximum range, the first maximum range being calculated using the number of parameter sets and the number of time slots, and wherein the difference value is determined within a second maximum range, the second maximum range being calculated according to previous time slot information associated with a previous parameter set; a network interface configured to transmit the multi-channel audio signal or the audio signal to an external unit; an audio subsystem configured to convert the multi-channel audio signal into a multi-channel analog output signal; and a speaker configured to output at least one channel of the multi-channel analog output signal.