Patent ID: 7783493

Claim:
A method of decoding an audio signal performed by an audio coding system, comprising: receiving an audio signal including at least one frame, the frame comprising at least one time slot and at least one parameter set; extracting time slot information in variable bit length, the time slot information indicating a time slot to which a parameter set is applied; extracting parameter band information in fixed bit length, the parameter band information indicating a number of parameter bands for an entire frequency domain of the audio signal; and decoding the 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 the process of extracting time slot information, comprising: 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 of the first 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.