1. A method of decoding an audio signal, comprising: receiving an audio data frame having at least one channel, wherein the channel is subdivided into a plurality of blocks according to a subdivision hierarchy, the subdivision hierarchy has more than one level, and at least two of the plurality of blocks in the channel for each level are capable of different lengths; obtaining information from the audio signal indicating the subdivision of the channel into the plurality of blocks; obtaining an optimum prediction order for each block in the channel, a prediction order indicating a number of prediction coefficients; predicting current data samples in the channel based on the optimum prediction order; decoding the channel based on the obtained information and a residual of the current data samples, wherein the obtained information includes a number of information bits, each information bit is associated with a level in the subdivision hierarchy and is associated with a block at the associated level, each information bit indicates whether the associated block was subdivided, and the number of the information bits is decided based on a number of levels in the subdivision hierarchy, wherein the optimum prediction order indicates a minimum one of a global prediction order and a local prediction order, the global prediction order having been determined based on a maximum permitted prediction order, the local prediction order having been determined based on a length of the block.