1. An apparatus for performing binaural rendering for an input audio signal, the apparatus comprising:
a fast convolution unit configured to perform filtering each of a first group of subband signals of the input audio signal;
a tap-delay line processing unit configured to perform tap-delay line filtering each of a second group of subband signals
of the input audio signal,
wherein the fast convolution unit performs the filtering by using a plurality of sets of subband filter coefficients corresponding
to the first group of subband signals, respectively, and each set of subband filter coefficients has an independent length
determined according to a corresponding subband.