Patent ID: 8706507

Claim:
A digital audio transform encoding method employing transform blocks for encoding a discrete time-domain signal, the method employing quantization of a frequency-domain representation of the discrete time-domain signal, comprising deriving ( 20 , 22 ), in the frequency domain, a measure of frequency-domain quantization error (E(k)), filtering ( 24 ), in the frequency domain, the measure of quantization error to produce a filtered measure of quantization error, and applying ( 26 ), in the frequency domain, the filtered measure of quantization error as a feedback signal to the frequency-domain representation of the discrete time-domain signal prior to frequency-domain quantization ( 20 ), whereby the filtering parameters of said filtering affect the temporal shaping of quantization noise within a transform block and with unchanged quantization so as to have an arbitrary shape in the time domain resolution when the quantized frequency-domain representation of the discrete time-domain signal is inversely transformed from the frequency domain back to the time domain.