Up: MPEG Audio Compression Previous: Some facts - Use
convolution filters to divide the audio signal (e.g., 48 kHz
sound) into frequency subbands that approximate the 32 critical
bands -> sub-band - Determine amount of masking for each band
caused by nearby band using the results shown above (this is
called the psychoacoustic model). - If the power in a band is
below the masking threshold, don't encode it. - Otherwise,
determine number of bits needed to represent the coefficient
such that noise introduced by quantization is below the masking
effect (Recall that 1 bit of quantization introduces about 6 dB
of noise). - Format bitstream