ENCODING AND DECODING AUDIO SIGNALS USING COMPLEX-VALUED FILTER BANK Russian patent published in 2010 - IPC G10L19/00 

FIELD: information technology.

SUBSTANCE: encoder has a receiver (201) which receives a time domain audio signal. A filter bank (203) generates a first subband signal from the time domain audio signal where the first subband signal corresponds to a non-critically sampled complex subband domain representation of the time domain signal. A conversion processor (205) generates a second subband signal from the first subband signal by subband processing. The second subband signal corresponds to a critically sampled complex subband domain representation of the time domain audio signals. An encode processor (207) then generates a waveform encoded data stream by encoding data values of the second subband signal. The conversion processor (205) generates the second subband signal by direct subband conversion without converting back to the time domain. The invention allows an oversampled subband signal usually generated in parametric encoding to be waveform encoded with reduced complexity. A decoder performs the inverse operation.

EFFECT: high accuracy of encoding audio signals.

28 cl, 11 dwg