AUDIO SIGNAL DECODER, AUDIO SIGNAL ENCODER, METHOD OF DECODING AUDIO SIGNAL, METHOD OF ENCODING AUDIO SIGNAL AND COMPUTER PROGRAM USING PITCH-DEPENDENT ADAPTATION OF CODING CONTEXT Russian patent published in 2017 - IPC G10L21/04 G10L19/02 G10L19/22 

FIELD: acoustics.

SUBSTANCE: invention relates to means of encoding and decoding an audio signal. Audio signal decoder comprises a context-based spectral value decoder configured to decode a codeword, describing one or more spectral values or at least a portion of a number representation of one or more spectral values in dependence on a context state, to obtain decoded spectral values. Audio signal decoder also includes a context state determinator configured to determine a current context state in dependence on one or more previously decoded spectral values. Audio signal decoder also includes a time warping frequency-domain-to-time-domain converter configured to provide a time-warped time-domain representation of a given audio frame on basis of a set of decoded spectral values, associated with given audio frame and provided by context-based spectral value decoder.

EFFECT: technical result is improvement of efficiency of encoding in presence of oscillations of fundamental frequency.

18 cl, 51 dwg