AUDIO ENCODER, AUDIO DECODER, METHOD OF ENCODING AUDIO INFORMATION, METHOD OF DECODING AUDIO INFORMATION AND COMPUTER PROGRAM USING DETECTION OF GROUP OF PREVIOUSLY DECODED SPECTRAL VALUES

摘要

FIELD: acoustics.SUBSTANCE: invention relates to audio decoder, audio encoder, methods and computer-readable media for providing decoded and encoded audio information. Audio decoder comprises arithmetic decoder to provide plurality of decoded spectral values based on arithmetically encoded representation of spectral values and frequency-domain converter to time domain to provide time domain audio representation using decoded spectral values, where arithmetic decoder is configured to select mapping rule describing mapping of code value onto symbol code depending on state of context, also to determine current state of context depending on plurality of previously decoded spectral values and to detect set of previously decoded spectral values, which correspond to separately or together with preset magnitude relative to their values, as well as stating or change current state of context depending on result of detection.EFFECT: technical result consists in improvement of efficiency adjustment context.19 cl, 46 dwg