Audio object coding and decoding method based on frequency spectrum shifting

Abstract

The invention discloses an audio object coding and decoding method based on frequency spectrum shifting. A strategy including global and local shifting is proposed to reduce aliasing distortion. In the coding stage, time-frequency transformation is carried out firstly to obtain frequency spectrum information of a plurality of input signals; then, whether aliasing occurs in each sub-band or not is judged, and aliasing areas are sequenced according to aliasing degrees; after a time-frequency region needing to be shifted is determined, aliasing time-frequency points are shifted to a non-aliasing region, a global shifting strategy and a local shifting strategy are adopted for shifting, and the global shifting can greatly reduce shifting information needing to be recorded; and finally, the down-mixed signal and the side information are synthesized into a code stream. In the decoding stage, the time-frequency component is recovered to the original position according to the shifting information, and then decoding is carried out according to a spatial audio object coding (SAOC) framework. According to the method, a frequency spectrum shifting strategy is utilized, the aliasing time-frequency information is shifted to the non-aliasing area in the down-mixing process, aliasing distortion is reduced, and the quality of decoded audio is improved.

Description

technical field [0001] The invention belongs to the technical field of digital audio signal processing, and in particular relates to an audio object encoding and decoding method based on frequency spectrum shifting, which is applicable to simultaneously transmitted multi-audio object signals, and restores each audio object with good sound quality at the decoding end. Background technique [0002] Spatial audio technology, also known as 3D audio, has grown in popularity for its unparalleled immersive listening experience that cannot be matched by mono or stereo audio. Traditional spatial audio coding schemes are based on channels, but this method has certain limitations [Document 1] [Document 2]. First, it is difficult to be compatible with non-standard playback environments. When the number and placement of speakers does not meet standard placement requirements, the spatial perception of audio is distorted. Second, channel-based spatial audio is difficult to support intera...

AI Technical Summary

Problems solved by technology

Its improved method improves the listener's listening experience to a certain extent, but the listener can still perceive the problem of aliasing and distortion

Images