Spatial Audio Object Coding Based on Time-Frequency Shifting and Scheduling

Abstract

Spatial audio object coding (SAOC) is an effective method to transmit multiple audio objects. It divides the full frequency band into 28 subbands and extracts spatial parameters for de-coding. In this way, objects can be encoded into a downmix signal with a few parameters. However, using the same parameters in one subband will cause frequency aliasing distortion, which severely impacts the listening experience. Existing studies to enhance SAOC cannot eliminate the aliasing distortion of all objects effectively. This paper describes a new structure to balance the bit-rate and decode quality based on time-frequency (TF) shifting and scheduling. In this structure, a TF shifting strategy (contains global shifting and local shifting) is proposed to reduce frequency aliasing distortion. Furthermore, a scheduling strategy is used to decide which part should be shifted according to the degree of aliasing. From the experiment results, the performance of the proposed method is better than SAOC and other enhanced methods.