SYSTEM AND METHOD FOR REDUCING LATENCY IN TRANSPOSER-BASED VIRTUAL BASS SYSTEMS

摘要

A latency reduction system in a virtual bass processing system performs harmonic transposition on low frequency components of an audio signal to generate transposed data indicative of harmonics of the audio signal. The system uses a base transposition factor greater than two, and generates the harmonics in response to frequency-domain values determined by forward and inverse transform stages that use asymmetric analysis and synthesis windows. The system combines a virtual bass signal with the delayed wide band audio signal through analysis filter banks having filter coefficient truncated Nyquist filters. The virtual bass signal may lag the delayed wide band audio signal when combining with the audio signal to further reduce the latency caused by the harmonic transposition. The virtual bass input signal may be directly routed from a CQMF analysis filter bank of a preceding Hybrid filter bank stage, in order to avoid the delay associated with a Nyquist filter bank.

主权项

1. A method of generating low latency virtual bass, comprising:
receiving an input audio signal; performing harmonic transposition on low frequency components of the input audio signal to generate transposed data indicative of harmonics of the input audio signal; generating a virtual bass signal in response to the transposed data; and generating an enhanced audio signal by combining the virtual bass signal with a delayed version of the input audio signal, wherein the harmonic transposition employs combined transposition using a base transposition order B higher than 2 such that the harmonics include a second order harmonic and at least one higher order harmonic of each of the low frequency components, and such that all of the harmonics are generated in response to frequency-domain values determined by a common time-to-frequency domain transform stage using an asymmetric analysis window, and a subsequent inverse transform determined by a common frequency-to-time domain transform stage using an asymmetric synthesis window.