Upmixing method and system for multichannel audio reproduction

摘要

An audio signal enhancing device, and a corresponding method of enhancing stereophonic signals, is provided which generates an enhanced signal with improved spatial sound image quality for upmixing a stereophonic input signal. When used in combination with a centre channel processor or LFE processor, an improved processing of the input signals is provided resulting in final centre channel and at least one LFE sub-woofer channel wherein the problems and disadvantages of the prior art are resolved. The result is a centre and LFE signal that contains a stable, non time-smeared image with a high quality natural-sounding fidelity. These advantages are achieved especially for time-delayed or phase-panned stereo input signals, independently of whether they are matrix encoded or non-matrix encoded input signals.

主权项

1. An audio signal enhancing device for upmixing a stereophonic input signal comprising two audio signals, the device comprising:
signal enhancement means for processing the two input signals to generate at least one enhanced signal, the signal enhancement means comprising: two parallel processing lines comprising two parallel processing branches each; the first processing branch comprising adaptive filter means; and the second processing branch comprising means for delaying a signal; means for combining the output signal of the first processing branch of the first processing line with the output signal of the second processing branch of the second processing line to generate a first enhanced signal; means for combining the output signal of the first processing branch of the second processing line with the output signal of the second processing branch of the first processing line to generate a second enhanced signal; means for combining the first and second enhanced signals to generate a third enhanced signal; means for determining a dominant image direction of the third enhanced signal to determine a centre channel weighting coefficient that determines an output level of a centre channel to create a perception of sound location as in the direction of a single front side loudspeaker; and control means for controlling the signal enhancement means.