Derivation of multichannel signals from two or more basic signals

Abstract

Multichannel signals and, in particular, three-dimensional signals make great demands on volumes of data to be transmitted or to be stored that need to be reduced as efficiently as possible. In this case, general known apparatuses or methods for such data reduction are parametric methods that extract spatial information, for example using the Fast Fourier Transform (FFT) known from the prior art, and then transmit it as a constant data stream together with a mono or stereo signal. Such technology is known particularly with MPEG surround, which uses a mono or stereo signal for its transmission. According to the invention, direct extraction of multichannel signals using correlation comparison, which firstly provides its mathematically exact solution for time-invariant (steady-state) signals, and has a specific residual response in the case of time-variant (non-steady-state) signals, results in direct verification of a signal that forms the basis of all residuals and that is very simple to determine. This can be used in audio coding, for example, for efficiently reducing artifacts or colorations of the tone and other de-masking effects and results in efficient coding of signals of the highest order (such as NHK 22.2).

Description

Background technique [0001] Multi-channel signals and especially three-dimensional signals such as audio signals place high demands on the amount of data to be transmitted or stored, which should be reduced as effectively as possible. [0002] Known general means or methods for such data reduction are here parametric methods, e.g. extracting spatial information according to the Fast Fourier Transform (FFT) known from the prior art, and then as a persistent data stream, e.g. with The mono signal or the stereo signal together is transmitted as a downmix signal. This audio technology is known especially as MPEG Surround and is an adaptive filtering method from a mathematical point of view. [0003] A pseudo-stereo approach is inverse coding (solution of the inverse problem in the case of spatial audio signals), which calculates signal components between left and right channels or side signals in monophonic signals and Allocation between main signals. For example, the angle bet...

AI Technical Summary

Problems solved by technology

In this case it is desirable to be able to universally determine these residuals in the encoder so that not all residuals have to be transmitted, which leads to significant bandwidth savings e.g. in audio coding

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