Koninklijke Philips Corporation N.v.

Roy Irwan

Ronaldus Maria Aarts

Daniel Willem Elisabeth Schobben

Erik Larsen

In a method and a media system of/for generation of at least one output signal (H,H) from at least one input signal belonging to a second set of sound signals (M) having a related second set of Head Related Transfer Functions, in which the media system can be a TV, a CD player, a DVD player, a Radio, a display, an amplifier, a headphone or a VCR, the method includes the steps of determining, for each signal in the second set of sound signals, a weighted relation () including at least one signal belonging to a third set of intermediate sound signals (CHI, CHI) and at least one weight value (Weights); determining a first set of Head Related Transfer Functions (HRTFs) based on the second set of sound signals, the second set of Head Related Transfer Functions and the weighted relation; and transferring at least one signal belonging to the third set of intermediate sound signals by means of at least one HRTF belonging to said first set of Head Related Transfer Functions in order to generate at least one output signal belonging to said first set of sound signals. Hereby, in the end, fewer HRTFs are determined for a subsequent transfer of input signal(s) to output signal(s). Accordingly, few convolutions are required.

Generation of a sound signal

A method of encoding a multichannel signal, such as a stereophonic audio signal, including at least first and second signal components includes transforming at least the first and second signal components by a predetermined transformation into a principal signal including most of the signal energy and at least one residual signal including less energy than the principal signal. The predetermined transformation is parameterized by at least one transformation parameter. The method further includes representing the multichannel signal at least by the principal signal and the transformation parameter.

Coding of stereo signals

A method of encoding a multi-channel signal having first and second signal components includes determining a set of filter parameters a prediction filter such that the prediction filter provides an estimate of the second signal component when receiving the first signal component as an input. The multi-channel signal is represented as the first signal component and the set of filter parameters. A corresponding decoding method and arrangements for encoding and decoding multi-channel signals are also provided.

An audio reproducing device includes an input for receiving an n-channel input signal, an output for supplying an 1-channel output signal to 1 loudspeakers, and an audio processing unit for processing the input signal. The audio processing unit a signal enhancer for enhancing an m-channel signal part of the n-channel input signal, where m&#x3c;n, the signal enhancer having, for each channel signal part of said m-channel signal part, a non-linear anti-symmetric monotone transfer function. The audio reproducing device is further provided with a speech-music discriminator, which, in response to one of the channel signal parts of the m-channel signal part designated for speech, generates a control signal indicating the probability p that the one of the channel signal parts contains speech signals. This control signal is used to control the signal enhancer.

Audio reproducing device

A method and audio converter for generating further audio signals (u, u, u, u, u) from initial audio signal (x, x, x), wherein optionally an information signal (in means) is derived from said initial audio signals (x). On basis of the initial audio signal (x, x, x), a dominant signal y(k) and a residue signal (or signals) q(k), substantially transverse to each other, are determined (meansand). In at least two frequency ranges frequency components of the dominant signal are analysed (means), and a difference signal y({y(k)&#x2212;y(k)) corresponding to the dominant signal minus a frequency range component of the dominant signal in one or more frequency ranges (y(k)) is formed. The difference audio signal yand the residue signal q(k) are transformed into said further audio signal u(means), i.e. Preferably in said means () the frequency range component is also transformed differently from the difference signal y,with T&#x3b3;M.

Multi-channel audio converter

A multi-channel stereo converter is described comprising stereo magnitude determining means for generating a stereo information signal (a/b; &rgr;), which represents a degree of stereo between audio input signals (L, R), and transforming means for transforming said audio signals (L, R) based on said stereo information signal (a/b; &rgr;) into at least a surround signal (S). A space mapping interpretation is presented and an audio center signal may be derived from the stereo input signals as well. The result is more flexibility in application and design, without substantial cross talk in the audio signals.

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Groningen, Netherlands

Roy Irwan