Patent ID: 11937075
Assignee: FRAUNHOFER GESELLSCHAFT ZUR FÖRDERUNG DER ANGEWANDTEN FORSCHUNG E.V.
Field: Computer technology (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 2:
3. Apparatus for generating a sound field description using an input signal comprising a mono-signal or a multi-channel signal, the apparatus comprising:
an input signal analyzer for analyzing the input signal to derive direction data and diffuseness data;
a low-order components generator for generating a low-order sound field description from the input signal up to a predetermined order and mode, wherein the low-order components generator is configured to derive the low-order sound field description by copying or taking the input signal or performing a weighted combination of the channels of the input signal;
a mid-order components generator for generating a mid-order sound field description above the predetermined order or at the predetermined order and above the predetermined mode and below or at a high order using a synthesis of at least one direct portion and of at least one diffuse portion using the direction data and the diffuseness data so that the mid-order sound field description comprises a direct contribution and a diffuse contribution; and
a high-order components generator for generating a high-order sound field description comprising a component above the high order using a synthesis of at least one direct portion, wherein the high-order sound field description comprises a direct contribution only,
wherein the apparatus further comprises a sound field combiner for combining low-order sound field components of the low-order sound field description, mid-order sound field components of the mid-order sound field description and high-order sound field components of the high-order sound field description to obtain a combined sound field having (H+1)2 sound field components, wherein H is a maximum order of the generated sound field description, or
wherein the apparatus further comprises a directional gains calculator for calculating directional gains for mid-order sound field components of the mid-order sound field description and high-order sound field components of the high-order sound field description from the direction data and/or the diffuseness data and for feeding the directional gains for the mid-order sound field components to the mid-order components generator and for feeding the directional gains for the high-order sound field components to the high-order components generator, or
wherein the high-order components generator is configured to only synthesize a direct portion for a sound field component of the high-order sound field description using the direction data, and wherein the apparatus further comprises a directional gain calculator for the sound field component of the high-order sound field description configured for evaluating a spatial basis function for an order and a mode of the component of the high-order sound field description, wherein the high-order components generator is configured to derive the sound field component from a reference signal and the directional gain.