Method and apparatus for compressing and decompressing a higher order ambisonics signal representation

A high-level high-fidelity, stereo technology, applied in stereo systems, spatial/structural arrangements of speakers, features of broadcast information, etc., can solve problems such as directional power maximum shift, low spatial resolution, and blurred directional power distribution.

Active Publication Date: 2015-01-14
DOLBY INT AB
View PDF4 Cites 33 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0013] However, for direction estimation, both methods are constrained to the B format, which suffers from relatively low spatial resolution
Another disadvantage is that the estimation is restricted to only a single principal direction
The disadvantage of this method is that the presence of the ambient component will lead to blurring of the distribution of the directional power and will result in a shift of the maximum value of the directional power compared to the absence of any ambient component

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method and apparatus for compressing and decompressing a higher order ambisonics signal representation
  • Method and apparatus for compressing and decompressing a higher order ambisonics signal representation
  • Method and apparatus for compressing and decompressing a higher order ambisonics signal representation

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0059] Ambisonics signals use spherical harmonic (SH) expansions to describe the sound field in passive regions. The flexibility of this description can be attributed to the physical property that the temporal and spatial behavior of sound pressure is essentially determined by the wave equation.

[0060] Wave Equation and Spherical Harmonic Expansion

[0061] For a more detailed description of Ambisonics, a spherical coordinate system is assumed below, where the tilt angle θ ∈ [0 , π] and the azimuth φ∈[0, 2π] measured from the x-axis in the x=y plane to represent the space x=(r, θ, φ) T point in . In this spherical coordinate system, the wave equation for sound pressure p(t,x) (where t represents time) in a connected passive region is given by Earl G. Williams' textbook "Fourier Acoustics" (Applied Mathematical Sciences 93 Volume, Academic Press, 1999) gives:

[0062] 1 r 2 [ ∂ ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

Higher Order Ambisonics (HOA) represents a complete sound field in the vicinity of a sweet spot, independent of loudspeaker set-up. The high spatial resolution requires a high number of HOA coefficients. In the invention, dominant sound directions are estimated and the HOA signal representation is decomposed into dominant directional signals in time domain and related direction information, and an ambient component in HOA domain, followed by compression of the ambient component by reducing its order. The reduced-order ambient component is transformed to the spatial domain, and is perceptually coded together with the directional signals. At receiver side, the encoded directional signals and the order-reduced encoded ambient component are perceptually decompressed, the perceptually decompressed ambient signals are transformed to an HOA domain representation of reduced order, followed by order extension. The total HOA representation is re-composed from the directional signals, the corresponding direction information, and the original-order ambient HOA component.

Description

technical field [0001] The present invention relates to a method and apparatus for compressing and decompressing Higher Order Ambisonics signal representations, wherein the directional and ambient components are handled differently. Background technique [0002] Higher order Ambisonics (HOA) offers the advantage of capturing the complete sound field near a specific location in three-dimensional space, called the "sweet spot". Contrary to channel-based technologies like stereo or surround sound, this HOA representation is not tied to a specific loudspeaker configuration. However, this flexibility comes at the expense of the decoding process required to play back the HOA representation on a particular loudspeaker configuration. [0003] The HOA is based on the description of the complex magnitude of the air pressure for an individual angular wave quantity k at a position x near the desired listener position using a truncated spherical harmonic (SH) expansion, where, without l...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): H04H20/89
CPCH04S3/00G10L19/008H04S2420/11H04R5/02H04S3/008G10L19/20H04H20/89H04S3/02
Inventor A.克鲁格S.科唐J.贝姆J-M.巴特克
Owner DOLBY INT AB
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap