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

Patent metadata

Field	Value
Publication number	US-2016337775-A1
Application number	US-201615221354-A
Country	US
Kind code	A1
Filing date	Jul 27, 2016
Priority date	May 14, 2012
Publication date	Nov 17, 2016
Grant date	—

Abstract

A method and apparatus for decompressing a Higher Order Ambisonics (HOA) signal representation is disclosed. The apparatus includes an input interface that receives an encoded directional signal and an encoded ambient signal and an audio decoder that perceptually decodes the encoded directional signal and encoded ambient signal to produce a decoded directional signal and a decoded ambient signal, respectively. The apparatus further includes an extractor for obtaining side information related to the directional signal and an inverse transformer for converting the decoded ambient signal from a spatial domain to an HOA domain representation of the ambient signal. The apparatus also includes a synthesizer for recomposing a Higher Order Ambisonics (HOA) signal from the HOA domain representation of the ambient signal and the decoded directional signal. The side information includes a direction of the directional signal selected from a set of uniformly spaced directions.

First claim

1 . A method for decompressing a Higher Order Ambisonics (HOA) signal representation, the method comprising:
receiving an encoded directional signal and an encoded ambient signal; perceptually decoding the encoded directional signal and encoded ambient signal to produce a decoded directional signal and a decoded ambient signal, respectively; obtaining side information related to the directional signal; converting the decoded ambient signal from a spatial domain to an HOA domain representation of the ambient signal; recomposing a Higher Order Ambisonics (HOA) signal from the HOA domain representation of the ambient signal and the decoded directional signal; wherein the side information includes a direction of the directional signal selected from a set of uniformly spaced directions.

2 . The method of claim 1 wherein the converting includes applying an inverse spatial transform to the decoded ambient signal.

3 . The method of claim 1 wherein the Higher Order Ambisonics (HOA) signal representation has an order greater than one.

4 . The method of claim 3 wherein an order of the decoded ambient signal is less than the order of the Higher Order Ambisonics (HOA) signal representation.

5 . The method of claim 1 further comprising extending the order of the HOA domain representation of the ambient signal.

6 . The method of claim 5 wherein the order of the HOA domain representation of the ambient signal is extended to the order of the Higher Order Ambisonics (HOA) signal representation.

7 . The method of claim 5 wherein the order of the HOA domain representation of the ambient signal is extended to the order of the Higher Order Ambisonics (HOA) signal representation by appending signals with zero-valued samples.

8 . The method of claim 1 wherein the encoded directional signal, the encoded ambient signal, and the side information are received in a bit stream, and the bit stream is perceptually decoded into a plurality of transport channels with each of the plurality of transport channels being reassigned to a directional signal or an ambient signal before the converting and the recomposing.

9 . An apparatus for decompressing a Higher Order Ambisonics (HOA) signal representation, the apparatus comprising:
an input interface that receives an encoded directional signal and an encoded ambient signal; an audio decoder that perceptually decodes the encoded directional signal and encoded ambient signal to produce a decoded directional signal and a decoded ambient signal, respectively; an extractor for obtaining side information related to the directional signal; an inverse transformer for converting the decoded ambient signal from a spatial domain to an HOA domain representation of the ambient signal; a synthesizer for recomposing a Higher Order Ambisonics (HOA) signal from the HOA domain representation of the ambient signal and the decoded directional signal; wherein the side information includes a direction of the directional signal selected from a set of uniformly spaced directions.

10 . The apparatus of claim 9 wherein the converting includes applying an inverse spatial transform to the decoded ambient signal.

11 . The apparatus of claim 9 wherein the Higher Order Ambisonics (HOA) signal representation has an order greater than one.

12 . The apparatus of claim 11 wherein an order of the decoded ambient signal is less than the order of the Higher Order Ambisonics (HOA) signal representation.

13 . The apparatus of claim 9 further comprising extending the order of the HOA domain representation of the ambient signal.

14 . The apparatus of claim 13 wherein the order of the HOA domain representation of the ambient signal is extended to the order of the Higher Order Ambisonics (HOA) signal representation.

15 . The apparatus of claim 13 wherein the order of the HOA domain representation of the ambient signal is extended to the order of the Higher Order Ambisonics (HOA) signal representation by appending signals with zero-valued samples.

16 . The apparatus of claim 9 wherein the encoded directional signal, the encoded ambient signal, and the side information are received in a bit stream, and the bit stream is perceptually decoded into a plurality of transport channels with each of the plurality of transport channels being reassigned to a directional signal or an ambient signal before the converting and the recomposing.

17 . A non-transitory computer readable medium containing instructions that when executed by a processor perform the method of claim 1 .

Assignees

• Dolby Laboratories Licensing Corp

Inventors

• Krüger Alexander
• Kordon Sven
• Boehm Johannes
• Batke Johann-Markus

Classifications

• G10L19/008 Primary

  Multichannel audio signal coding or decoding using interchannel correlation to reduce redundancy, e.g. joint-stereo, intensity-coding or matrixing · CPC title

• H04S2420/11

  Application of ambisonics in stereophonic audio systems · CPC title

• H04S3/008 Primary

  in which the audio signals are in digital form, i.e. employing more than two discrete digital channels (data reduction aspects thereof based on psychoacoustics G10L19/02) · CPC title

• G10L19/20

  using sound class specific coding, hybrid encoders or object based coding · CPC title

• H04S3/02

  of the matrix type, i.e. in which input signals are combined algebraically, e.g. after having been phase shifted with respect to each other · CPC title