Audio decoder and decoding method

Patent metadata

Field	Value
Publication number	US-12002480-B2
Application number	US-202318351769-A
Country	US
Kind code	B2
Filing date	Jul 13, 2023
Priority date	Aug 25, 2015
Publication date	Jun 4, 2024
Grant date	Jun 4, 2024

Abstract

A method for representing a second presentation of audio channels or objects as a data stream, the method comprising the steps of: (a) providing a set of base signals, the base signals representing a first presentation of the audio channels or objects; (b) providing a set of transformation parameters, the transformation parameters intended to transform the first presentation into the second presentation; the transformation parameters further being specified for at least two frequency bands and including a set of multi-tap convolution matrix parameters for at least one of the frequency bands.

First claim

What is claimed is:

1. A method of decoding an encoded audio signal, comprising:
receiving, by a decoder, an input bitstream;
dividing the input bitstream into a base signal bitstream and transformation parameter data;
decoding, by a base signal decoder, the base signal bitstream to provide frequency-domain signals having a plurality of subbands;
determining, in response to the transformation parameter data, a complex-valued convolution matrix, complex-valued, single-tap matrix coefficients, and real-valued matrix coefficients;
applying, by a first matrix multiplication unit, the complex-valued convolution matrix to a first subband of the frequency-domain signals;
applying, by a second matrix multiplication unit, the complex-valued, single-tap matrix coefficients to a second subband of the frequency-domain signals;
applying, by a third matrix multiplication unit, the real-valued matrix coefficients to one or more remaining subbands of the frequency-domain signals; and
converting, by a synthesis filterbank, output signals from the matrix multiplication units into a time-domain output.

2. A non-transitory computer-readable medium storing instructions that, when executed by a device, cause the device to perform operations comprising:
receiving, by a decoder, an input bitstream;
dividing the input bitstream into a base signal bitstream and transformation parameter data;
decoding, by a base signal decoder, the base signal bitstream to provide frequency-domain signals having a plurality of subbands;
determining, in response to the transformation parameter data, a complex-valued convolution matrix, complex-valued, single-tap matrix coefficients, and real-valued matrix coefficients;
applying, by a first matrix multiplication unit, the complex-valued convolution matrix to a first subband of the frequency-domain signals;
applying, by a second matrix multiplication unit, the complex-valued, single-tap matrix coefficients to a second subband of the frequency-domain signals;
applying, by a third matrix multiplication unit, the real-valued matrix coefficients to one or more remaining subbands of the frequency-domain signals; and
converting, by a synthesis filterbank, output signals from the matrix multiplication units into a time-domain output.

3. A system comprising:
a processor; and
a non-transitory computer-readable medium storing instructions that, when executed by the processor, cause the processor to perform operations comprising:
receiving, by a decoder, an input bitstream;
dividing the input bitstream into a base signal bitstream and transformation parameter data;
decoding, by a base signal decoder, the base signal bitstream to provide frequency-domain signals having a plurality of subbands;
determining, in response to the transformation parameter data, a complex-valued convolution matrix, complex-valued, single-tap matrix coefficients, and real-valued matrix coefficients;
applying, by a first matrix multiplication unit, the complex-valued convolution matrix to a first subband of the frequency-domain signals; applying, by a second matrix multiplication unit, the complex-valued, single-tap matrix coefficients to a second subband of the frequency-domain signals; applying, by a third matrix multiplication unit, the real-valued matrix coefficients to one or more remaining subbands of the frequency-domain signals; and converting, by a synthesis filterbank, output signals from the matrix multiplication units into a time-domain output.

Assignees

• Dolby Laboratories Licensing Corp
• Dolby Int Ab

Inventors

• Breebaart Dirk Jeroen
• Cooper David Matthew
• Samuelsson Leif Jonas

Classifications

• H04R2460/03

  Aspects of the reduction of energy consumption in hearing devices · CPC title

• G10L19/0212 Primary

  using orthogonal transformation · CPC title

• G10L19/0204

  using subband decomposition · CPC title

• 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

• H04S7/308 Primary

  Electronic adaptation dependent on speaker or headphone connection · CPC title