Reconstruction of audio scenes from a downmix

Patent metadata

Field	Value
Publication number	US-2025266048-A1
Application number	US-202519066143-A
Country	US
Kind code	A1
Filing date	Feb 27, 2025
Priority date	May 24, 2013
Publication date	Aug 21, 2025
Grant date	—

Abstract

Audio objects are associated with positional metadata. A received downmix signal comprises downmix channels that are linear combinations of one or more audio objects and are associated with respective positional locators.
In a first aspect, the downmix signal, the positional metadata and frequency-dependent object gains are received. An audio object is reconstructed by applying the object gain to an upmix of the downmix signal in accordance with coefficients based on the positional metadata and the positional locators.
In a second aspect, audio objects have been encoded together with at least one bed channel positioned at a positional locator of a corresponding downmix channel. The decoding system receives the downmix signal and the positional metadata of the audio objects. A bed channel is reconstructed by suppressing the content representing audio objects from the corresponding downmix channel on the basis of the positional locator of the corresponding downmix channel.

First claim

1 . A method for reconstructing a time frame of an audio scene with at least a plurality of N audio signals from a bitstream, the method comprising:
receiving the bitstream comprising the N audio signals signal, wherein N>1; decoding a downmix signal from the bitstream, the downmix signal comprising M downmix channels, wherein M>1 and each downmix channel is associated with a spatial locator of a plurality of spatial locators; and reconstructing the N audio signals based on as an inner product of a plurality of correlation coefficients and the downmix signal, wherein the correlation coefficients were predetermined.

2 . A computer program product comprising a non-transitory computer-readable medium encoded with instructions configured to cause one or more processing devices to perform the method of claim 1 .

3 . An audio decoding system configured to reconstruct a time frame of an audio scene with at least a plurality of N audio signals from a bitstream, the system comprising:
a receiver for receiving the bitstream comprising the N audio signals signal, wherein N>1; a decoder for decoding a downmix signal from the bitstream, the downmix signal comprising M downmix channels, wherein M>1 and each downmix channel is associated with a spatial locator of a plurality of spatial locators; and a reconstructor for reconstructing the N audio signals based on as an inner product of a plurality of correlation coefficients and the downmix signal, wherein the correlation coefficients were predetermined.

Assignees

• Dolby Int Ab

Inventors

• Hirvonen Toni
• Purnhagen Heiko
• Samuelsson Leif Jonas
• Villemoes Lars

Classifications

• H04S2400/03

  Aspects of down-mixing multi-channel audio to configurations with lower numbers of playback channels, e.g. 7.1 -> 5.1 (H04S2400/01 takes precedence) · 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

• H04S3/008

  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

• G10L25/06

  the extracted parameters being correlation coefficients · CPC title

• G10L19/0204

  using subband decomposition · CPC title