Methods and devices for joint multichannel coding

Patent metadata

Field	Value
Publication number	US-10083701-B2
Application number	US-201715647076-A
Country	US
Kind code	B2
Filing date	Jul 11, 2017
Priority date	Sep 12, 2013
Publication date	Sep 25, 2018
Grant date	Sep 25, 2018

Abstract

Encoding and decoding devices for encoding the channels of an audio system having at least four channels are disclosed. The decoding device has a first stereo decoding component which subjects a first pair of input channels to a first stereo decoding, and a second stereo decoding component which subjects a second pair of input channels to a second stereo decoding. The results of the first and second stereo decoding components are crosswise coupled to a third and a fourth stereo decoding component which each performs stereo decoding on one channel resulting from the first stereo decoding component, and one channel resulting from the second stereo decoding component.

First claim

What is claimed is:

1. A decoding method in a multichannel audio system comprising M audio channels, wherein M is at least 3, the method comprising:
receiving M input audio channels;
subjecting a first pair of audio channels, from the M input audio channels, to a first stereo decoding so as to obtain two stereo decoded audio channels, wherein the stereo decoded audio channels obtained from the first stereo decoding form, together with M−2 of the input audio channels not included in the first pair of audio channels, a first set of M audio channels; and
for each integer n from 2 to N, wherein N is at least 2:
subjecting an nth pair of audio channels, from the (n−1)th set of M audio channels, to an nth stereo decoding so as to obtain two stereo decoded audio channels, wherein the stereo decoded audio channels obtained from the nth stereo decoding form, together with M−2 of the audio channels from the (n−1)th set of M audio channels not included in the nth pair of audio channels, an nth set of M audio channels,
the method further comprising:
outputting the Nth set of M audio channels,
wherein at least one of the pairs of audio channels subjected to stereo decoding includes an audio channel resulting from one of the stereo decodings, and wherein at least two of the stereo decodings include forming, for at least one frequency band and at least one time frame, linear combinations of the two audio channels subjected to the respective stereo decoding.

2. The method of claim 1 , wherein at least two of the stereo decodings include forming, for at least one frequency band and at least one time frame, a weighted or non-weighted sum of the two audio channels subjected to the respective stereo decoding and a weighted or non-weighted difference between the two audio channels subjected to the respective stereo decoding.

3. The method of claim 1 , wherein M is at least 4.

4. The method of claim 1 , wherein N is at least 4.

5. The method of claim 1 , wherein N is at least 4 and M is at least 4, wherein the second pair of audio channels includes two of the M input audio channels, wherein the third pair of audio channels includes a first channel resulting from the first stereo decoding and a first channel resulting from the second stereo decoding, and wherein the fourth pair of audio channels includes an audio channel associated with a second audio channel resulting from the first stereo decoding and a second audio channel resulting from the second stereo decoding.

6. The method of claim 5 , wherein the audio channel associated with a second channel resulting from the first stereo decoding is the second audio channel resulting from the first stereo decoding or an audio channel resulting from a fifth stereo decoding of a fifth input audio channel and the second audio channel resulting from the first stereo decoding.

7. The method of claim 1 , further comprising:
receiving signaling indicating a coding configuration to be used when decoding,
wherein the pairs of audio channels subjected to stereo decoding are selected in accordance with the indicated coding configuration.

8. The method of claim 1 , further comprising receiving side information, and, for each of the stereo decodings:
selecting, based on the side information, a coding scheme to apply; and performing stereo decoding according to the selected coding scheme.

9. A computer program product comprising a non-transitory computer-readable medium with instructions for performing a decoding method, the method comprising:
receiving M input audio channels, wherein M is at least 3;
subjecting a first pair of audio channels, from the M input audio channels, to a first stereo decoding so as to obtain two stereo decoded audio channels, wherein the stereo decoded audio channels obtained from the first stereo decoding form, together with M−2 of the input audio channels not included in the first pair of audio channels, a first set of M audio channels; and
for each integer n from 2 to N, wherein N is at least 2:
subjecting an nth pair of audio channels, from the (n−1)th set of M audio channels, to an nth stereo decoding so as to obtain two stereo decoded audio channels, wherein the stereo decoded audio channels obtained from the nth stereo decoding form, together with M−2 of the audio channels from the (n−1)th set of M audio channels not included in the nth pair of audio channels, an nth set of M audio channels,
the method further comprising:
outputting the Nth set of M audio channels,
wherein at least one of the pairs of audio channels subjected to stereo decoding includes an audio channel resulting from one of the stereo decodings, and wherein at least two of the stereo decodings include forming, for at least one frequency band and at least one time frame, linear combinations of the two audio channels subjected to the respective stereo decoding.

10. A decoding device in a multichannel audio system comprising M audio channels, wherein M is at least 3, the device comprising:
a receiver that receives M input audio channels;
N stereo decoders, wherein N is at least 2; and
an output,
wherein a first stereo decoder of the N stereo decoders subjects a first pair audio channels, from the M input audio channels, to a first stereo decoding, and obtains two stereo decoded audio channels, wherein the stereo decoded audio channels obtained from the first stereo decoding form, together with M−2 of the input audio channels not included in the first pair of audio channels, a first set of M audio channels,
wherein, for each integer n from 2 to N, an nth stereo decoder of the N stereo decoders subjects an nth pair of audio channels, from the (n−1)th set of M audio channels, to an nth stereo decoding, and obtains two stereo decoded audio channels, wherein the stereo decoded audio channels obtained from the nth stereo decoding form, together with M−2 of the audio channels from the (n−1)th set of M audio channels not included in the nth pair of audio channels, an nth set of M audio channels,
wherein the outputter outputs the Nth set of M audio channels,
wherein at least one of the pairs of audio channels subjected to stereo decoding includes an audio channel resulting from one of the stereo decodings, and
wherein at least two of the stereo decodings include forming, for at least one frequency band and at least one time frame, linear combinations of the two audio channels subjected to the respective stereo decoding.

11. An audio system comprising a device according to claim 10 .

12. An encoding method in a multichannel audio system comprising M audio channels, wherein M is at least 3, the method comprising
receiving M input audio channels;
subjecting a first pair of audio channels, from the M input audio channels, to a first stereo encoding so as to obtain two stereo encoded audio channels, wherein the stereo encoded audio channels obtained from the first stereo encoding form, together with M−2 of the input audio channels not included in the first pair of audio channels, a first set of M audio channels; and
for each integer n from 2 to N, where N is at least 2:
subjecting an nth pair of audio channels, from the (n−1)th set of M audio channels, to an nth stereo encoding so as to obtain two stereo encoded audio channels, wherein the stereo encoded audio channels obtained from the nth stereo encoding form, together with M−2 of the audio channels from the (n−1)th set of M audio channels not included in the nth pair of audio channels, an nth set of M audio channels,
the encoding method further comprising:
outputting the Nth set of M audio channels,
wherein at least one of the pairs of audio channels subjected to stereo encoding includes an audio

Assignees

• Dolby Int Ab

Inventors

• Kjoerling Kristofer
• Mundt Harald
• Purnhagen Heiko

Classifications

• G10L19/20

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

• H04S2400/01

  Multi-channel, i.e. more than two input channels, sound reproduction with two speakers wherein the multi-channel information is substantially preserved · CPC title

• 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