Distributed spatial audio decoder

• US 9,697,844 B2
• Filed: 01/07/2009
• Issued: 07/04/2017
• Est. Priority Date: 05/17/2006
• Status: Active Grant

• Current Assignee: Creative Technology Ltd.
• Original Assignee: Creative Technology Ltd.
• Inventors: Jot, Jean-Marc, Stein, Edward, Walsh, Martin
• Primary Examiner(s): Chin, Vivian
• Assistant Examiner(s): Tran, Con P
• Application Number:
  US12/350,047
• Publication Number:
  US 20090110204A1
• Time in Patent Office: 3,100 Days
• Field of Search: 381 77, 381 79, 381310, 381309, 381300, 381 22, 381 23, 381 17, 381 18, 381 20, 381 21, 381 80, 455 306
• CPC Class Codes: G10L 19/008 Multichannel audio signal coding or decoding using interchannel correlation to reduce redundancy, e.g. joint-stereo, intensity-coding or matrixing
• CPC Class Codes: G10L 19/16 Vocoder architecture
• CPC Class Codes: H04R 2205/024 Positioning of loudspeaker enclosures for spatial sound reproduction
• CPC Class Codes: H04R 2420/07 Applications of wireless loudspeakers or wireless microphones
• CPC Class Codes: H04S 5/005 of the pseudo five- or more-channel type, e.g. virtual surround

Abstract

This invention describes a method for decentralized decoding of a multichannel audio signal by broadcasting the original encoded data and distributing the decoding process between a plurality of receiving units. This allows for the design and manufacture of scalable multichannel audio reproduction systems having an arbitrary number of output channels, composed of a plurality of generic decoder and loudspeaker units each generating fewer output channels. With distributed decoding, a manufacturer can use “off-the-shelf” stereo or mono signal processors, digital-to-analog converters and amplifier components in each generic decoding module, thus reducing manufacturing costs and complexity requirements for each module while offering unlimited scalability in the total number of output channels.

Claims

1. A method for reproducing multichannel audio, comprising:

transmitting a multichannel audio encoded source signal to a plurality of decoder processing units in a decentralized decoder system for decentralized decoding of the multichannel audio source signal, each decoder processing unit in the plurality of decoder processing units including an output channel associated with a different physical location in a listening environment, each decoder processing unit being aware of its relative physical location in the listening environment,

wherein the decentralized decoder system is configured such that if an initial setup for the plurality of decoder processing units is modified, the decentralized decoder system can reconfigure parameters based on either detecting new positions and number of decoder processing units or detecting new positions and number of output channels in the modified setup,

wherein an output signal from each output channel is determined by the output channel position while the source signal is independent of the output channel positions in the listening environment, and wherein the output channel position is determined automatically.

2. The method of claim 1, further comprising:

receiving the multichannel audio encoded source signal by the plurality of decoder processing units; and

decoding the multichannel audio encoded source signal in determining and generating the output signal.

3. The method of claim 2, further comprising:

converting the output signal into a different signal type.

4. The method of claim 3, further comprising:

amplifying the converted output signal.

5. The method of claim 2, further comprising:

virtualizing the output signal.

6. The method of claim 1, wherein each output channel position corresponds to a loudspeaker position in the listening environment.

7. The method of claim 1, wherein the multichannel audio encoded source signal is 2-channel encoded material.

8. The method of claim 7, wherein the 2-channel encoded material is 2-channel phase-amplitude encoded material.

9. The method of claim 1, wherein the at least two output channels have corresponding positions on a common vertical axis in the listening environment.

10. The method of claim 1, wherein the at least two output channels have corresponding positions on different vertical axes in the listening environment.

11. A system for multichannel audio reproduction, comprising:

a distributed network of multichannel audio decoders in a decentralized decoder system for decentralized decoding of an encoded audio data stream, where each decoder is operable to receive an identical version of the encoded audio data stream and reproduce only the audio signals from the encoded audio data stream that are relevant for an associated loudspeaker with an identified physical location relative to a reference position in a listening environment, wherein the identified physical locations are detected and determined automatically and each loudspeaker is aware of its relative physical location in the listening environment,

wherein the decentralized decoder system is configured such that if an initial setup for the distributed network of multichannel audio decoders is modified, the decentralized decoder system can reconfigure parameters based on either detecting new positions and number of multichannel audio decoders or detecting new positions and number of loudspeakers in the modified setup.

12. The system of claim 11, further comprising:

a network of transaural filters for virtualizing the reproduced audio signals, the network of transaural filters being coupled to the distributed network of multichannel audio decoders.

13. The system of claim 11, wherein the distributed network of multichannel audio decoders are implemented in a wireless setup.

14. The system of claim 11, wherein the distributed network of multichannel audio decoders are implemented in a wired setup.

15. The system of claim 11, wherein the identified positions are determined prior to reproducing the audio signals.

16. The system of claim 11, wherein the multichannel audio decoders are frequency-domain phase-amplitude decoders.

17. The system of claim 11, wherein the encoded audio data stream is a 2-channel encoded material.

18. A method for reproducing a multichannel audio signal, comprising:

broadcasting via a wireless stereo audio transmitter a two-channel phase-amplitude encoded audio signal;

receiving, via a plurality of stereo wireless receivers in a decentralized decoder system for decentralized decoding of the encoded audio signal, the encoded audio signal; and

processing via a phase-amplitude stereo decoder the received audio signal, wherein the processing decodes only the audio signals relevant for at least two associated loudspeakers with different corresponding channels and identified physical locations in a listening environment, wherein the identified physical locations are detected and determined automatically and each loudspeaker is aware of its relative physical location in the listening environment,

wherein the decentralized decoder system is configured such that if an initial setup for the plurality of stereo wireless receivers is modified, the decentralized decoder system can reconfigure parameters based on either detecting new positions and number of stereo wireless receivers or detecting new positions and number of loudspeakers in the modified setup.

19. The method of claim 18, wherein the decoded audio signals are determined by the position of at least one loudspeaker relative to a reference position.

20. The method of claim 19, wherein each decoder is coupled to a network of transaural loudspeaker virtualization processors.