MULTI-CHANNEL AUDIO CODING

• US 20100153097A1
• Filed: 03/16/2006
• Published: 06/17/2010
• Est. Priority Date: 03/30/2005
• Status: Active Grant

• Current Assignee: Dolby International AB (Dolby Laboratories Incorporated), Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.), Koninklijke Philips N.V.
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Breebart, Dirk Jeroen, Petrus, Erik Gosuinus, Villemoes, Lars Falck, Purnhagen, Heiko, Hotho, Gerard Herman, Den Brinker, Albertus Cornelis, Roden, Karl Jonas
• Granted Patent: US 8,346,564 B2
• Time in Patent Office: Days
• US Class Current: 704/201
• 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: H04R 2420/07 Applications of wireless loudspeakers or wireless microphones
• CPC Class Codes: H04S 3/008 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

Abstract

A multi-channel audio encoder (10) for encoding a multi-channel audio signal (101), e.g. a 5.1 channel audio signal, into a spatial down-mix (102), e.g. a stereo signal, and associated parameters (104, 105). The encoder (10) comprises first and second units (110, 120). The first unit (110) encodes the multi-channel audio signal (101) into the spatial down-mix (102) and parameters (104). These parameters (104) enable a multi-channel decoder (20) to reconstruct the multi-channel audio signal (203) from the spatial down-mix (102). The second unit (120) generates, from the spatial down-mix (102), parameters (105) that enable the decoder to reconstruct the spatial down-mix (202) from an alternative down-mix (103), e.g. a so-called artistic down-mix that has been manually mixed in a sound studio. In this way, the decoder (20) can efficiently deal with a situation in which an alternative down-mix (103) is received instead of the regular spatial, down-mix (102). In the decoder (20), first the spatial down-mix (202) is reconstructed from the alternative down-mix (103) and the parameters (105). Next, the spatial down-mix (202) is decoded into the multi-channel audio signal (203).

Claims

1. A multi-channel audio encoder (10) for encoding N audio signals (101) into M audio signals (102) and associated parametric data (104, 105), M and N being integers, N>

M, M≧

1, wherein the multi-channel audio encoder (10) comprises;

a first unit (110) for encoding the N audio signals (101) into the M audio signals (102) and first associated parametric data (104), wherein the M audio signals (102) and the first associated parametric data (104) represent the N audio signals (101); and

a second unit (120) coupled to the first unit (110), the second unit (120) being arranged for generating, from the M audio signals (102), second associated parametric data (105) representing the M audio signals (102), the second associated parametric data comprising modification parameters enabling a reconstruction of the M audio signals (102) from K further audio signals (103) being an alternative downmix of the N audio signals (101) than the M audio signals (102), and wherein the associated parametric data (104, 105) comprise the first and second associated parametric data.

2. A multi-channel audio encoder (10) according to claim 1, wherein the second unit (120) is arranged for generating the second associated parametric data (105) such that the second associated parametric data (105) represent a property of the M audio signals (102).

4. A multi-channel audio encoder (10) according to claim 1, wherein the second unit (120) is arranged for generating, from the M audio signals (102) and from the K further audio signals (103), the second associated parametric data (105) such that the modification parameters represent a difference between the M audio signals (102) and the K further audio signals (103).

5. A multi-channel audio encoder (10) according to claim 1, wherein the second unit (120) is arranged for generating the second associated parametric data (105) such that the modification parameters comprise the property of the M audio signals (102) or a difference between the property of the M audio signals (102) and the property of the K further audio signals (103).

6. A multi-channel audio encoder (10) according to claim 2, wherein the second unit (120) is arranged for generating the second associated parametric data (105) such that the property comprises:

an energy or power value of at least part of the audio signals (102, 103);

or

a correlation value of at least part of the audio signals (102, 103);

or

a ratio between energy or power values of at least part of the audio signals (102, 103).

18. A transmission system (70) comprising a transmitter (40) for transmitting an encoded multi-channel audio signal via a transmission channel (30) to a receiver (50), the transmitter (40) comprising a multi-channel audio encoder (10) according to claim 1 for encoding N audio signals (101) into M audio signals (102) and associated parametric data (104, 105), the transmitter (40) further comprising means (41) for transmitting the K further audio signals (103) and the associated parametric data (104, 105) via the transmission channel (30) to the receiver (50), the receiver (50) comprising means (51) for receiving the K further audio signals (103) and the associated parametric data (104, 105), the receiver (50) further comprising a multi-channel audio decoder (20) for decoding the K further audio signals (103) and the associated parametric data (104, 105) into the N audio signals (203), the multi-channel audio decoder (20) comprising:

a first unit (210) for reconstructing M further audio signals (202) from the K audio signals (103) and at least a first part of the associated parametric data (105), comprising modification parameters enabling a reconstruction of the M further audio signals (202) from the audio signals (103), the M further audio signals (202) being an alternative down mix of the N audio channels (101) than the K audio channels (103) and M being an integer, M≧

1, wherein the first part of the associated parametric data (105) represents the M further audio signals (202); and

a second unit (220) coupled to the first unit (210), the second unit (220) being arranged for decoding the M further audio signals (202) and at least a second part of the associated parametric data (104) into the N audio signals (203), wherein the M further audio signals (202) and the second part of the associated parametric data (104) represent the N audio signals (203).

19. A transmitter (40) for transmitting an encoded multi-channel audio signal, the transmitter (40) comprising a multi-channel audio encoder (10) according to claim 1 for encoding N audio signals (101) into M audio signals (102) and associated parametric data (104, 105), the transmitter (40) further comprising means (41) for transmitting the K further audio signals (103) and the associated parametric data (104, 105).

25. A multi-channel audio recorder (60) comprising a multi-channel audio encoder (10) according to claim 1.

3. (canceled)

7. A multi-channel audio decoder (20) for decoding K audio signals (103) and associated parametric data (104, 105) into N audio signals (203), K and N being integers, N>

K, K≧

1, wherein the K audio signals (103) and the associated parametric data (104, 105) represent the N audio signals (203) and, and wherein the multi-channel audio decoder (20) comprises;

a first unit (210) for reconstructing M further audio signals (202) from the K audio signals (103) and at least a first part of the associated parametric data (105) comprising modification parameters enabling a reconstruction of the M further audio signals (202) from the K audio signals (103), the M further audio signals (202) being an alternative down mix of the N audio channels (101) than the K audio channels (103) and M being an integer, M≧

1, wherein the first part of the associated parametric data (105) represents the M further audio signals (202); and

a second unit (220) coupled to the first unit (210), the second unit (220) being arranged for decoding the M further audio signals (202) and at least a second part of the associated parametric data (104) into the N audio signals (203), wherein the M further audio signals (202) and the second part of the associated parametric data (104) represent the N audio signals (203).

8. A multi-channel audio decoder (20) according to claim 7, wherein the first part of the associated parametric data (105) represents a property of the M further audio signals (202).

10. A multi-channel audio decoder (20) according to claim 7, wherein the modification parameters comprise the property of the M further audio signals (202) or a difference between the property of the M further audio signals (202) and the property of the K audio signals (103).

11. A multi-channel audio decoder (20) according to claim 7, wherein the first unit (210) is arranged for generating, from the K audio signals (103), further modification parameters representing the K audio signals (103), and wherein the first unit (210) is further arranged for reconstructing the M further audio signals (202) from the K audio signals (103) and the modification parameters comprised in the first part of the associated parametric data (105) and the further modification parameters.

12. A multi-channel audio decoder (20) according to claim 11, wherein the modification parameters comprise the property of the M further audio signals (202), and wherein the further modification parameters comprise the property of the K audio signals (103), and wherein the first unit (210) is arranged for reconstructing the M further audio signals (202) from the K audio signals (103) and a difference between the property of the M further audio signals (202) and the property of the K audio signals (103).

13. A multi-channel audio decoder (20) according to claim 8, wherein the property comprises:

an energy or power value of at least part of the audio signals (103, 202);

or

a correlation value of at least part of the audio signals (103, 202);

or

a ratio between energy or power values of at least part of the audio signals (103, 202).

20. A receiver (50) for receiving an encoded multi-channel audio signal, the receiver (50) comprising means (51) for receiving K audio signals (103) and associated parametric data (104, 105), the receiver (50) further comprising a multi-channel audio decoder (20) according to claim 7 for decoding the K audio signals (103) and the associated parametric data (104, 105) into N audio signals (203).

24. A multi-channel audio player (60) comprising a multi-channel audio decoder (20) according to claim 7.

9. (canceled)

14. A method of encoding N audio signals (101) into M audio signals (102) and associated parametric data (104, 105), M and N being integers, N>

M, M≧

1, wherein the method comprises;

encoding the N audio signals (101) into the M audio signals (102) and first associated parametric data (104), wherein the M audio signals (102) and the first associated parametric data (104) represent the N audio signals (101); and

generating, from the M audio signals (102), second associated parametric data (105) representing the M audio signals (102), the second associated parametric data comprising modification parameters enabling a reconstruction of the M audio signals (102) from K further audio signals (103) being an alternative downmix of the N audio signals (101) than the M audio signals (102), and wherein the associated parametric data (104, 105) comprise the first and second associated parametric data.

26. A computer program product operative to cause a processor to perform the steps of the method as claimed in claim 14.

15. A method of decoding K audio signals (103) and associated parametric data (104, 105) into N audio signals (203), K and N being integers, N>

K, K≧

1, wherein the K audio signals (103) and the associated parametric data (104, 105) represent the N audio signals (203), and wherein the method comprises;

reconstructing M further audio signals (202) from the K audio signals (103) and at least a first part of the associated parametric data (105) comprising modification parameters enabling a reconstruction of the M further audio signals (202) from the K audio signals (103), the M further audio signals (202) being an alternative down mix of the N audio channels (101) than the K audio channels 103 and M being an integer, M≧

1, wherein the first part of the associated parametric data (105) represents the M further audio signals (202); and

decoding the M further audio signals (202) and at least a second part of the associated parametric data (104) into the N audio signals (203), wherein the M further audio signals (202) and the second part of the associated parametric data (104) represent the N audio signals (203).

16. An encoded multi-channel audio signal comprising K audio signals (103) and associated parametric data (104, 105), wherein the K audio signals (103) and the associated parametric data (104, 105) represent N audio signals (101), K and N being integers, N>

K, K≧

1, and wherein the associated parametric data (104, 105) comprise first and second parts, wherein the first part of the associated parametric data (105) represents M further audio signals (202) and comprises modification parameters enabling a reconstruction of the M further audio signals (202) from the K audio signals (103), the M further audio signals (202) being an alternative down mix of the N audio channels (101) than the K audio channels (103) and M being an integer, M≧

1, and wherein the M further audio signals (202) and the second part of the associated parametric data (104) represent the N audio signals (101).

17. A storage medium having stored thereon a signal according to claim 16.

21. A method of transmitting and receiving an encoded multi-channel audio signal, the method comprising encoding N audio signals (101) into M audio signals (102) and associated parametric data (104, 105), M and N being integers, N>

M, M≧

1, wherein the encoding comprises;

encoding the N audio signals (101) into the M audio signals (102) and first associated parametric data (104), wherein the M audio signals (102) and the first associated parametric data (104) represent the N audio signals (101); and

generating, from the M audio signals (102), second associated parametric data (105) representing the M audio signals (102), the second associated parametric data comprising modification parameters enabling a reconstruction of the M audio signals (102) from K further audio signals (103) being an alternative downmix of the N audio signals (101) than the M audio signals (102), wherein the associated parametric data (104, 105) comprise the first and second associated parametric data,

the method further comprising transmitting and receiving the K audio signals (103) and the associated parametric data (104, 105), decoding the K audio signals (103) and the associated parametric data (104, 105) into the N audio signals (203), the decoding comprising;

reconstructing M further audio signals (202) from the K audio signals (103) and at least a first part of the associated parametric data (105), wherein the first part of the associated parametric data (105) represents the M further audio signals (202) and comprises the modification parameters; and

decoding the M further audio signals (202) and at least a second part of the associated parametric data (104) into the N audio signals (203), wherein the M further audio signals (202) and the second part of the associated parametric data (104) represent the N audio signals (203).

22. A method of transmitting an encoded multi-channel audio signal, the method comprising encoding N audio signals (101) into M audio signals (102) and associated parametric data (104, 105), M and N being integers, N>

M, M≧

1, wherein the encoding comprises;

encoding the N audio signals (101) into the M audio signals (102) and first associated parametric data (104), wherein the M audio signals (102) and the first associated parametric data (104) represent the N audio signals (101); and

generating, from the M audio signals (102), second associated parametric data (105) representing the M audio signals (102), the second associated parametric data comprising modification parameters enabling a reconstruction of the M audio signals (102) from K further audio signals (103) being an alternative downmix of the N audio signals (101) than the M audio signals (102), wherein the associated parametric data (104, 105) comprise the first and second associated parametric data,

the method further comprising transmitting the K further audio signals (103) and the associated parametric data (104, 105).

23. A method of receiving an encoded multi-channel audio signal, the method comprising receiving K audio signals (103) and associated parametric data (104, 105) and decoding the K audio signals (103) and the associated parametric data (104, 105) into N audio signals (203), K and N being integers, N>

K, K≧

1, wherein the K audio signals (103) and the associated parametric data (104, 105) represent the N audio signals (203), and wherein the decoding comprises;

reconstructing M further audio signals (202) from the K audio signals (103) and at least a first part of the associated parametric data (105) comprising modification parameters enabling a reconstruction of the M further audio signals (202) from the K audio signals (103), the M further audio signals (202) being an alternative down mix of the N audio channels (101) than the K audio channels (103) and M being an integer, M≧

1, wherein the first part of the associated parametric data (105) represents the M further audio signals (202); and

decoding the M further audio signals (202) and at least a second part of the associated parametric data (104) into the N audio signals (203), wherein the M further audio signals (202) and the second part of the associated parametric data (104) represent the N audio signals (203).