ENCODING AND DECODING OF AUDIO OBJECTS

• US 20090326960A1
• Filed: 09/17/2007
• Published: 12/31/2009
• Est. Priority Date: 09/18/2006
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Breebaat, Dirk Jeroen
• Granted Patent: US 8,271,290 B2
• Time in Patent Office: Days
• US Class Current: 704/500
• 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 19/20 using sound class specific coding, hybrid encoders or object based coding

Abstract

An audio system comprises an encoder (209) which encodes audio objects in an encoding unit (403) that generates a down-mix audio signal and parametric data representing the plurality of audio objects. The down-mix audio signal and parametric data is transmitted to a decoder (215) which comprises a decoding unit (301) which generates approximate replicas of the audio objects and a rendering unit (303) which generates an output signal from the audio objects. The decoder (215) furthermore contains a processor (501) for generating encoding modification data which is sent to the encoder (209). The encoder (209) then modifies the encoding of the audio objects, and in particular modifies the parametric data, in response to the encoding modification data. The approach allows manipulation of the audio objects to be controlled by the decoder (215) but performed fully or partly by the encoder (209). Thus, the manipulation may be performed on the actual independent audio objects rather than on approximate replicas thereby providing improved performance.

Claims

1. An encoder for encoding audio objects, the encoder comprising:

means (401) for receiving a plurality of audio objects;

encoding means (403) for encoding the plurality of audio objects in a number of audio signals and parametric data representing the plurality of audio objects relative to the number of audio signals, the parametric data comprising a set of object parameters for at least one of the different audio objects;

means (409) for receiving encoding modification data from a remote unit; and

parameter means (405) for determining the parametric data in response to the encoding modification data.

2. The encoder of claim 1 wherein the encoding means is arranged to generate the number of audio signals by a down-mix of the audio objects and the parameter means (405) is arranged to modify a down-mix weight of at least one of the audio objects in response to the encoding modification data.

3. The encoder of claim 1 wherein the parameter means (405) is arranged to scale at least a first audio object in response to the encoding modification data and to modify object parameters for the first audio object in response to the scaling.

4. The encoder of claim 1 wherein at least some of the encoding modification data is frequency specific and the parameter means (405) is arranged to determine at least one object parameter in response to a frequency characteristic of the object parameter.

5. The encoder of claim 1 wherein the encoding means (403) is arranged to modify at least one audio object in response to the encoding modification data prior to a down-mix of the audio objects to the number of audio signals.

6. The encoder of claim 1 wherein the encoding means (403) is arranged to generate the number of audio signals as a spatial down-mix.

7. The encoder of claim 6 wherein the encoding means (403) is arranged to modify in response to the encoding modification data at least one characteristic selected from the group consisting of:

a spatial location of at least one of the audio objects;

a distance characteristic of at least one of the audio objects;

a spatial rendering mode of the encoder, and

a frequency characteristic of at least one of the audio objects.

8. The encoder of claim 1 wherein each audio object is associated with a set of audio sources which are independent of audio sources of other audio objects.

9. The encoder of claim 1 wherein the encoder is arranged to receive a first audio object from the remote unit and the means (409) for receiving the encoding modification data is arranged to extract the encoding modification data from encoding data received for the first audio object.

10. The encoder of claim 1 wherein the encoder is arranged to receive encoding modification data from a plurality of remote units and to generate different parametric data for the different remote units in response to receiving different encoding modification data from the different remote units.

11. A decoder for decoding audio objects, the decoder comprising:

a receiver (303) for receiving from an encoder a number of audio signals being a down-mix of a plurality of audio objects and parametric data representing the plurality of audio objects relative to the number of audio signals, the parametric data comprising a set of object parameters for at least one of the different audio objects;

decoding means (303) for decoding the audio objects from the number of audio signals in response to the parametric data;

rendering means (305) for generating a spatial multi-channel output signal from the audio objects;

means for generating (501) encoding modification data for the object encoder; and

means for transmitting (503) the encoding modification data to the object encoder.

22. An audio playing device (203) comprising a decoder (215) according to claim 11.

12. A teleconference hub for supporting a teleconference between a plurality of communication units, the teleconference hub comprising:

means (401) for receiving a first plurality of speech signals from the plurality of communication units;

encoding means (403) for encoding for a first communication unit the first plurality of speech signals in a number of audio signals and parametric data representing the plurality of speech signals relative to the number of audio signals, the parametric data comprising a set of object parameters for at least one of the different speech signals;

means for receiving (409) encoding modification data from the first communication unit; and

parameter means (405) for determining the parametric data in response to the modification data; and

means (407) for transmitting the number of audio signals and parametric data to the first communication unit.

13. A transmitter for transmitting audio signals, the transmitter comprising:

means (401) for receiving a plurality of audio objects;

encoding means (403) for encoding the plurality of audio objects in a number of audio signals and parametric data representing the plurality of audio objects relative to the number of audio signals, the parametric data comprising a set of object parameters for at least one of the different audio objects;

means for receiving (409) encoding modification data from a remote unit; and

parameter means (405) for determining the parametric data in response to the modification data.

14. A receiver for receiving audio signals, the receiver comprising:

a receiver element (303) for receiving from an encoder a number of audio signals being a down-mix of a plurality of audio objects and parametric data representing the plurality of audio objects relative to the number of audio signals, the parametric data comprising a set of object parameters for at least one of the different audio objects;

decoding means (303) for decoding the audio objects from the number of audio signals in response to the parametric data;

rendering means (305) for generating a spatial multi-channel output signal from the audio objects;

means (501) for generating encoding modification data for the object encoder; and

means (503) for transmitting the encoding modification data to the object encoder.

15. A communication system for communicating audio signals, the communication system comprising:

a transmitter (201) comprising;

means (401) for receiving a plurality of audio objects,

encoding means (403) for encoding the plurality of audio objects in a number of audio signals and parametric data representing the plurality of audio objects relative to the number of audio signals, the parametric data comprising a set of object parameters for at least one of the different audio objects, and

means (407) for transmitting the number of audio signals and the parametric data to a receiver; and

the receiver (203) comprising;

a receiver element (303) for receiving from the transmitter the number of audio signals and the parametric data,

decoding means (303) for decoding the audio objects from the number of audio signals in response to the parametric data,

rendering means (305) for generating a spatial multi-channel output signal from the audio objects,

means (501) for generating encoding modification data for the encoding means, and

means (503) for transmitting the encoding modification data to the transmitter;

and wherein the transmitter (201) comprises

means (409) for receiving the encoding modification data from the receiver;

parameter means (405) for determining the parametric data in response to the encoding modification data.

16. A method of encoding audio signals, the method comprising:

receiving (601) a plurality of audio objects;

encoding (603) the plurality of audio objects in a number of audio signals and parametric data representing the plurality of audio objects relative to the number of audio signals, the parametric data comprising a set of object parameters for at least one of the different audio objects;

receiving (605) encoding modification data from a remote unit; and

determining (603) the parametric data in response to the modification data.

21. A computer program product for executing the method of claim 16.

17. A method of decoding audio signals, the method comprising:

receiving (701) from an encoder a number of audio signals being a down-mix of a plurality of audio objects and parametric data representing the plurality of audio objects relative to the number of audio signals, the parametric data comprising a set of object parameters for at least one of the different audio objects;

decoding (703) the audio objects from the number of audio signals in response to the parametric data;

generating (705) a spatial multi-channel output signal from the audio objects;

generating (707) encoding modification data for the object encoder; and

transmitting (709) the encoding modification data to the object encoder.

18. A method of transmitting audio signals, the method comprising:

receiving (601) a plurality of audio objects;

encoding (603) the plurality of audio objects in a number of audio signals and parametric data representing the plurality of audio objects relative to the number of audio signals, the parametric data comprising a set of object parameters for at least one of the different audio objects;

receiving (605) encoding modification data from a remote unit;

determining (603) the parametric data in response to the modification data, and

transmitting the number of audio signals and parametric data.

19. A method of receiving audio signals, the method comprising:

receiving (701) from an encoder a number of audio signals being a down-mix of a plurality of audio objects and parametric data representing the plurality of audio objects relative to the number of audio signals, the parametric data comprising a set of object parameters for at least one of the different audio objects;

decoding (703) the audio objects from the number of audio signals in response to the parametric data;

generating (705) a spatial multi-channel output signal from the audio objects;

generating (707) encoding modification data for the object encoder; and

transmitting (709) the encoding modification data to the object encoder.

20. A method of transmitting and receiving audio signals, the method comprising:

a transmitter (101) performing the steps of;

receiving (601) a plurality of audio objects,

encoding (603) the plurality of audio objects in a number of audio signals and parametric data representing the plurality of audio objects relative to the number of audio signals, the parametric data comprising a set of object parameters for at least one of the different audio objects, and

transmitting the number of audio signals and the parametric data to a receiver; and

the receiver performing the steps of;

receiving (701) from the transmitter the number of audio signals and the parametric data;

decoding (703) the audio objects from the number of audio signals in response to the parametric data;

generating (705) a spatial multi-channel output signal from the audio objects;

generating (707) encoding modification data for the encoding means; and

transmitting (709) the encoding modification data to the object encoder;

and wherein the transmitter further performs the steps of;

receiving (605) the encoding modification data from the receiver, and

determining (603) the parametric data in response to the encoding modification data