Method, medium, and system generating a stereo signal

Abstract

Surround audio decoding for selectively generating an audio signal from a multi-channel signal. In the surround audio decoding, a down-mixed signal, e.g., as down-mixed by an encoding terminal, is selectively up-mixed to a stereo signal or a multi-channel signal, by generating spatial information for generating the stereo signal, using spatial information for up-mixing the down-mixed signal to the multi-channel signal.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIGS. 1A and 1B illustrate conventional first and second 5-1-5 tree structures for decoding a multi-channel signal from a down-mixed signal, respectively;

FIG. 2A illustrates a stereo signal generating method, according to an embodiment of the present invention;

FIG. 2B illustrates a method for generating spatial information for up-mixing a down-mixed signal to a stereo signal, according to an embodiment of the present invention;

FIG. 3 illustrates a stereo signal spatial information generating component, according to an embodiment of the present invention; and

FIG. 4 illustrates a stereo outputting component, according to an embodiment the present invention.

Claims

1. A method for generating a stereo signal, comprising: generating spatial information for up-mixing a down-mixed signal to the stereo signal, using spatial information for up-mixing the down-mixed signal to a multi-channel signal other than the stereo signal; andup-mixing the down-mixed signal to the stereo signal using the generated spatial information.

2. The method of claim 1, wherein the spatial information for up-mixing the down-mixed signal to the multi-channel signal is pre-existing as generated by an encoder that down-mixed the down-mixed signal.

3. The method of claim 1, wherein the spatial information for the up-mixing of the down-mixed signal to the stereo signal includes information about an energy ratio or difference between predetermined channels in multi-channels.

4. The method of claim 3, wherein the generating of the spatial information for the up-mixing of the down-mixed signal to the stereo signal comprises: summing an energy sum of multi-channels corresponding to a left channel with a value obtained by multiplying energy of a front center channel by a predetermined value, as a left channel sum;summing an energy sum of multi-channels corresponding to a right channel with a value obtained by multiplying energy of a front center channel by another predetermined value, as a right channel sum; andgenerating the spatial information for the up-mixing of the down-mixed signal to the stereo signal using a ratio of the left and right channel sums.

5. The method of claim 4, wherein in the generating of the spatial information for the up-mixing of the down-mixed signal to the stereo signal, the spatial information for the up-mixing of the down-mixed signal to the stereo signal is generated using the following equation: CLD′=(PFL+PBL+a* PFC)/(PFR+PBR+b*PFC)where CLD′ is an energy ratio between channels included in the generated spatial information, PFL denotes energy of a front left (FL) channel, PBL denotes energy of a back left (BL) channel, PFC denotes energy of a front center (FC) channel, PFR denotes energy of a front right (FR) channel, PBR denotes energy of a back right (BR) channel, and a and b are constants.

6. The method of claim 1, wherein the spatial information for the up-mixing of the down-mixed signal to the stereo signal includes information about correlation or coherence between predetermined channels in multi-channels.

7. The method of claim 6, wherein, in the generating of the spatial information for the up-mixing of the down-mixed signal to the stereo signal, the spatial information for the up-mixing the down-mixed signal to the stereo signal is generated by linear interpolation, using the correlation or coherence between the predetermined channels in the multi-channels.

8. The method of claim 7, wherein, in the generating of the spatial information for the up-mixing of the down-mixed signal to the stereo signal, the spatial information for the up-mixing of the down-mixed signal to the stereo signal is generated using the following equation: ICC′=a*ICCa+(1−a)*ICCb where ICC′ denotes the correlation or coherence between the predetermined channels, ICCx denotes correlation or coherence of an OTTx module, and a is a constant.

9. The method of claim 7, wherein, in the generating of the spatial information for the up-mixing of the down-mixed signal to the stereo signal, the spatial information for the up-mixing of the down-mixed signal to the stereo signal is generated by searching within a table storing spatial information about an energy ratio or difference between the predetermined channels in the multi-channels or spatial information corresponding to the correlation or coherence between the predetermined channels in the multi-channels.

10. The method of claim 1, further comprising applying temporal processing (TP) or temporal envelope shaping (TES) to the stereo signal.

11. A method for generating an audio signal, comprising: selectively up-mixing a down-mixed signal to at least one of a multi-channel signal and a stereo signal,wherein up-mixing of the down-mixed signal to the multi-channel signal is accomplished through a multi-staged up-mixing of the down-mixed signal based upon spatial information for up-mixing the down-mixed signal to the multi-channel signal, andwherein up-mixing of the down-mixed signal to the stereo signal is accomplished by generating spatial information for the up-mixing of the down-mixed signal to the stereo signal based on the spatial information for up-mixing the down-mixed signal to a multi-channel signal and applying the generated spatial information to a single stage to up-mix the down-mixed signal to the stereo signal.

12. The method of claim 11, wherein selection of the up-mixing of the down-mixed signal to the at least one of the multi-channel signal and the stereo signal is based upon a number of speakers available in a corresponding decoding system or locations of available speakers among speakers included in the corresponding decoding system.

13. The method of claim 11, wherein the spatial information for the up-mixing of the down-mixed signal to the multi-channel signal is pre-existing as generated by an encoder that down-mixed the down-mixed signal.

14. At least one medium comprising computer readable code to control at least one processing element to implement the method of claim 1.

15. At least one medium comprising computer readable code to control at least one processing element to implement the method of claim 11.

16. An system for generating a stereo signal, comprising: a spatial information generator to generate spatial information for up-mixing a down-mixed signal to the stereo signal, using spatial information for up-mixing the down-mixed signal to a multi-channel signal other than the stereo signal; andan up-mixing unit to up-mix the down-mixed signal to the stereo signal, using the generated spatial information.

17. The system of claim 16, wherein the spatial information for up-mixing the down-mixed signal to the multi-channel signal is pre-existing as generated by an encoder that down-mixed the down-mixed signal.

18. The system of claim 16, wherein the spatial information for the up-mixing of the down-mixed signal to the stereo signal includes information about an energy ratio or difference between predetermined channels in multi-channels.

19. The system of claim 18, wherein the spatial information generator comprises: a first summing unit to sum an energy sum of channels corresponding to a left channel with a value obtained by multiplying energy of a front center channel by a predetermined value, as a left channel sum;a second summing unit summing an energy sum of channels corresponding to a right channel with a value obtained by multiplying energy of a front center channel by another predetermined value, as a right channel sum; andan information generator generating the spatial information for the up-mixing of the down-mixed signal to the stereo signal using a ratio of the left and right channel sums.

20. The system of claim 19, wherein the spatial information generator generates the spatial information for the up-mixing of the down-mixed signal to the stereo signal, using the following equation: CLD′=(PFL+PBL+a*PFC)/(PFR+PBR+b*PFC)where CLD′ denotes an energy ratio between channels included in the generated spatial information, PFL denotes energy of a front left (FL) channel, PBL denotes energy of a back left (BL) channel, PFC denotes energy of a front center (FC) channel, PFR denotes energy of a front right (FR) channel, PBR denotes energy of a back right (BR) channel, and a and b are constants.

21. The system of claim 16, wherein the spatial information for the up-mixing of the down-mixed signal to the stereo signal includes information about correlation or coherence between predetermined channels in multi-channels.

22. The system of claim 21, wherein the spatial information generator generates the spatial information for the up-mixing of the down-mixed signal to the stereo signal, by linear interpolation, using the correlation or coherence between the predetermined channels in the multi-channels.

23. The system of claim 22, wherein the spatial information generator generates the spatial information for the up-mixing of the down-mixed signal to the stereo signal, using the following equation: ICC′=a*ICCa+(1−a)*ICCb where ICC′ denotes the correlation or coherence between the predetermined channels, ICC0 denotes correlation or coherence of an OTTx module, and a is a constant.

24. The system of claim 21, wherein the spatial information generator generates the spatial information for the up-mixing of the down-mixed signal to the stereo signal, by searching for spatial information about an energy ratio or difference between the predetermined channels in the multi-channels or correlation or coherence between the predetermined channels in the multi-channels, from a table storing the spatial information about the energy ratio or difference between the predetermined channels in the multi-channels or the spatial information corresponding to the correlation or coherence between the predetermined channels in the multi-channels.

25. The system of claim 16, further comprising a TP/TES applying unit to apply temporal processing (TP) or temporal envelope shaping (TES) to the stereo signal.

26. An system for generating an audio signal, comprising: a plurality of up-mixing modules to selectively up-mix a down-mixed signal to at least one of a stereo signal and a multi-channel signal; anda spatial information generator to generate spatial information for up-mixing the down-mixed signal to the stereo signal, using spatial information for up-mixing the down-mixed signal to the multi-channel signal,wherein up-mixing of the down-mixed signal to the multi-channel signal is accomplished through staged up-mixing by the plurality of up-mixing modules based upon the spatial information for up-mixing the down-mixed signal to the multi-channel signal, andwherein up-mixing of the down-mixed signal to the stereo signal is accomplished through a single up-mixing by one of the plurality of up-mixing modules based upon the generated spatial information for the up-mixing of the down-mixed signal to the stereo signal.

27. The system of claim 26, wherein the selection of the up-mixing of the down-mixed signal to at least one of the multi-channel signal and the stereo signal is based upon a number of speakers available in a corresponding decoding system or locations of available speakers among speakers included in the corresponding decoding system.

28. The system of claim 26, wherein the spatial information for the up-mixing of the down-mixed signal to the multi-channel signal is pre-existing as generated by an encoder that down-mixed the down-mixed signal.