Apparatus and method for encoding and decoding spatial parameter

1. A spatial parameter encoding apparatus, comprising:

a valid range determination unit to determine a valid range of a spatial parameter using a correlation between input spatial parameters indicating a characteristic relationship between channels of a multi-channel audio signal;

a parameter quantization unit to quantize the spatial parameter based on the valid range; and

a parameter encoding unit to encode the quantized spatial parameter using at least one processor,

wherein the spatial parameter comprises an Inter-Channel Correlation (ICC) and an Inter-channel Phase Difference (IPD), and

wherein the correlation indicates a correlation between the ICC and the IPD.

2. The spatial parameter encoding apparatus of claim 1 , wherein the parameter quantization unit quantizes the spatial parameter using a joint quantization table including the valid range.

3. The spatial parameter encoding apparatus of claim 1 , further comprising:

a correlation setting unit to set a correlation with respect to input spatial parameters having no correlation with each other,

wherein the valid range determination unit determines the valid range based on the set correlation.

4. The spatial parameter encoding apparatus of claim 1 , wherein the valid range determination unit determines a valid range of an ICC for real numbers (ICC Re ) based on an ICC for signs (ICC) sign .

5. The spatial parameter encoding apparatus of claim 1 , wherein the valid range determination unit determines a valid range of an ICC for absolute values (ICC abs ), and a valid range of an ICC for signs (ICC) sign to which a sign of the IPD is applied.

6. The spatial parameter encoding apparatus of claim 1 , wherein, when the IPD is quantized to have two values, and is determined based on a sign of the ICC, the parameter encoding unit prevents transmitting of the IPD.

7. The spatial parameter encoding apparatus of claim 1 , wherein the parameter quantization unit quantizes the spatial parameter using a joint quantization table with respect to two input spatial parameters, by setting a use of only a minimum quantization operation based on the valid range.

8. The spatial parameter encoding apparatus of claim 1 , wherein the parameter quantization unit sets the valid range of the spatial parameter using a joint quantization table based on an intersection of inequalities to quantize the spatial parameter.

9. A spatial parameter decoding apparatus, comprising:

a spatial parameter decoding unit to decode an encoded spatial parameter;

a valid range determination unit to determine a valid range of a spatial parameter using a correlation between input spatial parameters indicating a characteristic relationship between channels of a multi-channel audio signal; and

a parameter dequantization unit to dequantize the spatial parameter based on the valid range using at least one processor,

wherein the spatial parameter comprises an Inter-Channel Correlation (ICC) and an Inter-channel Phase Difference (IPD), and

wherein the correlation indicates a correlation between the ICC and the IPD.

10. The spatial parameter decoding apparatus of claim 9 , wherein the parameter dequantization unit dequantizes the spatial parameter using a joint dequantization table including the valid range.

11. The spatial parameter decoding apparatus of claim 9 , further comprising:

a correlation setting unit to set a correlation with respect to input spatial parameters having no correlation with each other,

wherein the valid range determination unit determines the valid range based on the set correlation.

12. The spatial parameter decoding apparatus of claim 9 , wherein the valid range determination unit determines a valid range of an ICC for real numbers (ICC Re ).

13. The spatial parameter decoding apparatus of claim 9 , wherein the valid range determination unit determines a valid range of an ICC for absolute values (ICC abs ), and a valid range of an ICC for signs (ICC) sign to which a sign of the IPD is applied.

14. A spatial parameter encoding method, comprising:

determining a valid range of a spatial parameter using a correlation between spatial parameters indicating a characteristic relationship between channels of a multi-channel audio signal;

quantizing the spatial parameter based on the valid range; and

encoding the quantized spatial parameter using at least one processor,

wherein the spatial parameter comprises an Inter-Channel Correlation (ICC) and an Inter-channel Phase Difference (IPD), and

wherein the correlation indicates a correlation between the ICC and the IPD.

15. The spatial parameter encoding method of claim 14 , wherein the quantizing comprises quantizing the spatial parameter using a joint quantization table including the valid range.

16. The spatial parameter encoding method of claim 14 , further comprising:

setting a correlation with respect to input spatial parameters having no correlation with each other,

wherein the determining comprises determining the valid range based on the set correlation.

17. The spatial parameter encoding method of claim 14 , wherein the determining comprises determining a valid range of an ICC for real numbers (ICC Re ).

18. The spatial parameter encoding method of claim 14 , wherein the determining comprises determining a valid range of an ICC for absolute values (ICC abs ), and a valid range of an ICC for signs (ICC) sign to which a sign of the IPD is applied.

19. The spatial parameter encoding method of claim 14 , wherein the encoding comprises preventing transmission of the IPD, when the IPD is quantized to have two values, and is determined based on a sign of the ICC.

20. A spatial parameter decoding method, comprising:

decoding an encoded spatial parameter;

determining a valid range of a spatial parameter using a correlation between input spatial parameters indicating a characteristic relationship between channels of a multi-channel audio signal; and

dequantizing the spatial parameter based on the valid range using at least one processor,

wherein the spatial parameter comprises an Inter-Channel Correlation (ICC) and an Inter-channel Phase Difference (IPD), and

wherein the correlation indicates a correlation between the ICC and the IPD.

21. The spatial parameter decoding method of claim 20 , wherein the dequantizing comprises dequantizing the spatial parameter using a joint dequantization table including the valid range.

22. The spatial parameter decoding method of claim 20 , further comprising:

setting a correlation with respect to input spatial parameters having no correlation with each other,

wherein the determining comprises determining the valid range of the spatial parameter based on the set correlation.

23. The spatial parameter decoding method of claim 20 , wherein the determining comprises determining a valid range of an ICC for real numbers (ICC Re ).

24. The spatial parameter decoding method of claim 20 , wherein the determining comprises determining a valid range of an ICC for absolute values (ICC abs ), and a valid range of an ICC for signs (ICC) sign to which a sign of the IPD is applied.

25. At least one non-transitory computer readable medium storing computer readable instructions that control at least one processor to implement the method of claim 14 .

26. At least one non-transitory computer readable medium storing computer readable instructions that control at least one processor to implement the method of claim 20 .