Method and apparatus for processing audio signals
The present invention relates to a method and an apparatus for processing a signal, which are used for effectively reproducing an audio signal, and more particularly, to a method and an apparatus for processing a signal, which are used for implementing binaural rendering for reproducing multi-channel or multi-object audio signals in stereo with a low calculation amount. To this end, provided are a method for processing an audio signal including: receiving multi-audio signals including multi-channel or multi-object signals; receiving truncated subband filter coefficients for filtering the multi-audio signals, the truncated subband filter coefficients being at least a portion of subband filter coefficients obtained from a binaural room impulse response (BRIR) filter coefficient for binaural filtering of the multi-audio signals, and the lengths of the truncated subband filter coefficients being determined based on filter order information obtained by at least partially using characteristic information extracted from the corresponding subband filter coefficients; and filtering the subband signal by using the truncated subband filter coefficients corresponding to each subband signal of the multi-audio signals and an apparatus for processing an audio signal using the same.
1. An apparatus for performing binaural rendering for an input audio signal, the apparatus comprising:
a fast convolution unit configured to perform filtering each of a first group of subband signals of the input audio signal; and
a tap-delay line processing unit configured to perform tap-delay line filtering each of a second group of subband signals of the input audio signal,
wherein the fast convolution unit performs the filtering by using a plurality of sets of subband filter coefficients corresponding to the first group of subband signals, respectively, and each set of subband filter coefficients has an independent length determined according to a corresponding subband.
2. The apparatus of claim 1 , wherein each set of subband filter coefficients includes at least one subband filter coefficient and a length of a set of subband filter coefficients of at least one subband is different from a length of a set of subband filter coefficients of another subband.
3. The apparatus of claim 1 , wherein each set of subband filter coefficients used for the filtering is truncated from a corresponding set of proto-type subband filter coefficients, and a length of the truncation is determined based on filter order information obtained by at least partially using characteristic information extracted from the corresponding set of proto-type subband filter coefficients.
4. The apparatus of claim 3 , wherein the characteristic information includes first reverberation time information of the corresponding set of proto-type subband filter coefficients, and the filter order information has a single value for each subband.
5. The apparatus of claim 3 , wherein the corresponding set of proto-type subband filter coefficients is obtained from a set of binaural room impulse response (BRIR) filter coefficients corresponding to the input audio signal.
6. The apparatus of claim 1 , wherein the first group of subband signals have low frequencies based on a predetermined frequency band and the second group of subband signals have high frequencies based on the predetermined frequency band.
7. The apparatus of claim 1 , wherein the tap-delay line processing unit performs tap-delay line filtering by using subband parameters extracted from the corresponding set of proto-type subband filter coefficients.
8. The apparatus of claim 7 , wherein the subband parameters include delay information for the corresponding set of proto-type subband filter coefficients and gain information corresponding to the delay information.
9. A method for processing an audio signal, the method comprising:
receiving an input audio signal;
filtering each of a first group of subband signals of the input audio signal by using a plurality of sets of subband filter coefficients corresponding to the first group of the subband signals, respectively, wherein each set of subband filter coefficients has an independent length determined according to a corresponding subband; and
filtering each of a second group of subband signals of the input audio signal by using tap-delay line filtering.
10. The method of claim 9 , wherein each set of subband filter coefficients includes at least one subband filter coefficient and a length of a set of subband filter coefficients of at least one subband is different from a length of a set of subband filter coefficients of another subband.
11. The method of claim 9 , wherein each set of subband filter coefficients used for the filtering is truncated from a corresponding set of proto-type subband filter coefficients, and a length of the truncation is determined based on filter order information obtained by at least partially using characteristic information extracted from the corresponding set of proto-type subband filter coefficients.
12. The method of claim 11 , wherein the characteristic information includes first reverberation time information of the corresponding set of proto-type subband filter coefficients, and the filter order information has a single value for each subband.
13. The method of claim 11 , wherein the corresponding set of proto-type subband filter coefficients is obtained from a set of binaural room impulse response (BRIR) filter coefficients corresponding to the input audio signal.
14. The method of claim 9 , wherein the first group of subband signals have low frequencies based on a predetermined frequency band and the second group of subband signals have high frequencies based on the predetermined frequency band.
15. The method of claim 9 , the tap-delay line filtering is performed by using subband parameters extracted from the corresponding set of proto-type subband filter coefficients.
16. The method of claim 15 , wherein the subband parameters include delay information for the corresponding set of proto-type subband filter coefficients and gain information corresponding to the delay information.