Method and device for audio signal processing
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, each of the multi-audio signals including a plurality of subband signals, and the plurality of subband signals including a signal of a first subband group having low frequencies and a signal of a second subband group having high frequencies based on a predetermined frequency band; receiving at least one parameter corresponding to each subband signal of the second subband group, the at least one parameter being extracted from binaural room impulse response (BRIR) subband filter coefficients corresponding to each subband signal of the second subband group; and performing tap-delay line filtering of the subband signal of the second subband group by using the received parameter and an apparatus for processing an audio signal using the same.
1. A method for processing an audio signal, the method comprising:
receiving an input audio signal including a plurality of subband signals, wherein the plurality of subband signals include a first subband group containing only low-frequency subband signals determined based on a predetermined frequency band and a second subband group containing only high-frequency subband signals determined based on the predetermined frequency band;
performing a first filtering on each subband signal of the first subband group; and
performing a second filtering on each subband signal of the second subband group, wherein the second filtering is distinct from the first filtering,
wherein the first filtering is performed by using a first parameter set including one or more parameters for a corresponding subband and the second filtering is performed by using a second parameter set including one or more parameters for a corresponding subband,
wherein characteristics of the first parameter set is different from characteristics of the second parameter set,
wherein the second parameter set includes a set of gain and delay for the corresponding subband, and
wherein the second filtering comprises performing one-tap-delay line filtering on each subband signal of the second subband group by using the set of gain and delay for the corresponding subband.
2. The method of claim 1 , wherein the number of one or more parameters of a second parameter set for a subband of the first subband group is equal to or less than the number of one or more parameters of a first parameter set for a subband of the first subband group.
3. The method of claim 1 , wherein the first parameter set includes a set of subband filter coefficients obtained as at least a portion of proto-type subband filter coefficients for the corresponding subband, and
wherein the first filtering comprises performing fast convolution on each subband signal of the first subband group by using the set of subband filter coefficients for the corresponding subband.
4. The method of claim 3 , wherein the proto-type subband filter coefficients are binaural room impulse response (BRIR) subband filter coefficients.
5. The method of claim 1 , wherein the set of gain and delay is extracted from BRIR subband filter coefficients for the corresponding subband.
6. The method of claim 5 , wherein the delay indicates positional information for a maximum peak in the BRIR subband filter coefficients.
7. The method of claim 1 , wherein the gain has a complex value.
8. The method of claim 1 , further comprising:
combining filtered subband signals of the first subband group and filtered subband signals of the second subband group into 2-channel left and right signals; and
performing a QMF-synthesis on the combined 2-channel left and right signals.
9. An apparatus for processing an audio signal, the apparatus comprising:
a binaural renderer configured to perform binaural rendering on an input audio signal,
wherein the binaural renderer is configured to:
receive an input audio signal including a plurality of subband signals, wherein the plurality of subband signals include a first subband group containing only low-frequency subband signals determined based on a predetermined frequency band and a second subband group containing only high-frequency subband signals determined based on the predetermined frequency band,
perform a first filtering on each subband signal of the first subband group, and
perform a second filtering on each subband signal of the second subband group, wherein the second filtering is distinct from the first filtering,
wherein the first filtering is performed by using a first parameter set including one or more parameters for a corresponding subband and the second filtering is performed by using a second parameter set including one or more parameters for a corresponding subband,
wherein characteristics of the first parameter set is different from characteristics of the second parameter set,
wherein the second parameter set includes a set of gain and delay for the corresponding subband, and
wherein the second filtering comprises performing one-tap-delay line filtering on each subband signal of the second subband group by using the set of gain and delay for the corresponding subband.
10. The apparatus of claim 9 , wherein the number of one or more parameters of a second parameter set for a subband of the first subband group is equal to or less than the number of one or more parameters of a first parameter set for a subband of the first subband group.
11. The apparatus of claim 9 , wherein the first parameter set includes a set of subband filter coefficients obtained as at least a portion of proto-type subband filter coefficients for the corresponding subband, and
wherein the first filtering comprises performing fast convolution on each subband signal of the first subband group by using the set of subband filter coefficients for the corresponding subband.
12. The apparatus of claim 11 , wherein the proto-type subband filter coefficients are binaural room impulse response (BRIR) subband filter coefficients.
13. The apparatus of claim 9 , wherein the set of gain and delay is extracted from BRIR subband filter coefficients for the corresponding subband.
14. The apparatus of claim 13 , wherein the delay indicates positional information for a maximum peak in the BRIR subband filter coefficients.
15. The apparatus of claim 9 , wherein the gain has a complex value.
16. The apparatus of claim 9 , wherein the binaural renderer is further configured to:
combine filtered subband signals of the first subband group and filtered subband signals of the second subband group into 2-channel left and right signals, and
perform a QMF-synthesis on the combined 2-channel left and right signals.