Audio signal processing method and apparatus
The present invention relates to a method and an apparatus for processing an audio signal, and more particularly, to a method and an apparatus for processing an audio signal, which synthesize an object signal and a channel signal and effectively perform binaural rendering of the synthesized signal. To this end, provided are a method for processing an audio signal, which includes: receiving an input audio signal including a multi-channel signal; receiving truncated subband filter coefficients for filtering the input audio signal, the truncated subband filter coefficients being at least some of subband filter coefficients obtained from binaural room impulse response (BRIR) filter coefficients for binaural filtering of the input audio signal and the length of the truncated subband filter coefficients being determined based on filter order information obtained by at least partially using reverberation time information extracted from the corresponding subband filter coefficients; obtaining vector information indicating the BRIR filter coefficients corresponding to each channel of the input audio signal; and filtering each subband signal of the multi-channel signal by using the truncated subband filter coefficients corresponding to the relevant channel and subband based on the vector information and an apparatus for processing an audio signal by using the same.
1. A method for processing an audio signal, the method comprising:
receiving an input audio signal including a multi-channel signal;
receiving truncated subband filter coefficients for filtering the input audio signal, the truncated subband filter coefficients being at least some of subband filter coefficients obtained from binaural room impulse response (BRIR) filter coefficients for binaural filtering of the input audio signal and the length of the truncated subband filter coefficients being determined based on filter order information obtained by at least partially using reverberation time information extracted from the corresponding subband filter coefficients;
obtaining vector information indicating the BRIR filter coefficients corresponding to each channel of the input audio signal; and
filtering each subband signal of the multi-channel signal by using the truncated subband filter coefficients corresponding to the relevant channel and subband based on the vector information.
2. The method of claim 1 , wherein when BRIR filter coefficients having positional information matching with positional information of a specific channel of the input audio signal are present in a BRIR filter set, the vector information indicates the relevant BRIR filter coefficients as BRIR filter coefficients corresponding to the specific channel.
3. The method of claim 1 , wherein when BRIR filter coefficients having positional information matching with positional information of a specific channel of the input audio signal are not present in a BRIR filter set, the vector information indicates BRIR filter coefficients having a minimum geometric distance from the positional information of the specific channel as BRIR filter coefficients corresponding to the specific channel.
4. The method of claim 3 , wherein the geometric distance is a value obtained by aggregating an absolute value of an altitude deviation between two positions and an absolute value of an azimuth deviation between the two positions.
5. The method of claim 1 , wherein the length of at least one truncated subband filter coefficients is different from the length of truncated subband filter coefficients of another subband.
6. An apparatus for processing an audio signal for performing binaural rendering for an input audio signal, the apparatus comprising:
a parameterization unit configured to generate a filter for the input audio signal; and
a binaural rendering unit configured to receive the input audio signal including a multi-channel signal and filter the input audio signal by using parameters generated by the parameterization unit,
wherein the binaural rendering unit is further configured to:
receive truncated subband filter coefficients for filtering the input audio signal from the parameterization unit, the truncated subband filter coefficients being at least some of subband filter coefficients obtained from binaural room impulse response (BRIR) filter coefficients for binaural filtering of the input audio signal and the length of the truncated subband filter coefficients being determined based on filter order information obtained by at least partially using reverberation time information extracted from the corresponding subband filter coefficients,
obtain vector information indicating the BRIR filter coefficients corresponding to each channel of the input audio signal, and
filter each subband signal of the multi-channel signal by using the truncated subband filter coefficients corresponding to the relevant channel and subband based on the vector information.
7. The apparatus of claim 6 , wherein when BRIR filter coefficients having positional information matching with positional information of a specific channel of the input audio signal are present in a BRIR filter set, the vector information indicates the relevant BRIR filter coefficients as BRIR filter coefficients corresponding to the specific channel.
8. The apparatus of claim 6 , wherein when BRIR filter coefficients having positional information matching with positional information of a specific channel of the input audio signal are not present in a BRIR filter set, the vector information indicates BRIR filter coefficients having a minimum geometric distance from the positional information of the specific channel as BRIR filter coefficients corresponding to the specific channel.
9. The apparatus of claim 8 , wherein the geometric distance is a value obtained by aggregating an absolute value of an altitude deviation between two positions and an absolute value of an azimuth deviation between the two positions.
10. The apparatus of claim 6 , wherein the length of at least one truncated subband filter coefficients is different from the length of truncated subband filter coefficients of another subband.