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;
receiving a set of truncated subband filter coefficients for each subband and each channel, wherein the set of truncated subband filter coefficients is truncated frequency dependently from a set of subband filter coefficients of a binaural room impulse response (BRIR) data set, wherein the length of the set of truncated subband filter coefficients is determined based on a filter order of the corresponding subband, and wherein the filter order is determined to be variable in the frequency domain;
obtaining vector information indicating a particular BRIR data set corresponding to a relevant channel of the input audio signal; and
filtering each subband signal of the input audio signal by using the set of truncated subband filter coefficients corresponding to the relevant channel and a relevant subband based on the vector information.
2. The method of claim 1 , wherein when a first BRIR data set having positional information matching with positional information of the relevant channel of the input audio signal is present in a predetermined BRIR filter set, the vector information indicates the first BRIR data set as the particular BRIR data set corresponding to the relevant channel.
3. The method of claim 1 , wherein when a first BRIR data set having positional information matching with positional information of the relevant channel of the input audio signal is not present in a predetermined BRIR filter set, the vector information indicates a second BRIR data set having a minimum geometric distance from the positional information of the relevant channel as the particular BRIR data set corresponding to the relevant 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 a length of the set of truncated subband filter coefficients of at least one subband is different from a length of the set 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 binaural rendering unit configured to:
receive an input audio signal,
receive a set of truncated subband filter coefficients for each subband and each channel, wherein the set of truncated subband filter coefficients is truncated frequency dependently from a set of subband filter coefficients of a binaural room impulse response (BRIR) data set, wherein the length of the set of truncated subband filter coefficients is determined based on a filter order of the corresponding subband, and wherein the filter order is determined to be variable in the frequency domain,
obtain vector information indicating a particular BRIR data set corresponding to a relevant 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 a relevant subband based on the vector information.
7. The apparatus of claim 6 , wherein when a first BRIR data set having positional information matching with positional information of the relevant channel of the input audio signal is present in a predetermined BRIR filter set, the vector information indicates the first BRIR data set as the particular BRIR data set corresponding to the relevant channel.
8. The apparatus of claim 6 , wherein when a first BRIR data set having positional information matching with positional information of the relevant channel of the input audio signal is not present in a predetermined BRIR filter set, the vector information indicates a second BRIR data set having a minimum geometric distance from the positional information of the relevant channel as the particular BRIR data set corresponding to the relevant 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 a length of the set of truncated subband filter coefficients of at least one subband is different from a length of the set of truncated subband filter coefficients of another subband.