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, comprising:
receiving an audio signal of a first channel, wherein the first channel is classified into a first channel group, and the audio signal of the first channel includes a plurality of subband signals;
receiving an audio signal of a second channel, wherein the second channel is classified into a second channel group, and the audio signal of the second channel includes a plurality of subband signals;
filtering each subband signal of the first channel by using each set of subband filter coefficients generated from a first set of filter coefficients, wherein the first set of filter coefficients corresponds to a position related to the first channel in a virtual reproduction space;
filtering each subband signal of the second channel by using each set of subband filter coefficients generated from a second set of filter coefficients, wherein the second set of filter coefficients corresponds to a position related to the second channel in the virtual reproduction space; and
generating an output audio signal by mixing the filtered subband signals of the first channel and the filtered subband signals of the second channel;
wherein a length of the set of subband filter coefficients is determined based on a filter order for each subband and for each channel group, and the filter order is variable for each subband and for each channel group.
2. The method of claim 1 , wherein a filter order for a specific subband for the first channel group is higher than a filter order for the specific subband for the second channel group.
3. The method of claim 2 , wherein the first channel group is a front channel group including one or more front channels, and the second channel group is a rear channel group including one or more rear channels.
4. The method of claim 1 , wherein the set of subband filter coefficients is generated by truncating a corresponding set of binaural room impulse response (BRIR) subband filter coefficients, and
the set of BRIR subband filter coefficients is obtained from a set of BRIR filter coefficients in a time domain.
5. The method of claim 4 , wherein a length of the truncation is determined based on a filter order obtained by using characteristic information extracted from the corresponding set of BRIR subband filter coefficients.
6. The method of claim 5 , wherein the characteristic information includes reverberation time information of the corresponding set of BRIR subband filter coefficients.
7. The method of claim 4 , wherein the first set of filter coefficients is a set of BRIR filter coefficients corresponding to the position related to the first channel and the second set of filter coefficients is a set of BRIR filter coefficients corresponding to the position related to the second channel.
8. An apparatus for processing an audio signal, the apparatus is configured to:
receive an audio signal of a first channel, wherein the first channel is classified into a first channel group, and the audio signal of the first channel includes a plurality of subband signals;
receive an audio signal of a second channel, wherein the second channel is classified into a second channel group, and the audio signal of the second channel includes a plurality of subband signals;
filter each subband signal of the first channel by using each set of subband filter coefficients generated from a first set of filter coefficients, wherein the first set of filter coefficients corresponds to a position related to the first channel in a virtual reproduction space;
filter each subband signal of the second channel by using each set of subband filter coefficients generated from a second set of filter coefficients, wherein the second set of filter coefficients corresponds to a position related to the second channel in the virtual reproduction space; and
generate an output audio signal by mixing the filtered subband signals of the first channel and the filtered subband signals of the second channel;
wherein a length of the set of subband filter coefficients is determined based on a filter order for each subband and for each channel group, and the filter order is variable for each subband and for each channel group.
9. The apparatus of claim 8 , wherein a filter order for a specific subband for the first channel group is higher than a filter order for the specific subband for the second channel group.
10. The apparatus of claim 9 , wherein the first channel group is a front channel group including one or more front channels, and the second channel group is a rear channel group including one or more rear channels.
11. The apparatus of claim 8 , wherein the set of subband filter coefficients is generated by truncating a corresponding set of binaural room impulse response (BRIR) subband filter coefficients, and
the set of BRIR subband filter coefficients is obtained from a set of BRIR filter coefficients in a time domain.
12. The apparatus of claim 11 , wherein a length of the truncation is determined based on a filter order obtained by using characteristic information extracted from the corresponding set of BRIR subband filter coefficients.
13. The apparatus of claim 12 , wherein the characteristic information includes reverberation time information of the corresponding set of BRIR subband filter coefficients.
14. The apparatus of claim 11 , wherein the first set of filter coefficients is a set of BRIR filter coefficients corresponding to the position related to the first channel and the second set of filter coefficients is a set of BRIR filter coefficients corresponding to the position related to the second channel.