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 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 being classified into a first subband group having only low-frequency subband signals determined based on a predetermined frequency band and a second subband group having only high-frequency subband signals determined based on the predetermined frequency band;
performing, by a fast convolution unit, fast convolution on each low-frequency subband signal of the first subband group;
receiving, by a tap-delay line processing unit, at least one parameter corresponding to each high-frequency 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 high-frequency subband signal of the second subband group; and
performing, by the tap-delay line processing unit, one-tap-delay line filtering of each high-frequency subband signal of the second subband group by using the received parameter.
2. The method of claim 1 , wherein the parameter includes one delay information for the corresponding BRIR subband filter coefficients and one gain information corresponding to the delay information.
3. The method of claim 2 , wherein the delay information indicates positional information for a maximum peak in the BRIR subband filter coefficients.
4. The method of claim 2 , wherein the delay information has a sample based integer value in a QMF domain.
5. The method of claim 2 , wherein the gain information has a complex value.
6. The method of claim 1 , further comprising:
summing the filtered high-frequency subband signals to 2-channel left and right subband signals for each subband;
coupling the summed left and right subband signals with left and right subband signals generated from the low-frequency subband signals of the first subband group; and
QMF-synthesizing the respective coupled left and right subband signals.
7. An apparatus for processing an audio signal, which is used for performing binaural rendering for 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 first subband group having only low-frequency subband signals determined based on a predetermined frequency band and a second subband group having only high-frequency subband signals based on the predetermined frequency band, the apparatus comprising:
a fast convolution unit configured to perform fast convolution on each low-frequency subband signal of the first subband group; and
a tap-delay line processing unit configured to perform rendering of each high-frequency subband signal of the second subband group,
wherein the tap-delay line processing unit receives at least one parameter corresponding to each high-frequency 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 high-frequency subband signal of the second subband group, and
performs one-tap-delay line filtering of each high-frequency subband signal of the second subband group by using the received parameter.
8. The apparatus of claim 7 , wherein the parameter includes one delay information for the corresponding BRIR subband filter coefficients and one gain information corresponding to the delay information.
9. The apparatus of claim 8 , wherein the delay information indicates positional information for a maximum peak in the BRIR subband filter coefficients.
10. The apparatus of claim 8 , wherein the delay information has a sample based integer value in a QMF domain.
11. The apparatus of claim 8 , wherein the gain information has a complex value.
12. The apparatus of claim 7 , wherein the tap-delay line processing unit sums the filtered high-frequency subband signals to 2-channel left and right subband signals for each subband, and
the apparatus for processing an audio signal further includes:
a mixer configured to couple the summed left and right subband signals with left and right subband signals generated from the low-frequency subband signals of the first subband group; and
a QMF synthesis unit configured to QMF-synthesize the respective coupled left and right subband signals.