Method and equipment to generate a signal downmix

A method for generating a downmixed signal (with mixing and reduction channels), comprising: performing (101) one time-frequency transformation on the signal channel left sound signal of a right channel sound to get a signal in the frequency domain, and dividing the signal into the frequency domain in several frequency bands; calculating (103) an energy of the sound channels and a phase difference of the sound channels of each of the frequency bands, wherein the energy ratio of the sound channels reflects information energy ratio signal channel left sound and channel signal right sound in each of the frequency bands, and the phase difference of the sound channels reflects information from the phase difference signal channel left sound and right channel signal sound each of the frequency bands; calculating (105) the phase difference between a downmixed signal and a signal from a first sound channel in each of the frequency bands from the energy ratio of the sound channels and the phase difference channel sound, where the signal from the first sound channel is the left channel signal sound or the right channel signal sound; and calculating (107) a signal downmixed in the frequency domain from the channel signal left sound channel signal right sound and the phase difference between the signal downmixed and the signal of the first channel sound each of the frequency bands; wherein the first audio channel is the channel left sound, and calculating the phase difference between the downmixed signal and the first sound channel in each of the frequency bands from the energy ratio sound channels and the phase difference of the sound channels includes the calculation according to the following formulas: Formula ** ** where CLD (b) is the energy ratio of the sound channels of the b-th frequency band, c (b) is the value of an intermediate variable for calculation, IPD (b) is the phase difference of the sound channels of the besima frequency band and θ (b) is the phase difference between downmixed signal and the signal of the first sound channel in the b-th frequency band; wherein the first sound channel is the channel left sound and calculating the signal downmixed in the frequency domain from the channel signal left sound channel signal right sound and the phase difference between the downmixed signal and the first channel sound in each of the frequency bands includes the calculation according to the following formulas: Formula ** ** where k is the index of frequency point, Lr (k) is the real part of the channel signal left sound in the kth frequency point after time-frequency transformation, Li (k) is the imaginary part of the channel signal left sound in the kth point frequency after time-frequency transformation, Rmag (k) is the signal amplitude of the right channel sound in the kth frequency point after time-frequency transformation, LMAG (k) is the amplitude of the signal left channel sound uierdo in the kth frequency point after time-frequency transformation, My (k) is the real part of the signal downmixed in the frequency domain in the kth frequency point after the time-frequency transformation , Mr (k) is the imaginary part of the signal downmixed in the frequency domain in the kth frequency point after time-frequency transformation, and θ (b) is the phase difference between the downmixed signal and the signal of the first sound channel in the b-th frequency band.