Patent ID: 8363855
Filing Date: 2013-01-29
Classification: H04S

Abstract:
1. A method of determining mix coefficients for downmixing a multichannel input signal, having a right input channel, a left input channel and a center input channel to an output signal having a right output channel and a left output channel, comprising: receiving a multichannel input signal at signal inputs corresponding to each input channel; bandwidth limit filtering each input channel of the multichannel input signal with a controller coupled to the signal inputs to obtain bandwidth limited input channel information for each input channel; determining a bandwidth limited input channel energy for each of the right input channel and the left input channel using the bandwidth limited input channel information for each of the right, left and center input channels; determining a bandwidth limited output channel energy for the right output channel and the left output channel using the bandwidth limited input channel information for each of the right, left and center input channels and at least one of a plurality of test mix coefficients having a current value; determining an updated value for the at least one of the plurality of test mix coefficients based on a comparison between the bandwidth limited input channel energy of one of either the left input channel or the right input channel with the bandwidth limited output channel energy of the corresponding one of either the left output channel or right output channel; updating a corresponding at least one of a plurality of full bandwidth mix coefficients using the updated value of the at least one of the plurality of test mix coefficients; and mixing, with the controller, the multichannel input signal to obtain the output signal using the full bandwidth mix coefficients.