Patent ID: 9338573
Filing Date: 2016-05-10
CPC Classification: H04R,H04S

Claim Text:
1. A method performed by one or more processing devices for upmixing a two-channel input audio signal having a first input channel and a second input channel into an upmixed multi-channel output audio signal having greater than two channels, comprising: calculating a first dematrixing coefficient, denoted as a, and a second dematrixing coefficient, denoted as b, based on an inter-channel level difference, denoted as ICLD, and an inter-channel phase difference between the first and second input channels, denoted as ICPD, wherein the first dematrixing coefficient is a combination of an in-phase signal component and an out-of-phase signal component; calculating an estimated panning angle from the inter-channel level difference; calculating an in-phase coefficient and an out-of-phase coefficient based on the estimated panning angle, wherein the in-phase signal component is based on the inter-channel phase difference multiplied by the in-phase coefficient and the out-of-phase signal component is based on the inter-channel phase difference multiplied by the out-of-phase coefficient; multiplying the first input channel by the first dematrixing coefficient to generate a first sub-signal and the second input channel by the second dematrixing coefficient to generate a second sub-signal; mixing the first sub-signal and the second sub-signal in a linear manner to generate an output channel of the upmixed multi-channel output audio signal; and outputting the generated output channel for playback through speakers.