Extraction of a multiple channel time-domain output signal from a multichannel signal

Apparatus for creating a multiple channel time-domain audio signal from a stereo audio signal having a left-input channel digital time-domain signal and a right-input channel digital time-domain signal, the apparatus comprising:

• a memory;
• a time-domain to frequency-domain transform that, responsive to the left-input channel signal, generates at each of a plurality of frequencies, a left-input vector that represents the left-input channel signal and responsive to the right-input channel signal, generates at each of the plurality of frequencies, a right-input vector that represents the right-input channel signal and that stores the left-input vector and the right input vector in the memory;
• a vector resolver that, at each of the plurality of frequencies retrieves a left-input vector and a right-input-vector corresponding to that frequency from the memory and mathematically resolves that left-input vector and that right-input-vector into three derived vectors:
• a derived-left vector, a derived-right vector, and a derived-center vector such that a vector sum of the derived-left vector and one half of the derived-center vector equals the left-input vector, and a vector sum of the derived-right vector and a remaining half of the derived-center vector equals the right-input vector;
• and
• a frequency-domain to time-domain transform that, responsive to the derived-left vectors generates a derived-left output channel time-domain signal, responsive to the derived-right vectors generates a derived-right output channel time-domain signal and responsive to the derived-center vectors generates a derived-center output channel time-domain signal.

Apparatus for creating a multiple channel time-domain audio signal from a stereo audio signal having a left-input channel digital time-domain signal and a right-input channel digital time-domain signal, the apparatus comprising:

• a memory;
• means, responsive to the left-input channel signal, for generating at each of a plurality of frequencies, a left-input vector that represents the left-input channel signal and responsive to the right-input channel signal, generating at each of the plurality of frequencies, a right-input vector that represents the right-input channel signal and storing the left-input vector and the right input vector in the memory;
• means operable at each of the plurality of frequencies, for retrieving a left-input vector and a right-input-vector corresponding to that frequency from the memory and mathematically resolving that left-input vector and that right-input-vector into three derived vectors:
• a derived-left vector, a derived-right vector, and a derived-center vector such that a vector sum of the derived-left vector and one half of the derived-center vector equals the left-input vector, and a vector sum of the derived-right vector and a remaining half of the derived-center vector equals the right-input vector;
• and
• means, responsive to the derived-left vectors for generating a derived-left output channel time-domain signal, and responsive to the derived-right vectors for generating a derived-right output channel time-domain signal and responsive to the derived-center vectors for generating a derived-center output channel time-domain signal.