We operate on a complex cepstrum (size is the number of complex frames). We distinguish
a left L (causal) and right R (anti-causal) half. The formulas then are
reL_out = crr * reL + ccr * reR
reR_out = clr * reR + car * reL
imL_out = cri * imL + cci * imR
imR_out = cli * imR + cai * imL
Note that causal and anti-causal are misnamed in the coefficient.
For example, to make the signal causal for minimum phase reconstruction: We add the conjugate anti-causal
(right) part to the causal (left) part:
crr = 1, ccr = 1, cri = 1, cci = -1
and clear the anti-causal (right) part:
clr = 0, car = 0, cli = 0, cai = 0
(you can just call FoldCepstrum.minPhase for this case)
- Companion:
- object