OLA Summary, Cont'd

Stated as a procedure, we have

(1)

Extract the $m$ th frame of data at time $mR$ .

(2)

Shift it to the base time interval $[0,M-1]$ (or $[-(M-1)/2,(M-1)/2]$ ).

(3)

Apply the analysis window $w$ (causal or zero centered, as preferred).

(4)

Zero-pad the windowed data out to the FFT size (a power of 2).

(5)

Take the $N$ -point FFT.

(6)

Apply the filter $H$ as a windowing operation in the frequency domain.

(7)

Take the $N$ -point inverse FFT.

(8)

Shift the origin of the $N$ -point result out to sample $mR$ where it belongs.

(9)

Sum into the output buffer containing the results from prior frames (OLA step).