> On March 11, 2020 6:53 PM Ethan Duni <ethan.d...@gmail.com> wrote:
>
>
> On Tue, Mar 10, 2020 at 8:36 AM Spencer Russell <s...@media.mit.edu> wrote:
> >
> > The point I'm making here is that overlap-add fast FIR is a special case
> > of STFT-domain multiplication and resynthesis. I'm defining the standard
> > STFT pipeline here as:
> >
> > 1. slice your signal into frames
> > 2. pointwise-multiply an analysis window by each frame
> > 3. perform `rfft` on each frame to give the STFT domain representation
> > 4. modify the STFT representation
> > 5. perform `irfft` on each frame
> > 6. pointwise-multiply a synthesis window on each frame
> > 7. overlap-add each frame to get the resulting time-domain signal
>
> I don't think there is a precise definition of STFT, but IMO this is too
> generic.
i don't think it's too generic for "STFT processing". step #4 is pretty
generic.
here is my attempt to quantitatively define and describe the STFT:
https://dsp.stackexchange.com/questions/45625/is-windowed-fourier-transform-a-synonym-for-stft/45631#45631
> The fundamental design parameters for an STFT system are the window shapes
> and overlaps, but in fast convolution those degrees of freedom are eliminated
> entirely.
>
in most cases. and while it's not as "fast", you *can* do overlap-add fast
convolution with a Hann window (instead of rectangular) and have a frame hop of
about 1/2 as the regular old overlap-add fast convolution. it's only half as
efficient, but i would still call it "fast convolution" and it is also a subset
of STFT processing. this is the "small intersection" of the Venn diagrams
between the two that i meant earlier.
> The reason this distinction is important is that STFT is for cases where you
> want to estimate the response in the frequency domain. If you can't apply a
> useful analysis window, then there isn't much point.
>
i think i agree with this, too.
--
r b-j r...@audioimagination.com
"Imagination is more important than knowledge."
_______________________________________________
dupswapdrop: music-dsp mailing list
music-dsp@music.columbia.edu
https://lists.columbia.edu/mailman/listinfo/music-dsp
