rbj wrote:
>1. resampling is LTI **if**, for the TI portion, one appropriately scales
time.
Have we established that this holds for non-ideal resampling? It doesn't
seem like it does, in general.
If not, then the phrase "resampling is LTI" - without some kind of "ideal"
qualifier - seems
> The fact that 5,17,-12,2 at sample rate 1X and
> 5,0,0,0,17,0,0,0,-12,0,0,0,2,0,0,0 at sample rate 4X are identical is obvious
> only for samples representing impulses.
>
> I agree that the zero-stuff-then-lowpass technique is much more obvious when
> we you consider the impulse train
OTOH, just about everything we do with digital audio doesn’t exactly work.
Start with sampling. Do we give up if we can’t ensure absolutely no signal at
and above half the sample rate? Fortunately, our ears have limitations (whew!).
;-) Anyway, the aliasing occurred to me as I wrote that, but
�
okay, i can't resist jumping back in here.
i have O but i don't have O although i once taught an elective class of
audio and signal processing in which we used O as a text (but i was using the
department copy).
i've always considered the "canonical EE approach to the subject" is
>
> First, I want to be clear that I don’t think people are crippled by
> certain viewpoint—I’ve said this elsewhere before, maybe not it this thread
> or the article so much.
In that case I'd suggest some more editing is in order, since the article
stated this pretty overtly at least a couple
>
> Time variance is a bit subtle in the multi-rate context. For integer
> downsampling, as you point out, it might make more sense to replace the
> classic n-shift-in/n-shift-out definition of time invariance with one that
> works in terms of the common real time represented by the different
>
