I'm confused because of filter length, whether (such) filters can be used to filter audio on a "per sample basis"?
By per sample basis I mean that I would like to filter audio one sample at a time, but vary the filter parameters even one sample at a time.
What then confuses me is, can the filter have any effect if only one sample is input to it? Or whether the filter needs a longer sample (e.g. that matches the filter length)?
Since the filter type seems crucial, I'm specifically interested in the Parks-Mccellan FIR and the context is dynamic equalization (in which it seems like the parameters such as gain would need to be varied on a close to per sample basis). I.e. I'm interested in whether the PM algorithm can be utilized for dynamic equalization in such way that one recomputes the PM between some samples and then filters those samples, i.e. in a block-like fashion.