Re: [Csnd-dev] [EXTERNAL] [Csnd-dev] UDO local sr

Ah, it was just arrays that were limited. Great!

I'll be sure to install libsamplerate and will see what I can do with
regards to testing

Readers,
ANders

On Wed, Mar 20, 2024 at 2:10 PM Victor Lazzarini <[email protected]>
wrote:

> Make sure you have libsamplerate for the best quality conversion. There’s
> a simple fallback converter, but Secret Rabbit Code is better.
>
> The limitations are:
>
> - can’t setksmps alongside it
> - can’t use a-rate or k-rate arrays (that may be possibly changed in the
> future).
> - if you use global arrays or bus channels it won’t work either. All
> access has to be
> through xin and xout, because that’s where the conversion happens.
>
> Testing is helpful, thanks for that.
> ========================
> Prof. Victor Lazzarini
> Maynooth University
> Ireland
>
> > On 20 Mar 2024, at 11:27, Anders Genell <[email protected]> wrote:
> >
> > Ah, brilliant!
> > I just saw the flurry of emails connected to the code submissions and it
> said something about not allowing a-rate, but that was likely a
> misinterpretation of mine.
> >
> > I will try to build and test to see if my scenario seems to work as I
> hope.
> >
> > Thank you!
> >
> > Regards,
> > Anders
> >
> >
> > On Wed, Mar 20, 2024 at 10:51 AM Victor Lazzarini <
> [email protected]> wrote:
> > Hi Anders,
> >
> > There is now an undersample opcode to go along with the oversample. I am
> not sure what you mean about 2., it does allow
> > a-rate opcodes.
> >
> > best
> > ========================
> > Prof. Victor Lazzarini
> > Maynooth University
> > Ireland
> >
> > > On 20 Mar 2024, at 08:55, Anders Genell <[email protected]>
> wrote:
> > >
> > > *Warning*
> > > This email originated from outside of Maynooth University's Mail
> System. Do not reply, click links or open attachments unless you recognise
> the sender and know the content is safe.
> > > This is mainly for Victor Lazzarini,
> > >
> > > I saw you added code in a PR to implement local sample rate in UDOs
> which I think is absolutely fantastic.
> > > It seems there are two limitations that I really hope could be
> addressed in the future:
> > > 1. The code allows for upsampling but not for downsampling
> > > 2. The code does not allow for a-rate opcodes
> > >
> > > The use case I am hoping will be possible in the future is when having
> a reasonably high global sr (say 48kHz or even 96kHz) where I would like to
> apply relatively narrow band filters with center frequencies at say 20Hz,
> 25Hz 32Hz or the like. Such filters tend to be somewhat unstable at such
> high SR if they also need to be reasonably steep, and by downsampling
> before filtering a better result is often achieved. This is commonly done
> in signal processing for analysis in e.g. Matlab or GNU octave.
> > > The idea is e.g. to be able to manipulate individual bands, like in
> the pvs group of opcodes, and combining the individual bands back to one
> signal afterwords, so just docking global reduction of SR would not be a
> viable route, unless of course starting several instances of csound and
> using channel opcodes to combine everything in the end.
> > >
> > > Would this be a possibility in some future iteration of the newly
> implemented code?
> > >
> > > Regards,
> > > Anders
>
>