[PD] Natty SPDIF samplerate 44.1k / 48k problem (OSS)

András Murányi muranyia at gmail.com
Fri Nov 11 17:13:16 CET 2011

Also, make sure that the Realtek chip does native 44.1...
I feed my MOTU card from the SPDIF output of a Creative Audigy* and I had
to change my workflow to 48k because the Audigy turned out to "fake" 44.1
by constant upsampling/downsampling around its fixed-48k DSP.

* because the FireWire connection is so fragile and the damn MOTU freezes
all the time


On Fri, Nov 11, 2011 at 04:38, Ingo <ingo at miamiwave.com> wrote:

> I think if you are using a mixed patch with osc and samples only the
> samples
> would play correctly and any osc~ might get detuned. Not sure?
> But anyway, as far as I know you can only up or downsample by the power of
> two.
> I did try to use a frequency multiplier of 0.91875 and it was playing in
> tune but that still gave me a samplerate of 48k at the SPDIF out instead of
> the 44.1k which was what I wanted.
> Anyway, I suspect that some instabilities as well as certain losses of
> sound
> quality may happen if the sample rate of Pd conflicts with the sample rate
> of the sound card. This is because of the resampling that the sound card
> needs to do. So getting Pd's sample rate matched up with the rate of the
> hardware might have advantages even if you are using only analogue outs.
> Ingo
> 2011/11/10 Roman Haefeli <reduzent at gmail.com>
> On Thu, 2011-11-10 at 17:14 +0100, tim vets wrote:
> > ..
> > Lastly: I wonder if there isn't a way to downsample some subpatches to
> > playback the 44.1kHz soundfiles in a 48kHz environment?
> Why would you want to run an [osc~ 440] at a different samplerate, when
> it plays a 440Hz anyway?
> Regarding audio samples, you can use [tabread4~] fed by a [line~]
> instead of [tabplay~] for up- or downsampling.
> it was just a thought, I can imagine if you would have based some
> sophisticated sample playback on a whole bunch of tabplay~'s or readsf~'s,
> that maybe you wouldn't want or have time to change all that...
> I checked [switch~] again and indeed you can enter 0.5 to downsample by
> factor 2, does that mean you could enter 0.91875000000000007 to downsample
> from 48 to 44.1?
> Roman
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