A DSP loop is when signal connections form a loop. Pd can't look into
objects so it just treats them as black boxes. It's as simple as that.
After all, in your example with the effect outside your abstraction you
can literally *see* the DSP loop, why are you surprised? And in your
other example with the effect inside your abstraction you don't get a
DSP loop because, well, there's is no DSP loop.
I see where you're coming from. In the analog world your two examples
are indeed equivalent, but in Pd they are *not*.
Christof
On 25.02.2020 23:46, Christof Ressi wrote:
especially because of additional potential delay of inlet~/outlet~.
inlet~/outlet~ does *not* add a delay (unless when going to a larger
blocksize).
But you're using [r~] and [s~] which is not the same as direct
signal connections. The former can act like a short delay line.
Please read "3.audio.examples/G05.execution.order".
Christof, Yes! Exactly!
I think you misunderstood. With "former" I meant [r~]/[s~].
[inlet~]/[outlet~] does not add a delay.
Also, believe me, r~/s~ has nothing to do with it.
Believe me, it certainly has. Can you finally share a minimal test
patch, please? I would like to see an actual patch where you get an
unexpected DSP loop error.
Christof
On 25.02.2020 23:40, William Huston wrote:
On Tue, Feb 25, 2020 at 6:14 AM Christof Ressi
<i...@christofressi.com <mailto:i...@christofressi.com>> wrote:
@Dan
As far as I recall, going between abstraction to parent patch
via inlet~/outlet~ introduces a block delay, hence no error
Dan, correction-- that is the exact circumstance where I *am* getting
the error.
So now I think you are beginning to see why I think it's unexpected,
especially because of additional potential delay of inlet~/outlet~.
Dan also wrote:
> As the error says, you shouldn't create a direct feedback loop with
signal cords.
Let me try to explain again:
*I have taken a WORKING CIRCUIT--*
**
(a simple stereo delay circuit, with cris-cross L/R feedback
implemented with [delwrite~] + [vd~])
*-- which DOES NOT produce a "DSP Loop Error",
*
*pulled a Null (straight-wire) Filter
*
*(which had been installed in the feedback path)
*
*and moved it externally to the abstraction*
*(up to the parent patch), via outlet~/inlet~,*
*which, if anything ADDS additional block delays,
*
*yet this produces "DSP Loop Error".
*
*
*
*Clearly (the way I see it)
*
*the logic behind detecting "DSP Loop Error" condition
*
*has a bug.*
*I believe this is a false error,*
*because as I have stated--*
*the circuit HAD been working!*
*
*
*All I did was add the potential for additional*
*blocks of delay on the feedback path.
*
But you're using [r~] and [s~] which is not the same as direct
signal connections. The former can act like a short delay line.
Please read "3.audio.examples/G05.execution.order".
Christof, Yes! Exactly!
Added delay should REDUCE the chance of a "DSP Loop Detected"!
Also, believe me, r~/s~ has nothing to do with it.
My original patch was extremely ugly, due to criss-crossed feedback.
I only implemented with r~/s~ to clean up the patch to share.
Thanks everyone!
BH
Christof
On 25.02.2020 11:42, Dan Wilcox wrote:
As far as I recall, going between abstraction to parent patch
via inlet~/outlet~ introduces a block delay, hence no error
Third patch is like the second, only the effect has been moved
out of the abstraction, and into the parent patch. ONLY HERE do
I get the DSP loop error.
Signal loop in a single patch without abstractions = error. Pd
has no way to read and write to the same signal buffer in the
patch at the same time *without* some tiny delay.
*The point is the last two patches have (or should have) an
identical graph! *
At the lower level, they don't. What happens if you put part of
the path inside a subpath which uses inlet~/outlet~?
On Feb 25, 2020, at 11:36 AM, William Huston
<williamahus...@gmail.com <mailto:williamahus...@gmail.com>> wrote:
First abstraction, simple stereo delay: 2 delay lines,
variable feedback L->R, R->L.
This *works*, no DSP loop error.
Second abstraction contains an effect in the feedback path. (in
my simple example, it's just a null wire: In-L passes to Out-L,
etc). Again this *works*, no DSP error.
Third patch is like the second, only the effect has been moved
out of the abstraction, and into the parent patch. ONLY HERE do
I get the DSP loop error.
*The point is the last two patches have (or should have) an
identical graph! *
*
*
It really seems like a bug to me.
I'll upload a test patch a little later.
Thanks,
BH
--------
Dan Wilcox
@danomatika <http://twitter.com/danomatika>
danomatika.com <http://danomatika.com>
robotcowboy.com <http://robotcowboy.com>
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