[PD] grain patch producing clicks

Alexandre Matheson amatheso at alcor.concordia.ca
Thu May 25 02:16:31 CEST 2006


hello dafydd, Frank, and list,

Thanks for the feedback. I will start making improvements on the  
patch as soon as i get over this cold.

On 23-May-06, at 1:09 PM, Frank Barknecht wrote:

> Hallo,
> dafydd hughes hat gesagt: // dafydd hughes wrote:
>
>> It looks like a mismatch between envelope and sample reading.  The
>> clicks seem to happen because the amplitude envelope and the  
>> tabread4~
>> aren't synchronized.  What happens is the tabread object gets its new
>> starting position while the envelope is still in mid-grain.  The
>> solution is to make sure each voice is inactive before starting a new
>> grain.
>>
>> David Golightly made a great granular delay line patch (I think based
>> on a paper by Ross Bencina) maybe a year and a bit ago which used a
>> scheduler to send info to each voice.  As I remember, the scheduler
>> kept track of which voices were playing and sent the messages to the
>> next available note.  Another way is to let the voice pass the  
>> message
>> to the next voice if it's already busy.
>
> I changed the patch to do just that and introduced an abstraction for
> the voices, because I'm lazy. The blocking is in [pd block] in
> pd_voice.pd. However while this gets rid of the clicks, it brings
> another problem with the patch to daylight, which you will immediatly
> hear, if you try it: it doesn't sound like a cloud of grains, but very
> regular. I didn't understand what the [expr $f1; $f1/1; $f1/2 ...] is
> supposed to do. In the original patch, the numbers get send to a [del]
> object where they get translated to a simple bang.
>
> I once did another granular patch that uses a [phasor~] instead of a
> [metro] to drive the grains. Basically the phasor~ output is used to
> drive a cosine envelope similar to the packets example in Miller's
> docs. It also is used to read out the table with [tabread4~] or a
> delay line with [vd~]. [samphold~]'s are used to get click-free
> operation. I attached this patch as well (phasorgrain~). It normally
> uses Memento to allow comfortable remote control of the settings, but
> I ripped this part out to not confuse those without Memento.
>
> Ciao
> -- 
>  Frank Barknecht                 _ ______footils.org_ __goto10.org__
> <help-sk-lens.pd>
> <sk-lens.pd>
> <pd_voice.pd>
> <phasorgrain~.pd>
> <phasorgrain~-help.pd>
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