[PD] is bang~ limited to a 64 sample block?

Martin Schied crinimal at gmx.net
Sat Jun 20 16:34:15 CEST 2009


Actually I have no precise knowledge of dsp scheduling and such things, 
I only had this 64-sampes "problem" once but found other solutions to 
solve it. From my (current) point of view it's not a good method to 
reduce scheduling times too much on a desktop cpu, because of overhead 
becoming more and more significant - but maybe I'm totally wrong here 
and there are scheduling mechanisms without those  side effects.

When I had this issue I had an idea to work out a "virtual" sample 
accurate timing mechanism on patch level which has additional 64 samples 
delay but gives you possibility to describe your problem as "sample based".

for example a threshold~ with sample accurate output can be achieved by 
using tabsend~ and tab_ge from iemtab. But that was not thought very far.

maybe I'll think about it when I have more time...

btw. what for did you need these high-accuracy timings? would be 
interesting to gather some of those timing problems and look for a 
common solution...


brandon zeeb wrote:
> Any chance of having the ability to change that globally if need be?
> On Fri, Jun 19, 2009 at 8:30 PM, Martin Schied <crinimal at gmx.net 
> <mailto:crinimal at gmx.net>> wrote:
>     hi!
>     hard off wrote:
>         I made a patch which times the duration between two bangs sent
>         by [bang~].   If i set the blocksize to the default of 64,
>         then each bang comes 1.4ms apart - as expected with 44.1khz
>         samplerate.
>         However, making the blocksize smaller has no effect on the
>         duration between the bangs.
>         Does bang~ have a speedlimit of 64 samples?  If not, what is
>         the limiting factor stopping me getting bangs more often than
>         every 1.4ms?
>     it's a 64 samples limit as far as i read in archives some time ago...
>     http://lists.puredata.info/pipermail/pd-list/2002-04/006123.html
>     Martin
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