[PD] Maybe I'm pushing dynamic object creation too far

[Ed Kelly]

> On 2011-02-02 01:00, Ed Kelly wrote:

> > I get dropouts, regardless of the jack buffer size/buffers number. Is this 
> > because the dynamic creation of a new object interrupts the pd audio stream? 
>If 
>
> > so, can this be alleviated - 1. is it a GUI problem (and will pd 0.43 fix it) 
>
> > and 2. if so, can pd -nogui sort it out?

> the problem most likely comes from the DSP graph being continuously rebuilt.
> the only things you can do for now is:
> - - try to reduce rebuilding of the DSP graph as much as possible.
> needeless to say that you shouldn't dynamically create objects that are
> not needed.
> more interesting is that e.g. creating 3 objects while audio is running,
> will re-caculate the DSP graph 3 times. even if this happens in 0
> logical time. so i you know you are going to schedule several
> dynamically created objects "at once", turn audio off before and turn it
> on again after you do the actual creation.

Dammit!
Only one at a time, but they are tables of perhaps 300000 points. Then I copy 
data from the input buffer into the table.
It has to be running with the audio, since the audio is being re-mixed in real 
time.
Everything works fine if I'm using the onboard sound - e.g. OSS, but the 
problems only happen when I switch to jack. Of course the onboard sound would be 
OK if I was using only output, but the whole point is to live-sample the input. 
The mic input on my laptop is really crappy.

> - - try to get the DSP graph building into a separate thread.
> well, this involves pd~ or the like....

Dammit again - I'm using the second core of the machine for the live score, 
dynamic object creation in GEM
 - but I see the new version of Inscore supports PD, so all my work over the 
last 6 months has been for nothing.
Pah!

Ed


fgmasdr
IOhannes





[1] btw, it's usually really easy to check things: e.g. running your
patch with "-nogui" and see whether you get dropouts might take about
the same time as (you) asking on this list, (me) answering on this list
and (you) reading the answer - not counting the delay due to
amil-servers and the like. anyhow.
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