[PD] accuracy of signal/message-objects

marius schebella marius.schebella at gmail.com
Tue May 8 15:13:15 CEST 2007

Steffen wrote:
> On 08/05/2007, at 9.19, IOhannes m zmoelnig wrote:
>> because they do not interface with the world outside.
> I feel that i don't interface with "the world" inside. I would  
> greatly appreciate if someone would translate the scope of this  
> discussion into noobish.

think of it as Pd being a tool also used for non realtime renderings. in 
fact it is possible that Pd renders everything to a soundfile and not to 
the sound card.
so if you have very complicated computation which cannot be done in real 
time because the cpu is not fast enough, that data would still be 
written to the soundfile without clicks. and that is because pd has its 
internal predictable time. if you want to trigger a message with 1000 
milliseconds delay then you want to use the internal time measurement. 
for example if you load a 2 hours soundfile into a buffer in the first 
millisecond and start playing it that usually would cause Pd to clip and 
that is because it takes a while until the sound file is written to the 
buffer. Pd cannot continue with its internal measurement until all 
messages are finished executing. that is an example where internal time 
and world time would drift.
the internal time is cut into pieces of 64 samples (at 44.1 khz sampling 
rate that is 1.6 ms). then the samples are sent to the soundcard 
(clocked by the soundcard) and then the next rendercycle of 64 samples 

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