[PD] questions

Orm Finnendahl finnendahl at folkwang-hochschule.de
Fri Jan 4 13:02:16 CET 2002

Am Donnerstag, den 03. Januar 2002 um 17:22:33 Uhr (+0100) schrieb Krzysztof Czaja:
> > Is it possible to run realtime synthesis with csound in pd? (like it is
> > possible now with max)
> Not yet (but soon...?)

For linux there exists a solution:

Over the holidays, I wrote an external for pd, which is similar to the
print object, but enabling the output of arbitrary symbols or floats
to a file rather than to the message window. Csound for linux has an
option to take realtime scorefile input from a pipe. Thus you can
create a pipe as pseudo file with the command "mkfifo <filename>",
specify this filename as pipe input in csound (using the -L flag) and
open this file for writing from within pd (using my fileprint

That way, any i-statements or f-statements are interpreted as if they
were written in the scorefile. The only difference is that p2 is
interpreted as time-offset from the time of arrival at the pipe (which
actually is quite handy).

In order to control csound at k-time, there is an OSC port in the
unofficial version of csound for linux.

The only problem which remains is to redirect the sound output of
csound back to pd. (Since csound blocks the audio-ports, you can't do
any signal processing in pd if you don't have multiple soundcards.)
Maybe someone has an idea, how to get that done. But I guess this
issue has to be attacked from within csound.

the pd object, I wrote, is very small (ca. 6 KB) and I could well
imagine its functionality can somehow be obtained with standard
pd-objects. But if anybody is interested in it, drop me a note.

The object has one drawback, though: pd strips the first element in a
list which is sent to the object, as I used class_addanything in the
setup function of the object. There must be a way to get around that,
but unfortunately, programming pd-externals is not very well
documented and I remember back from the days when I wrote MAX
externals that it is a little tricky. If anybody can help me with that
it would be great since it doesn't make a lot of sense to send

"foo i1 0 0.3 72 60.3" 

when all you want to get printed is 

"i1 0 0.3 72 60.3".

Also, extensive error checking isn't implemented.


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