using 2 computers

[Guenter Geiger]

Michal Seta writes:
 > Hello all,
 > 
 > So, I'm planning to use pd in a performance.
 > The idea was to use 2 laptops running pd under linux.  However, one of the
 > laptops seems to be quite useless as it has no sound input nor output
 > (exept for a built -in mic and speakers...) so I was wondering if using
 > them networked through ethernet would allow me to approximate something of
 > dual processor nature.  Haven't experimented with it as we don't yet have
 > ethernet cards.  I would appreciate any ideas in this repect.  I'm mainly
 > intersted to know what kind and how much data would I be able to exchange
 > between the 2 computers over a (hopefully) 1000baseT ethernet card.

The ethernet is definitely fast enough to transmit a few channels of
audio data. As I'm planning to do some experiments with pd on the 
network I started writing an external which streams audio data over
the internet.

available at <http://wonk.epy.co.at/pdlib/externals/stream.tar.gz>

Streaming over the ethernet will lead to a certain delay and is only
reliable if you know the traffic that is generated (by others).

 > 
 > Also, relating to the running of pd under root.  I've tried to run it as a
 > user and it works fine except for clickes (and obviously I'm not the only
 > one that has noticed it) and I've noticed the same type of clicks when I
 > use MixViews to play large soundfiles.  Running audio software as root
 > doesn't seem to have the same side-effect.  How can I optimize it?
 > 

Hmm, .. the code for switching on high priority scheduling has to be in the
executable. So you'd have to change the source of mixviews and
recompile if you want to get the same effect.
You can experiment with "nice" to change the scheduling somehow. 

 > Obviously, I still don't understand the concept behind running pd (or
 > other software) under root vs. user...
 > 

This is just, that a normal user never has the right to change the 
scheduling in the manner as pd does. This is good, because it can be 
very dangerous.

Guenter

 > thnkx
 > 
 > .....                            ....
 >      ......   Michal Seta  ......
 > .....                            ....
 > 
 >