[PD] netsending pixes

IOhannes m zmoelnig zmoelnig at iem.at
Fri Apr 11 12:09:35 CEST 2008

Raphaël ILIAS wrote:
> hi list !
> i'm working on live-captured video treatment with gem. the main patch is 
> okay, but in order to get a convenient improvisation tool, i would like 
> to have a "control monitor" with another content that what's dsiplayed 
> on the main gemwin (which is shown to the audience)...
> captured frames are stored in a pix_buffer (360x288px on 1 channel - 
> grey) and i thought to send them to another computer with its own gemwin 
> in which they might be displayed (for the performer)...
> i tried with on one side, [pix_dump] and [netsend] and, on the other 
> computer, [netreceive] and [pix_set]...
> it was very slow, and crashed... so, i reduced the picture to 45x36 px 
> and split the pix-list into packets of 100 floats. i finally got a 
> picture, but lines aren't synchronized (i get "diagonals"), and i don't 
> understand why...
> does someone see an easier solution to pass pixes through a local 
> network ? i don't care a lot about latency (hem...less than 10 seconds 
> of course) and resolution...

on osx and linux you can use [pix_share_read] and [pix_share_write] to 
share images between two instances of Pd/Gem on one(!) computer via 
shared-memory. this should be very fast.

afair, there are some freeframe-plugins that allow you to send images 
from one host to another (via network), but i don't know on which 
platform they are available (i guess: w32) and whether they are free; i 
never tried them, but they should be usable with [pix_freeframe].

depending on what you are doing, it might be easiest to just run 2 
(synched) instances of Gem that independently produce the 2 visuals (and 
are controlled by a single patch)

or use a multi-monitor setup and do clever things to get 2 virtual 
monitors in a single gemwindow.

or pay the developers a lot of money to finally get the multi-window 
support into Gem which i have been promising for more than 3 years :-)


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