As has been mentioned here in the past, I have been tinkering with quartz composer for use as dynamic, digital signage. It is a good fit: extremely fast, can talk to the internet, usable on a lot of different systems. There are a growing number of locations within the museum where we’d like to apply dynamic signage, but off the shelf systems to do it are often convoluted and proprietary, not to mention expensive. Currently in the Walker Cinema, we use a DVD that I render in After Effects and update periodically. This affords a lot of control, but also takes a fair amount of labor to update.
It is this kind of an application where Quartz Composer can work well. Any quartz composer movie can be saved as a quicktime movie, but there are some limitations:
- no mouse and keyboard events
- no contents download from Internet (RSS feeds, images…)
- edition of the input parameters of the compositions
Notice that second one? That’s the doozy if you want your quartz comp quicktime movie to use an RSS feed to get the text.
There is a simple workaround, though, and that is to simply download the RSS feed to the local machine before you open the movie in quickitime. You simply build the composition (before saving it as a movie) to look for that file on the local drive. Here’s a quick command to grab our RSS feed and save it:
/usr/bin/curl http://calendar.walkerart.org/news/today.wac > /tmp/today.html
And then your path for the RSS feed inside quartz is:
file://localhost/tmp/today.html
Problem one solved. This lets us manually open up the quicktime movie and export it to any format quicktime can export to. Once you have it in that format, you can transform it, play it or transfer it with much more ease.
I’ll post about how to automate the whole process in the future, and the problems that occur when you try to deal with HD resolution screens. In the meantime, here is a short demo of what I have been able to achieve with quartz composer and our identity system (a work in progress).

For some automation tasks, you might want to have a look at qtzplayer by Joćo Pavćo:
http://trac.softwarelivre.sapo.pt/broker/wiki/qtzplayer“>
“This is .qtz player for OSX that will work from the shell command line. It’s useful for kiosk scripts, scripting in general or just to start a presentation from a SSH session.”
This might be useful in finding a workaround for your RSS feeds issue, though grabbing RSS from a locally cached file might be a mixed blessing.
Comment by Paul Wenzel — 1/30/2007 @ 10:09 am
Sorry, I messed up the link in my above comment. It should be:
http://trac.softwarelivre.sapo.pt/broker/wiki/qtzplayer
Comment by Paul Wenzel — 1/30/2007 @ 10:10 am
We’ve got a single installation (2 screen) digital signage solution running using Quartz Composer as a screen saver that successfully pulls data from an RSS feed for content. We use a WordPress weblog as the source, which allows multiple authors to post news, which shows up on the display as soon as the feed is refreshed (every 30 minutes).
Comment by Dale Pike — 4/19/2007 @ 4:28 pm
[…] played with before. I also made a version of a screensaver that uses more of Walker Expanded, and posted about it a few months back. In depoloying it to the iMacs, though, I ran into some trouble. The machines we’re using […]
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