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Ars Electronica Festival 2012

Last week I attended Ars Electronica Festival with an additional title “The Big Picture”. This was quite a new experience for me, because I usually visit technical conferences, while this one was more about art (but tech was of course present as well!).

The first evening in Linz I decided to spend with folks from hackerspace Linz called DevLoL. Technically, it’s not a hackerspace yet, because they are still waiting for their premises, but once they get them, it’s gonna be great! They are promised around 1000 square meters of space in a former tobacco factory, now a culture centrum called Tabakfabrik. Hopefully they’ll be able to do some amazing projects there soon. We had a great discussion about stuff we do at brmlab and I got some valuable input as well. It’s always nice to see more and more hackerspaces to appear in new places.

The other days were mostly about Ars Electronica. I attended quite a lot of expositions, talks and events. If you’ve never been to Ars Electronica Center, go there, their main exposition is amazing and the tickets are quite cheap (8 EUR full price).

During the festival these two projects caught my eye: CogniToo and BioBookCover. The first one is basically a tattoo of your fMRI scan. The times when people were tattoing the names of their loved ones are past, the future is having a fMRI scan of your brain while thinking about your love. :-) The second one is an attempt to create biodegradable (starch based) plastic, which can be made in amateur environment (like a kitchen) and will dissolve in few days (in contrast to few centuries) in nature if thrown away.

From the talks I mostly enjoyed the talk from Golan Levin. He started with the following image:


I think it’s really a good way how to describe current efforts in technology. He didn’t said that explicitly, but my opinion is that artists are leaning towards interesting-beautiful side and hackers towards useful-interesting side of things. There are also other groups like for example designers, which are positioned somewhere else in the triangle. Golan showed us some examples of interesting-beautiful projects like: Most Wanted and Least Wanted Paintings by Komar Melamid, Every Playboy Centerfold by Jason Salavon or The Secret Lives of Numbers by himself.

Other nice talks I attended were about about Free Universal Construction Kit and Apertus, an open source camera. It’s nice to see that an idea of open-source hardware is advancing in these more-or-less artistic fields as well.

But undoubtedly, the main attraction of the festival were so called Klangwolke (Sound clouds). This is a tradition that happens on the bank of Danube river every year and this time there were around 90000 participating people. Around one thousand of them used an opportunity to make a big blinking letter during the festival and these were connected via network during the performance. The letters were not the only things blinking, we also had a chance to see buildings with projections and 50 quadcopters flying changing colour and flying in nice formations. See the video for yourself:

I’d like to thank all people I hanged out with (especially Prokop who made the trip possible and Szara who kindly sheltered me) and I hope I’ll be able to visit the event next year as well!

Convert PyQt4 Applications to PySide


I just noticed (little bit late, but better later than never :-)) that PySide has become an official part of the Qt Project.

Thus I decided to rewrite all my PyQt4 applications to PySide. There are couple of options how to make your code to work with both PyQt4 and PySide, but in my opinion this adds a lot of cruft to the source code and there’s no reason to stay with PyQt4 so most of the systems will migrate to PySide in the near future. If you want to learn about these options anyway, consult the Supporting Both APIs section of the Differences Between PySide and PyQt at Qt wiki.

This document has also been a very helpful source of information for my simple script that converts your code from PyQt4 API to PySide. Please note that it’s not a 100% fully automated conversion, just a bunch of simple replacements and a scanner for problematic API usage like using QString, QVariant or the return value of QFileDialog methods. I am releasing it because I still do think it’s quite helpful and covers most of the cases.

Grab the source on github and of course you are welcome to send your patches/pull requests. :-)

Timelapse video with webcam and mplayer

Some time ago I created a timelapse video using webcam and mplayer:

Today I was asked how I did it and because I did not remember exactly the command line options I decided to write this post to save you some time reading manpages.

First step is to grab series of JPG images from mplayer using webcam:

while true; do
  # grab one frame from webcam and save it as 00000001.jpg
  mplayer tv:// -vo jpeg -frames 1
  # rename 00000001.jpg to something like 1344271221.jpg
  mv 00000001.jpg $(date +%s).jpg
  # sleep 1 second
  sleep 1

Once we are done (break the script with Ctrl+C) we can play the sequence using:

mplayer mf://*.jpg

If we are satisfied with the result we can convert these images to video using mencoder (usually located in the same package as mplayer):

mencoder mf://*.jpg -ovc lavc -o out.avi

For more options about creating video or video formats please read mencoder manpage, but lavc output should be OK for most of you . :-)

See you soon!

Hello everyone!

Today is my last working day at SUSE. I spent wonderful five and a half years at this company. First starting as a package maintainer, learning more and more about the free software movement and its ecosystem. Later I moved to the newly created openSUSE Boosters Team, where I could apply everything I learned about FOSS communities in practice and help to create the best Linux distribution.

Recently I discovered my dormant passion for open hardware, be it analog or digital. I feel that’s where my heart is at the moment and that probably I could do a bigger change in this area.

The good thing is nothing changes from the community side of things. I’ll still be participating in openSUSE development and discussions on the mailinglists or IRC. So, please, put the champaigne back to the fridge, it’s not over yet. :-) If you want to keep in touch and didn’t notice I started using email address instead of the corporate ones some years ago, please change your address entries now.

I’m sure we’ll see each other very soon at some FOSS related event (most probably openSUSE Conference in which organisation I’m actively participating in). That’s why this blogpost is titled “See you soon!” rather than “Goodbye”. And of course, remember to have a lot of fun!

Stabyourself games in openSUSE games repository

In previous blogpost I mentioned my first experiments with LÖVE framework for creating games. Today I found a website run by two friends called Stabyourself. They make games built on this framework and these are simply fabulous! Check out for yourself:

I was so psyched I created packages for all three of them. Simply add the openSUSE Games repository and install packages mari0, orthorobot or nottetris2 respectively to play. Dependency packages like love and lua will be installed automatically, of course.


Update: I was just notified that Not Tetris 2 does not work with LÖVE 0.8.0. I might try to look at it soon.