Robin's Latest Site

Robin's expertise is in audio/video post-production and related hardware/software research and development.

Currently Robin mainly works as contractor for Harrison, Manufacturer of the World's Finest Consoles, acts as core-developer for Ardour and develops a line of professional Audio Plugins.




Berlin is slow, very slow but steady… I had two great weeks of creative holiday, visiting friends & collaborative coders; been hanging out online in the Görlitzer park and read «Robinson Crusoe» during never-ending subway trips.

Most of the Prenzlauer Berg has been taken over by pay-wifi providers, not to mention the tourist commerce. Yet I found the Schleussenkrug in the Tiergarten to be a very comfy place for breakfast and reading email in the sun. Since I was mostly offline during my stay I've postponed the dokwiki pubsub and linux_sound_tags projects.

However I've updated liboauth which bumped into 0.3.3 and I'm making progress on the ardour image compositor software - currently patching ardour adding a video-route instead of re-using route-ui. I'm beginning to loosing track of all the projects but I've also added a jack-audio port to freeJ that I'm gonna link to the A/V decoder back-end during the next weeks.

Besides, the whole field-trip exercise was to gain energy for the Hacker Camp at the picnic-conference starting this Friday. Even though it may not sound very relaxing, it worked out very well. Breaking a few habits does magic from time to time as does Berlin.

I had an unforgettable weekend trip to Rostock - my first time at the ost-see, and I've re-visited the Beelitz Heilstädten where we shot marzipan movie three years ago. The place is still stunning: roof-top forests, gymnasium ruins and never ending tunnels. Arjan has taken a few pictures of me there featuring my new Berlin short-hair cut.

· 16.09.2008 18:03 · Robin Gareus

liboauth 0.3.0

Yet another Sunday without sun in Amsterdam… I spent the afternoon fixing an issue with empty URL paths for liboauth.

After scraping the documentation I choose to

insert a slash before the [first] '?' (or '&' or end of string) if and only if
there is no '/' between the protocol's /:\/[\/]*/ and the delimiter.

It looks like a dirty hack, but checking the BNF this seems perfectly ok. All slashes in the /authority/-part of the URL (userinfo, host) should have been escaped. This was too easy and I had still some coffee left, so I went on to tackle RSA-SHA1 signatures and other open ToDo items..

Openssl gave me quite a headache, that got resolved over an Indian dinner with Florian; he's just back from CERN - angry against bloggers who misinform about the LHC - carrying the spirit of Johnatan R. Ellis: the web strikes back.

With a deep sigh, I've released liboauth 0.3.0 last night. It's the first version that implements the complete oAuth-1.0 spec. I went over four version steps, adding missing functions and a oAuth consumer example. I was tempted to call this a v1.0 or at least v0.9 which may happen during the next weeks. I'm in contact with Marc Powell about integrating liboauth with curl; and the code will definitely come in handy for implementing apache's mod_auth_oauth.

· 25.08.2008 05:25 · Robin Gareus

linux sound tags

Categorizing linux audio applications

As a first step to clean up the tag mess at I started to visualize “the problem”. It turns out there are ~1800 tagged pages with ~200 unique tags1).

Most of the tags go back to headlines in the original data of All applicable headings (<h1>..<h5> and <li><b>..) were used as tags for a given link in a flat structure. However interrelations between the tags (headings) have been maintained by tagging the tags themselves. 57 of the 203 tags are not tagged (orphaned, loose), these are either top-level-tags or new additions that have not yet been categorized. An index of all tags can be generarated at; a text-file is available with the sources below.

The most commonly used tags are:

  154 software_sound_synthesis_and_music_composition_packages
  145 other_documentation_and_newsworthy_items
  137 all_things_jack
  119 midi_software
  115 linux_audio_tools
  113 tools_to_make_tools
  110 signal_analysis_processing_software
  102 on-line_articles


I trashed the initial intention to reduce the number of tags to a manageable amount. On the contrary: some of the multi_word_tags shall be broken up, and the overall conclusion is: We just need a better user-interface to browse and assign tags.

dokubookmark already prototypes a check-box interface to manage tags. For the apps-wiki a tag-cloud or hierarchical display would be needed to ultimately improve usability.

More discoveries

Now made visible, I discovered a bug in the tag-inheritance parser which imported the data from linux-sound to the apps-wiki. There are additional false tags to content where a sub-level heading was not closed. Most prominently affected are SOAL and openAL.

I'm pondering on a re-import of the data but that would require magic to merge the updates. Magic is the cue, so I'm now writing a perl-script to manage, rename and clean up the tags:

Source image of all tags (1.8MB)

The data was generated from the wiki-content (dokuwiki text files) using this greppy shell-script and graphviz. The png/jpeg images turned out to be rather large (2400×2200 pixel ~2MB). I suggest you download look at the SVG or render images from source.


The color of each tag gives a hint on how often it is used. This value is also printed in brackets after each tag-name. red color increases with more common usage. white indicates end-points and the shades of blue/green jump at usage-counts < 20 , < 40 , >= 40.

Arrows should go from parent topic-tag to child tag - but the current script does not filter out back-links so the direction is more or less random. it is not relevant for this analysis anyway.

1) numbers as of august 9 2008
· 21.08.2008 00:22


I've just completed the first round of porting xjadeo to OSX.

On the way to learn about cross-OS video coding and prepare for sodankyla, I've added a native display (carbon/quicktime) and included a mac-style menu-bar to Jadeo instead of using remote-control and qjadeo. Far from perfect but usable, there's still performance improvements on the ToDo-list and surely a bug or two to fix ;)

  • see osxjadeo for download and built instructions.

expect a universal binary DMG and merge with sourceforge-SVN mid next week.
Amending: a DMG for testing is available from here; I've postponed further work until there's more feedback.

· 20.08.2008 22:46 · Robin Gareus what have you done on 8/8/8 ?

I spent the morning reading and been hanging out at Nadya's good by party: Lucky girls attend MIT in roaring 1920 style.

Much of my time the last days went into and related endeavors: On the WWW front I set up a public git repository (using gitosis, gitweb and git-daemon) running on , updated the dokuwiki at and for good measure threw in an ABC-MIDI tutorial on the upcoming wiki.

During the thunderstorm and a short power-outage in Amsterdam Oost (offline!) i gave the 2.6.26 realtime kernel a go and continuted to discuss why it does not work.. ;) - Oh and I've coded a first native OSX-quartz display for xjadeo on my girl-friends Macintosh and can't wait until she comes home so I can take a screenshot - I never though I'd hear me saying that - Thus no screen shot, it'll take me at least two weeks to complete it anyway.

· 09.08.2008 22:29 · Robin Gareus


The magic mirror v2.0.0 - I just made that SVN tag and started wondering about the name - will be presented this Friday (July 11 2008) at Montevideo - the Netherlands Institute for Media Art ( in Amsterdam - the opening is at 17.00.

Frontera is a fancy combination of video-recording, hand-detection and video-projection: It allows the user to interact with a person projected on a touch-screen, where the projection follows the hand of the player. It takes about three minutes to record an avatar of oneself (wiping the screen) and there are two installations at Montevideo allowing to play and record.

We've had lots of fun and finally got to do a few good recordings of ourselves - come and play at the opening or later.

The last days have been busy, there are last minute changes on the frames and we still need to do a final calibration of justpoint. - I spent most of today tweaking the GUI to avoid reflections (of the monitor while recording) but we've managed to cover miles in the last days and even made a small webinterface to browse the recordings… - the software devel went quite smooth, we've made a few extras that we don't need and if I get the time i'll optimize the query for movement detection. - worst task: recalibration after zooming or panning the recording camera.

read more frontera.

View slide-show

· 09.07.2008 23:27 · Robin Gareus

..and beyond - surround sound installation

I've been asked to do a surround sound installation for the ..and Beyond fashion show “Spectacle” in Amsterdam, gonna be fun.

anyMeta 4 - XMPP Publish Subscribe

We finally made it to share social network information, articles, and news via Publish/Subscribe XMPP with the anyMeta4 CMS

A small step for mediamatic but a large step towards data-portability ;)

frontera - the magic mirror

I'll be working on an open source implementation of Lilian Prerez' Frontera project at the NIMK.

Frontera is a touch-screen that projects a pre-recorded video of a player touching the screen at the same position as the user. I'm going to do the whole installation (hand-detection, recording and playback) from-scratch together with Arjan Scherpenisse. the sources will be on sourceforge. - stay tuned.

first one

just spent half a day updating this dokuwiki!

· 30.03.2007 16:45 · wiki administrators
start.txt · Last modified: 22.02.2019 20:59 by rgareus