rob.log

I've been too busy the last weeks to keep up with blogging. So here's a few more updates before x-mas. I'm thinking of attending 25c3 and to check out the dokuwiki developer room there. After all kind of Audio/Video coding I think I need a break and write some different languages before heading to FOMS and LCA mid Jan 2009.

I'm following the discussion on oAuth-body signatures which won't be hard to add to liboauth and might also become a requirement for the dokuwiki PubSub plugin; but for the time being I am laying low, lurking on that end.

I've finally improved my knowledge of c-sound - something I've been wanting to do ever since I first heard and learned it at the LAC 2006. - With Wicked in need for a lot of atmospheric sounds I've fired up Algoscore to produce a score and had lots of fun spending hours tweaking csound instruments. For the title song I've used hydrogen and AMSynth; mixing and mastering is due next Tuesday. hang in there.

It's been almost two months since the last post which I mostly spent pushing open-source tools to the limit with film-postproduction.

Looking at the rushed scans for the Wicked offline-edit, I noticed that some sound-clips have gone missing and only the 16 bit versions of the audio have been synced to the new-timecode. No EDL has been provided by Filmmore either. dang.

Before starting to count frames, slates and reels: The scanned pictures contains a printed version of the camera-timecode which was derived from the audio-recorder's SMPTE/LTC. So if one could parse the camera timecode one can relate the original-audio clock to the timecode of the offline-video..

Since the original EDL was no-where to be found and a second scan is not an option, I set out on this unusual workflow:

1. dump timecode for each audio-file
2. decode each video-frame, crop the timecode and OCR it to ASCII text. Then save the frame-number along with each detected timecode.
3. assign audio-files for given timecode to the video-frame, reassign audio-timecode (drop gaps) and write EDL that matches the analyzed video.

I'd estimated it to take 3-4 hours and ended up spending a day:

Already the first step introduced quite some delay: sfinfo does not inform one about extended WAV headers. libsndfile supports it and I was looking for sndfile-info -b but was more quick to write some c-code re-using xjadeo's SMPTE parser and moved on to step two, which surprisingly was much quicker: Using vextract from sodankylä, it took less than a minute until I started to pass frames to an OSC tool. The first test with gocr was a success. I tried with tesseract and ocrad, both of which have a higher setup-cost, require more tuning and even turned out to be less efficient (char-set configuration, processing time). So gocr it is, for good measure I've forked vannotate and in not time I had two text-files: One with audio-, one with video timecode at two AM in the morning.

Step (3) turned out to take most time: I implemented the offset calculation before taking a nap; and spend another two hours to write and debug a perl-script to generate - not an EDL - but an ardour session file. You won't believe how I high I jumped when it loaded the first session with 100 clips automatically arranged on four tracks!

I justed completed step (4): bounce the tracks and master a preview DVD; quite easy with mencoder, dvdauthor and mkisofs. I've used my trusted dvdmaker script.

The sources are available with the sodankylä project and may end up as Plugins or interoperability tools for open-movie-editor, lumiera.org. Contact me if you want to push this project. For what it's worth: I've also prototyped an EDL editor using a AJAX/JSON interface to sodankylä and started to implement having learned from the prototype, but for now I'm back to sound-design. I also need to arrange travel to FOMS 2009, linux.conf.au and I received an invitation to join the SLUG club. I'm really looking forward to escape this murky and damp Amsterdam.

I spent the last days on the Wicked film set; driving the Chevrolet Impala set-car in gorgeous weather with an amazing team in the Amsterdamse Bos. Thanks everyone! Before post-production (and sodankyla development) begins I'm just about to release oauth-utils, preparing for the dokuwiki oAuth plug-in. Oh, a film-website is also on my ToDo list, besides ..well you don't wanna know. Stay tuned for more pictures!

Related to the movie-shooting I've been busy porting libltcsmpte to AVR-C and built myself a LTC SMPTE timecode reader. What else?

Arjan, Eelko and me are going to host the touch-screen workshop based on Frontera's justpoint at the DIY festival in Zuerich, CH. I'm looking forward to that, so I've updated the wordpress at http://fronteraproject.net/, the content and a new release is due around end of November as is the sound-track for Wicked. I'm firing up compiling ardour. See Ya.

I'm just recovering from the picnicnetwork.org conference where I forged some new contacts and renewed many old. The week before picnic we had the chance to build and design interactive installations presented at the conference in a 5 day hackers-camp. We rented a house with 30 people and as you can imagine there was little time for sleep. Besides supporting the camp on oAuth and anyMeta. I've added the breedr on my ToDo stack: A pond filled with sand in which virtual creatures dwell in an environment linked to the internet-world; reacting on internet-traffic, user-profile-changes or interacting directly via RFID triggers. Come with a friend and cross breed web-DNA to make a link.

The source is online at the breedr trac, read more on our project page. Mediamatic has the picture.

I'll cite my friend Luis, whom I teamed up with for the Breedr project: «The group of people that have shared a roof over the last week is pretty amazing. The array of skills, the variety of views, the camaraderie and the relentless commitment on parade over the last week are truly awesome.»

Since Friday I'm hacking almost non-stop for the picnic conference where registered conference visitors keep their online-profile on a RFID-chip (ik-tag or i-tag) which they can use to sign up for workshops, participate in games, make friends/exchange contacts, get consumption vouchers, etc. throughout the conference.

Besides being back coding for mediamatic's anyMeta CMS (here: Community Managemet System), I've teamed up with Luis, Sly, Thijs and Neil to build The Breeder: an installation where you can interact with a virtual creature that «lives on your RFID tag».

Besides feeding the creature with input from your personal-profile and online activity, you can meet with your and other creatures for reproduction at a pond-like portal (beamer, pond with white sand, camera, rfid-readers) that will be exhibited during the conference staring next Wednesday. The Breeder will visualize meta-activity of conference-visitors in a game like environment (processing/java) where creatures can reproduce when their owners meet and recombine genes of their profiles. Furthermore interaction is not limited to the pond: Users can download a screenshot/snapshot of their pet or enter a communication that their creatures stroke up.. - I'm out to walk my amoeba.

It's a very ambitious project, even more so given a 5 days timeframe from idea until deadline.. You can follow development at our project trac/wiki.

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.

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.