rg42.org aka. Robin Gareus blog

..and beyond - surround sound installation

2008-06-29T18:14:57+00:00

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

news

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anyMeta 4 - XMPP Publish Subscribe

2008-06-29T18:13:38+00:00

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 ;)

news

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back from Finland

2008-08-20T22:21:47+00:00

After some creative interlude we eventually completed Carolina's trip from Ushuaia all the way down south to NordKapp, spending two weeks in Finland's Lappland on the way. - gorgeous and relaxing.

Besides an unbelievable ammount of unripe berries we did encounter too many mosquitoes (not bugs and luckily no sand-flies), yet found free-wifi in the most unexpected spots under the midnight sun.

Starting off with the night train from Helsinki to the midnight-sun film-festival in Sodankylä..

small picture gallery

news

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breedr

2008-10-06T11:34:13+00:00

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.»

news, FLOSS, installation

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DIY festival

2008-12-14T23:26:43+00:00

I've been one of the lucky persons to have been at the diyfestival.ch last weekend. A festival for art and technology hosted at the Dynamo in Zürich. Apart from there amazing collection of Theremins, there were quite some impressive installations, performances and talks.

Under the motto do it ~~yourself~~ together; we've conducted a touch-screen workshop based on frontera and http://fronteraproject.net. The standards were quite high: One team set up improvised screens using a beamer and two web-cams. While an other team worked with pure-data, MAX/MSP|| and processing.org|processing on interaction and design. Communication between the screen and visualization software was done with OSC. We ended up with a virtual Theremin, some touchable flame/interactive flare animations and even improved justpoint software tools with long awaited user-feedback. Really impressive for only an afternoon of work.

It's been one of the best hands-on workshops and even better you had an amazing taste for music and community. I had a great time. Many thanks to the organizers of the festival and anyone involved.

News

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Tasmania & Melbourne January/February 2009

2009-03-15T14:06:44+00:00

slideshow

news

first one

2008-08-20T22:22:05+00:00

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FOMS 2009

2009-02-01T05:25:05+00:00

This years FOMS (Foundations of Open Media Software) Workshop took place in Hobart, Tasmania and has not only been fun but also a great success!

The focus was on video & film, development of multimedia and collaborative video editing software such a metavid, pad.ma and videobin as well as free video codecs: dirac and ogg.

Quite a few of the short-term Community Goals have been tackled, not only resulting in interesting discussion on ffmpeg-devel, but also yielding funding for open media now to publicly document codecs and prior art as an anti-patent strategy. linuxfilm.org started to index FLOSS authoring tools as a first step to indicate gaps for a professional workflow and and and..

FOMS was a very busy two days, extending into a multimedia mini-conf at LCA and quite a few days of hacking thereafter, not to mention the T42 bar evening excursions.

video, news, floss

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frontera

2008-08-20T22:21:57+00:00

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 (http://nimk.nl) 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.

frontera - the magic mirror

2008-07-01T15:09:25+00:00

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.

News, FLOSS, Video

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liboauth 0.3.0

2008-08-25T03:53:38+00:00

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 by 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..

FLOSS, NEWS, WWW

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linux film browsing

2009-01-01T16:01:00+00:00

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linux sound tags

2008-08-11T02:28:20+00:00

Categorizing linux audio applications

As a first step to clean up the tag mess at http://apps.linuxaudio.org 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 linux-sound.org. 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 apps.linuxaudio.org; 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

Conclusion

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

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

image of all tags
image - only categorized tags
image - only loose tags
graphviz ''.dot'' sources - unzip and process eg. fdp tags.dot -Tpng > graph_all.png
lao-tags-list.txt - text file with all tags

Legend

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.

news, www

¹⁾ numbers as of august 9 2008

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linuxaudio.org

2008-08-09T20:31:40+00:00

..so what have you done on 8/8/8 ?

I spent the morning reading http://dyne.org/first_dharma_dyne.pdf 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 linuxaudio.org and related endeavors: On the WWW front I set up a public git repository (using gitosis, gitweb and git-daemon) running on http://git.linuxaudio.org/ , updated the dokuwiki at http://apps.linuxaudio.org/ and for good measure threw in an ABC-MIDI tutorial on the upcoming linuxaudio.org 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.

news, FLOSS

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OSXjadeo

2008-12-17T18:22:03+00:00

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.

FLOSS, VIDEO, JACK

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picnic08

2008-09-21T22:54:56+00:00

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.

news, installation

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Qjackctl Dbus

2010-01-10T21:39:19+00:00

A while ago I've written a patch to qjackctl which adds DBUS support to start and stop the JACK audio server. It's available and enabled by default in qjackctl from version 0.3.4.11 upwards.

The main use-case for it is to bring up the JACK server after a suspend/resume cycle on laptops. More information about this is available on a Wiki Page. This blog will just give minimal usage information to tease you :)

An example script to re-launch JACK with the last chosen preset looks like this:

/etc/pm/sleep.d/90qjackctl.sh

#!/bin/bash
case $1 in
  thaw|resume)
    (sleep 4 ; dbus-send --system /org/rncbc/qjackctl org.rncbc.qjackctl.start)&
    ;;
  *)
    ;;
esac

audio, floss, jack

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reogg - Prepare audio-files for radio loops

2009-12-09T00:53:36+00:00

Did you ever want to automate live audio streaming from the command-line? Well, I do. To cut it short the requirements here were:

command-line (terminal) only
generate one long stream - concatenate all songs
retain (id3) tags
stream Ogg/Vorbis to an icecast server

In principle one can simply concatenate OGG files and use oggfwd to send it to icecast. However most players (in particular mplayer) will produce garbled output when mixing OGG files with different bitrate/samplerate/channels in one stream. Furthermore some input files may not be OGG/Vorbis encoded in the first place.

To remedy the situation, here's a simple shell-script that converts all files in a given folder to a common format and copies over the id3 tags. You'll need to have oggenc, oggdec, mpg321, flac123 and id3tool installed.

You can download the script from the repository, but it's simple enough to be printed here:

view reogg.sh source

#!/bin/sh
# reogg.sh:
#  converts audio files in SRC folder to a common OGG format which allows to
#  concatenate the resulting files.

SRC=${1-"/tmp/input"}
DST={$2-"/tmp/media"}

mkdir -p ${DST}
IFS=$'\n'
for file in $(ls ${SRC}); do
  DEC=""
  echo "${file}" | grep -e "\.mp3$"  >/dev/null && DEC="mpg321 -q -w- "
  echo "${file}" | grep -e "\.ogg$"  >/dev/null && DEC="oggdec -Q -o- "
  echo "${file}" | grep -e "\.flac$" >/dev/null && DEC="flac123 -q -w- "

  test -z "${DEC}"         && continue;
  test -r "${SRC}/${file}" || continue;

  NFN=$(echo ${file} | sed 's/flac$/ogg/' | sed 's/mp3$/ogg/')

  echo "${file}" | grep -e "\.mp3$"  >/dev/null && \
  TAG=$(id3tool "${SRC}/${file}" \
        | sed 's/"/\\"/g' \
        | awk '/^Song Title/{printf "-t \"%s\" ",substr($0,13);}
               /^Artist/    {printf "-a \"%s\" ",substr($0,10);}
               /^Album/     {printf "-l \"%s\" ",substr($0,9);}
               /^Genre/     {printf "-G \"%s\" ",substr($0,9);}
               /^Track/     {printf "-N \"%s\" ",substr($0,9);}')

  echo "${file}" | grep -e "\.ogg$"  >/dev/null && \
  TAG=$(ogginfo "${SRC}/${file}" \
        | sed 's/"/\\"/g' \
        | awk 'BEGIN{IGNORECASE=1;}
               /Title=/      {printf "-t \"%s\" ",substr($0,8);}
               /Artist=/     {printf "-a \"%s\" ",substr($0,9);}
               /Album=/      {printf "-l \"%s\" ",substr($0,8);}
               /Genre=/      {printf "-G \"%s\" ",substr($0,8);}
               /Tracknumber=/{printf "-N \"%s\" ",substr($0,14);}')

  echo "#-- FILE: ${file}"
  CMD="$DEC \"${SRC}/${file}\""
  CMD+="| oggenc --resample 44100 -q 6 -o \"${DST}/${NFN}\" ${TAG} -"
  echo "${CMD}"
  eval $CMD || exit
  echo
done

To transmit the converted files repeatedly to an icecast server I run the following shell script in a GNU Screen:

view loop_ice.sh source

#!/bin/sh

FILES=$(ls media/*.ogg)

function loopcat {
  while true; do
    # TODO: optionally randomize $FILES here..
    cat $FILES
  done
}

while true; do
  loopcat \
  | oggfwd localhost 8000 password -p -g "Genre" -n "Title" -d "Description" mountpoint.ogg;
  echo "---- LOST CONNECTION ----"
  sleep 2
done

If you find these scripts useful or want to suggest some improvements.. drop me a word:

floss, linux, audio

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Roadtriping through the Middle East

2010-01-08T17:35:58+00:00

Tres bonne année 2010. I'm just back from a three week vacation and my luggage is still somewhere in Bucharest..

Well, let me start from the beginning: My old friend Florian relocated from Amsterdam, NL to Tel Aviv, IL. He owns a pretty cool Mini-Cooper Convertible and the most obvious way to get it down there was - of course - just drive.. After a bit of preparation - ie. to get a Visa for Syria, some change some Euros into Baksheesh suitable currencies and organize a flight back - we hit the road on December 13 2009. Carolina in the back, Florian and me on the front-seats. 10 days, 11 countries, 5500km.

Amsterdam → Munich → (Villach) → (Ljubljana) → (Zagreb) → Beograd → Sofia → Istanbul → (Akçakoca/Black Sea) → Göreme → حلب/Aleppo → دِمَشقُ‎/Damascus → (عمّان‎/Amman) → البتراء/Petra → (אֵילַת‎/Eilat/Red Sea) → רְחוֹבוֹת/Rehovot

Our deadline was x-mas, so in the beginning we blasted through with almost no stops - known territory - through snow-storms to Beograd where we stayed in a boat-hostel on the Danube river and had 15 cm of snow on the car next morning.. Passing into Bulgaria we left the European-winter behind and welcomed the sun with some Vodka in Sofia. We were on the road every day, apart from Istanbul and Damascus where we stayed two days each. Sounds fast, well it was, but so were we: We had enough time to discover major cities and landmarks on the way. Heck we even did a full day hike around Petra. Looking back, we could have taken 3 Months for the whole journey.

Having been in Istanbul before, the most stunning part of the journey started with the border-crossing into Syria. It took us 90mins to clear customs, which is very fast by Syrian standards, but apparently we got lucky and found the right people to talk to. Aleppo (Haleb) was a culture shock and well worth the stay. It's a messy, dirty and crowded place full of Arab atmosphere. It was by far the largest non-touristic city on our way, buzzing with life that most of the time made no sense to us: “Is that a bank or are they selling passports there?”. While it was sometimes hard to communicate, the people were really friendly and helpful. By the way, parking the car in the Sheraton basement for a night cost just the same as our hotel-room for 3 persons: 1000 Syrian Pound.

Next stop: Damascus. The oldest still inhabited city in the world. Our stay in the Damascus Hostel brought yet another cool adventure. It is located in a tower of the old-city wall and unifies ancient Syrian style, willful design and pleasant hospitality in an adventurous location. Our way in was to climb the old-city wall by rope-ladder. The owner - Raymond - and his team were not only forthcoming and funny but also really helpful, sharing local secrets and advice that got us started exploring Damascus in a way not described in any tour guide. After traveling the north of Syria on our own this suddenly felt like being with a family. The old-city is a huge Labyrinth shared by Christians, Muslims and a few Jews. Damascus is very diverse in all accounts: architecture, people and shops. Lot's to experience, hard to describe..

Unforgettable in Syria is the portrait of Bashar al-Assad, just because it's everywhere you can look at. I also have to say it's the region with the best food - only contested by the Israeli Hummus and Shakshouka..

On we went, passed Amman, and drove to Petra. What we thought would be a few hours of visiting turned into a full day impressive hiking excursion. The site is breathtaking. We took more images there than on all other days combined.. still you best go there for yourself.

Exhausted from the day, we made it just in time to Aqaba before the border-control closes. You expect a international crossing to be signposted, but there's no sign, nothing, we needed to ask a Taxi to drive ahead of us to find Eilat. Crossing into Israel was yet another experience. The good thing: you know what to expect and that everything is pretty safe. The downside: “Please take everything out of the car.” We ask: “Well, we have accumulated quite a bit of trash and what about those engine-oil and gas canisters?” The reply was simple: “If we say everything, we mean everything.” . So they ended up x-raying our rubbish before we could throw it away.. At least it was good to clean out the car, and the customs officer was fascinated, too. He drove an extra round after the inspection because it was his first Mini.. After a late dinner on the red-sea we took off through the dessert - amazing star-gazing - and arrived in Rehovot (close to Tel Aviv) at two in the morning on x-mas day.

Image-Slideshow of the Road-trip

While Florian flew back to see his kid on x-mas just the day after we arrived, Carolina and me stayed 10 days in Tel Aviv, visiting friends, Yarriv's parents and grave. Toured to the dead-sea and Jerusalem; celebrated 2010 at a friend's place in Yafo; went swimming on new-years day.. in short we had a pretty good time: Israeli winter feels like a summer in Amsterdam (though Carolina says that BS. She says: “There is no summer in A'dam and the sea is much more clean and warm in Israel”).

After all the great experiences there had to go something wrong, right? Right. Due to snow chaos in Europe the flights were delayed.. My trip to Paris went pretty smooth after all, however my luggage got lost halfway. I still hope it will show up - it contains almost all my clothes, a hand-made Shisha from Syria and my digital camera - but it's already been 2 days without update on it. Carolina was even less lucky: After waiting 4 hours on board without starting she got a nice hotel-room in Tel Aviv, before going via Riga (yet another hotel) and Stockholm to Amsterdam.. Picture Gallery of excursions to the Dead-Sea and Jerusalem

news

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rt2460 and linux 2.6.31

2009-09-18T11:09:36+00:00

As of linux 2.6.31 there is no mainline support for the Ralink rt2680 Wifi chipset. While there is an official driver provided by Ralinktech, it is incompatible with 2.6.31 due to the fact that post 2.6.29 the kernel's net_device_ops API has changed and 2.6.31 also removed CONFIG_COMPAT_NET_DEV_OPS backwards compatibility.

So I came up with a small patch to the Ralink driver.

The solution is to get the module source from http://www.ralinktech.com/support.php?s=2 and apply the patch before compilation.

development, linux

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slowlin

2008-10-06T11:38:14+00:00

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.

news

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Thinkpad smapi and Realtime Linux

2009-11-12T21:26:23+00:00

The tp_smapi driver provides for Battery charge/discharge control and improved stability for the HDAPS driver. However the latest version (as of writing 0.40) does not work with a real-time patched Linux-kernel.

The problem is that rt-linux uses a new mechanism for mutex-locking, which allows preemption and is incompatible with current Linux-mainline. In order to get the tp_smapi driver compile with rt-linux you need to replace the MUTEX locks. I came up with a simple patch that applies to tp_smapi 0.40 to just do that.

tp_smapi-rt.diff

Tested with linux 2.6.31.6-rt19. More information on tp_smapi can be found at http://www.thinkwiki.org/wiki/Tp_smapi

Enjoy.

development, linux

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Unusual Workflow

2008-12-17T18:20:23+00:00

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:

dump timecode for each audio-file
decode each video-frame, crop the timecode and OCR it to ASCII text. Then save the frame-number along with each detected timecode.
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.

FLOSS, Video, News

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wicked days

2008-12-17T18:22:45+00:00

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.

NEWS

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Wicked Game

2008-12-14T22:43:50+00:00

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.

News, Video, Musix

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World Skin - a Photo Safari in the Land of War

2010-02-04T11:29:14+00:00

I spent last week at V2_ in Rotterdam setting up WorldSkin - an Interactive A/V Installation by renowned artist Maurice Benayoun - for presentation during the International Film Festival Rotterdam 2010.

A visit to World Skin is a poignant experience. Armed with a camera, visitors are placed in a sinister war zone that is visualized on a large projection screen in 3D animation and video. By operating photo cameras visitors may take pictures of the war scenes and experience how the camera becomes a 'weapon' that enables them to wipe out the projected images. Only the outline of the taken picture is left as a silhouette in the projection. Visitors can take a print of the photos they shot with them.

World Skin was first presented 1997 and win the Golden Nica Award at the Ars Electronica Festival in Linz 1998.

The Implementation:

The original version ran on a SGI Onyx System. This years installation is a re-design using openGL, openAL and openCV but featuring the original 1997 Graphics by Raphaël Melki and 4.1 Surround-Sound from Jean-Baptiste Barrièr.

The navigation:

Only the driver using a “wand” (aka Bluetooth Gamepad) can decide about the group trip. In this way, he has the role of a “bus driver”. Everyone can ask about the path alterations.

The photographers:

The participants are active. They have to decide about the group's movements. Otherwise they cannot take pictures of what they are seeing. Several SLR cameras hanging from the ceiling allow them to take photos. Instead of opening its shutter to capture the image, the camera sends coordinates to the computer at the time of release.

The taken shots:

With the camera - a old-fashioned SLR spiked with a 3D tracking system - the visitor can frame the virtual show at leisure. He chooses angles, frames and release time.

The triangulation is implemented with Wii-accelerometers for tilt and rotation (Pitch & Roll) mounted in the Camera, while a web-cam located above the front-screen combined with openCV software is used for detecting the position and horizontal angle (Yaw) of the cameras. Thus, the machine can compute the frame corresponding to the viewer, in relation to the scene and time of the shot.

The World Skin:

For each shot, the corresponding surface (divided into silhouette fragments) is removed from the virtual databases. It looks like a white projection made the set pixels disappear, covered by the camera field. The white fragments constitute a rectangle (the frame), only from the exact point of view of the shot. In other words, the perspective takes over again and we can discover the white surface fragments vanishing into the set depth.

The photography:

After the session, the visitor exits the CAVE and finds a printer and a screen presenting the website, where the last shots are sent in real time. He can leave the place with a printed copy of the shots.

(If Flash is installed JavaScript is activated, you can watch a video inside this web page.)

video, installation, audio

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