Monthly Archive for July, 2005

QuickTime 7.0.1: Security enhancements

Published
by
David Wolf
on July 14, 2005
in Tech, Vidget - Discussion and Web
. 1 Comment

QuickTime 7.0.1: Security enhancements

This sucks. QT 7.0.1 no longer lets you access remote web locations from within a Quartz Composition when played using Quicktime Player. No more playing such compositions from the Quicktime Plugin in a web page either. This means no RSS feeds unless you run the composition in Quartz Composer itself or in a custom app.

This is the direction I’m heading anyway (making custom apps) but it means you can no longer distribute a .qtz file or a composition in a .mov which accesses network data and expect it to work on machine running Tiger unless the user has Quartz Composer installed.

These were some of the coolest features of Quartz which I was only just starting to explore before the plug was pulled. Hopefully these features will return some time soon.

Update 18/7/05

I don’t think I made this clear enough but the change was made in response to the potential security issue whereby network access from within a composition wrapped in a .mov file to be used to leak information to a malicious third party when used in combination with Quartz Composer’s ability to access sensitive information about the host computer (computer name, local ip address, current username, results of spotlight searches etc). See the original security report from David Remahl here:

Full-Disclosure: [Full-disclosure] [DR018] Quartz Composer / QuickTime 7 information leakage

Regular (non Quartz Composer) wired Quicktime movies have had the potential to expose some information about the host computer via network access for many years, however it was never to this level and I guess never seen as a security issue. As much as I hope to see things like RSS access return to Quartz Compositions when wrapped in .movs I don’t think it is likely.

It would be virtually impossible to modify Quicktime’s handling of QCs to differentiate between allowing nice, friendly information to be sent (get me links to all the recent images of “x” from flickr.com) and preventing nasty information such as (here is my username and ip address, please start trying to hack into my machine).

Using Quartz Compositions as screen savers expose the same potential risks but I guess in this case you are making a conscious decision to install a piece of software, as opposed to playing a .mov file unaware of its hidden code.

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Template Cinema

Published
by
David Wolf
on July 13, 2005
in Note to self, Video and Web
. 0 Comments

Template Cinema: A short film about nothing, by Thompson & Craighead

Template_Cinema is a collection of “low-tech movies made from existing data appropriated in realtime from the world wide web” by London artists Thomson & Craighead.

The works feature live camera feeds from various locations around the world accompanied by haunting mp3 scores, again appropriated from elsewhere online. Whilst beginning with film leader and ending with credits, these ‘templates’ are filled different every time they are viewed. Some are fixed views, others controlled by unknown ‘directors’.

The Template Cinema project began in 2002 with a networked installation: Short Films about Flying which featured live views of an airfield, snippets of audio from online radio stations and text from message boards.

In my own work I am interested in combining this is the sort of work (network/database cinema) with the real time malleability of sound art and VJ performance.

Also worth a look are these net.arty Web specific artworks and gallery works by Thomson & Craighead.

Quartonian

Published
by
David Wolf
on July 10, 2005
in Tech, Video and Vidget - Discussion
. 1 Comment

Roger Bolton from eskatonia has put together a great Quartz Composer VJ patch complete with on screen previews and keystroke triggering of clips.

Quartonian screen shot

Quartonian is designed to be run in Quartz Composer at full screen and thus has very few on screen controls, in fact with a press of the “~” key you can toggle the whole onscreen display on and off. This makes for a fairly steep initial learning curve for users but, you soon get a feel for using the keyboard and mouse.

Clips (up to 24) must be loaded into ‘Image with movie’ nodes from within a macro patch using Quartz Composer’s editor window to begin. *Hint* it’s the little blue one at the top :-)

Quartonian patch editor screen shot

Also on the eskatonia site is a guide to Quartz Composer for VJ’s with lots of useful links and examples.

Until visiting this page I didn’t realise that you could load .qtz files into ‘Image with movie’ nodes. For example, the ‘Audio Barcode’ .qtz file from the site which reacts to audio input can be loaded into a patch and used as a mask on another clip.

Both Quartonian and the other examples on the site are released under attribution - non commercial - share alike creative commons licenses so users are free to modify and create derivative works.

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Dan Winkler’s this box of earth

Published
by
David Wolf
on July 8, 2005
in Video and Web
. 0 Comments

A new video by Dan Winkler

Dan Winkler has returned to his beautiful abstract video blog this box of earth after a long break. #19 is his latest piece but its worth having a look back at some of his earlier works like #05 which date back to June 2003.

Quartz Composer TV

Published
by
David Wolf
on July 8, 2005
in Tech and Video
. 1 Comment

QCTV, a sample application and source code from Apple's WWDC 05

Quartz Composer QCTV is an application and related source code which demonstrates how to use QC and Xcode to create a TV news style system complete with bluescreen keying and a scrolling text crawl via a RSS feed. It is really good stuff, allowing the user to display either a live camera feed or Quicktime movie over a background. QCTV also features the ability to record the ‘TV show’ to a movie file or stream it out via DV (not while the live camera feed is in operation though).

Pol and the Quartz Composer people at Apple have done an excellent job with their developers documentation and examples. In particular I have found the Quartz Composer Programming Guide: Introduction to Quartz Composer Programming Guide to be most helpful.

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MIAF - LA 6: a Quartz Vidget

Published
by
David Wolf
on July 6, 2005
in Tech, Video and Vidget - Download
. 3 Comments

Screen shot showing the MIAF - LA6 Vidget controls and output

This is the next version of my live video performance (VJ) application. It is an updated version of the program I used for my recent performances at MIAF: Remains To Be Seen and Liquid Architecture 6.

Like the previous version, Bikelights: a Quartz vidget, MIAF-LA6 features one window with controls on the left hand side and a display on the right. It is designed so that I can have the controls on my laptop screen while sending the video from my second monitor output at 640 * 480 to a projector by arranging my monitors like so and dragging the window across.

Screen shot showing monitor arrangement

At some stage I’ll work out how to do two separate windows but this works well for the moment :-)
Screen shot showing controls

Where the previous version only allowed the display of one source image at a time, this version lets the user layer two separate images through a number of effects and outputs. The left hand side of the control area is split two (Source Clip A and Source Clip B). Each area contains four empty text fields where Quicktime movies may be dragged and dropped from the Finder (click in the field to activate it, drag and drop, then hit Enter to set).

Below the four movie path fields is a fifth path field which allows the user to specify a local path to a folder of still images. Again folder paths may also be either typed in manually or dragged from the Finder. After pressing Enter the “# of Images” field should update, letting you know how many images are in the folder you specified. To the left of this field is the “Sequence Duration”, this lets you specify how long (in seconds) it should take to cycle through all of the images in the folder. For example, if you have 8 images and want them to play through at four frames per second second you should set the duration to 2 seconds.

To the right of these fields is a large vertical slider, this lets the user select any one of the four Quicktime Movies or the folder image sequence to process and display.

To control the playback speed of the Quicktime movies, check the “Clip Speed Control” box and move the horizontal slider below. If unchecked the movie will play out at normal speed. If checked the speed will be controlled by a combination of the slider position and live audio analysis (if you have a microphone set up). The far left of the slider is 0 * original speed, the far right is 5 * original speed. If a microphone is connected, the video will jump up to one second forward through the clip with the loudest audio peak.

Below the speed controls are the image controls. These controls allow the user to adjust the saturation, brightness, contrast and colour angle of the clips or image sequences. To leave the Quicktime movie unaffected uncheck the “Image Controls” box.

On the right hand side of the control area is the output stage, the “Renderers”. Each renderer may be switched on and off via a check box and be used to display either source A or source B (or a combination of the two in the case of the “Billboard” and “Inset Image” renderers).

Download miaf2vidget.zip (Mac OS 10.4 required)

Download miaf2quartz.zip (Quartz Composer file)

Download miaf2xcode.zip (Xcode project)

This work is distributed under a Creative Commons Attribution-NonCommercial-ShareAlike 2.5 licence.

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dpwolf @ Liquid Architecture 6

Published
by
David Wolf
on July 2, 2005
in Gigs, Music and Video
. 0 Comments

Liquid Architecture 6, Melbourne Concert 2 with Thomas Brinkmann

I am performing visuals tonight with Jean PΨΨle, bunniboi, Lindsay Cox and Keith_D at The Public Office in West Melbourne as part of Liquid Architecture 6, a festival of sound art.

The night kicks off at 7:30pm with a huge line-up of local and international sound artists including excellent Melbourne AV performers Robin Fox, Dale Nason and Kim Bounds. At around midnight the night will change gears and proceed in a minimal techno orientated direction accompanied by live video on three screens until around 6am. I haven’t done an all night gig for a long time so it should be interesting. We’re going to split up the night into roughly hour long brackets where we will each have a defined role (lighting, matrix switching, main vjing, or support vjing) and will rotate and collaborate in various combinations and permutations.

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Metal Music Machines

Published
by
David Wolf
on July 2, 2005
in Music, Note to self and Vidget - Discussion
. 0 Comments

This week I spent a day improvising and recording audio with Doktorb Robotnik (Adrian Lucas) and was reminded of one of the key aims driving my research. I am developing software devices which allow the user to manipulate audio, video and other data in real time. By creating these works I am attempting to give the user the same feeling of control that I experience when performing live audio, of creating order out of chaos and letting it fall apart again.

Adrian and I have been making improvised sound art / noise / music together, for about 9 years. During this time we have developed various methods for collaborative performance and our production methods have evolved considerably.

Initially we would assemble, manipulate and sequence sound objects on computer in to create finished ‘tracks’, often to accompany short video works. While our process was improvisational in many ways, the combination of unlimited levels of ‘undo’ afforded by the computer software and the goal of producing a piece of a set duration meant that hours of work went into seconds of sound.

A significant shift occurred when we agreed to perform live at a music festival at uni: Rusfest 98 :-). With no idea of exactly what we were doing, we assembled a very basic setup consisting of two multi-effect guitar pedals and two basic synthesisers. Each of the pedals was set to a 2 second delay which let us play various sounds on the synths and have them repeat endlessly. Rather than spending hours obsessing over a few seconds of meticulously cut up audio, we were improvising in real time - in front of an audience. It was exhilarating. We had no interest in melody and our pedals were keeping time, we were free to play with sound. We had constructed a kind of machine for the generation and manipulation of sound in real time and given ourselves a set of variables with which to control it. While our individual noise making machines have diverged technologically since then to consist of a series of interconnected guitar effects pedals which feed back on themselves and a computer running live audio sequencing / processing software, the processes at work in our first performance are still employed.

We build ‘machines’ with fixed number of variables and manipulate them to generate audio in real time. This is exactly what I am doing with images and data in both my Quicktime and Quartz Composer Vidgets.

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