Im just making 2 separate rects to draw on. they arent really 'in synch', but you can turn auto 1 off and control frame by frame assuming they are the same length.



v a d e //

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On Jan 8, 2006, at 6:06 PM, lists.puredata.info@cefn.com wrote:

I'd like to control two separate projectors playing separate pre-recorded video in synchrony (dual head). Don't know which elements are best to achieve this. Interested to know the components which I should use as there are a few choices.

I've prototyped some simple video control in GEM, on an OpenGL 3D surface as described at http://www.agnula.org/documentation/dp_tutorials/pd_gem/ and the rendering and control of frame speed is perfect. However for the real thing I'll need dual head rendering of two video files, and presumably rendering the frame sequence to an OpenGL pixmap on a texture mapped surface is unnecessary and itself could create some limitations for dual-heading.


THE ALTERNATIVES

The basic questions are...

Video rendering : Gridflow vs. GEM vs. X.
Serial comms : comport vs. serialctl vs. X.

Both dual head rendering and cross-platform serial communications seem to be contentious issues, so I think it might be useful to have ideas from those with experience of either or both of these issues, and can recommend the libraries most likely to work for both my prototyping and deployment environment. I hope to work out the details myself, once I have an idea which libraries should work in principle.

Also if anyone has suggestions as to the strategy I should use to get serial control data in from a Basic Stamp microprocessor, and map two output video streams to two screens simultaneously, this would be very useful.


THE PROJECT

I want to emulate the front and rear window of a car, (footage recorded from two DV cameras in a real car), on opposing projection screens. The reason I'm keen on using PD is  because I need to control the speed of the video in real time as if controlling the speed of the car's accelerator, from zero mph to full video speed and above. Tried this with processing and it was very glitchy.

I'm prototyping on Mac OS X but will deploy probably on an intel machine running debian.

Welcome your contributions.

Cefn
http://cefn.com/curiosity/

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