Linux computer for laser show

[shrad]

Hi all,

I'm considering installing debian on an old laptop for lasershow use (simply for the lightweight OS advantages)

It seems laserboy runs on linux (read that on the archive) but I might consider writing my own software based on mono or something

Is there a common base for DACs like easylase or other USB DACs to be enumerated via USB, or do they require implementing the interface for each DAC?

It would be great to have a standard SDK on which one could design his own software and tailor it to his needs...

Any input would be appreciated...

I could also use my future i7 laptop from work but I'm limited to my easylase (another dac is not an option for now as I'm not a showman initially)

Thanks a lot for your input!

[james]

If you stay with the idea that laser signals are audio signals, then you can use the Jack audio system architecture to communicate to the DAC. Any multi-channel sound card will be accessible that way and apparently so will the new LaserShark that is in development and posted here on this forum. Jack is supposed to be platform independent, so your efforts might be useful in Windows and Mac-OSX as well.

http://jackaudio.org/

http://www.photonlexicon.com/forums/...-USB-laser-DAC

James.

[shrad]

hmm interesting idea, but I really want to be able to communicate with multiple DACs and a common framework would be nice!

I think I'll give a framework a go, if I manage to find a common base... do anyone have any idea where I could find an easylase DLL or something, along with documentation?

[WookieBoy]

I'm not sure if it's valid for Linux, but I think Dr.Lava on here released a general universal SDK for a long list of DACs including the eatherlase...
You should be able to find the post by searching the forum.

[Stoney3K]

hmm interesting idea, but I really want to be able to communicate with multiple DACs and a common framework would be nice!

I think I'll give a framework a go, if I manage to find a common base... do anyone have any idea where I could find an easylase DLL or something, along with documentation?

I'm also interested in looking into (and co-developing) a unified laser display framework which could also run under Linux.

Communicating with lots of DACs from different manufacturers on a low level is going to be the hard part, even though it is what you'll want if you want complete control over your laser display. Audio APIs can be quite cumbersome, resource demanding and could interfere through unwanted signal processing.

To be honest, I would start by looking at systems like the Ether Dream and pull apart the protocol for that DAC -- the developer is an active forum member here and may be able to give you some pointers.

Personally, I would like to stop working from the traditional 'frame based' paradigm and transition to signal processing on a set of continuous streams of (X, Y and colour intensity) data. After all, that's how the old analog consoles and show tapes were designed as well, which is also a key factor in their fluidity. Using today's processing power, you could construct a very advanced compositing engine for some very impressive shows. Implementing OpenGL commands onto a laser based canvas may even be possible.

[macpod]

I'm also interested in looking into (and co-developing) a unified laser display framework which could also run under Linux.

Communicating with lots of DACs from different manufacturers on a low level is going to be the hard part, even though it is what you'll want if you want complete control over your laser display. Audio APIs can be quite cumbersome, resource demanding and could interfere through unwanted signal processing.

To be honest, I would start by looking at systems like the Ether Dream and pull apart the protocol for that DAC -- the developer is an active forum member here and may be able to give you some pointers.

Personally, I would like to stop working from the traditional 'frame based' paradigm and transition to signal processing on a set of continuous streams of (X, Y and colour intensity) data. After all, that's how the old analog consoles and show tapes were designed as well, which is also a key factor in their fluidity. Using today's processing power, you could construct a very advanced compositing engine for some very impressive shows. Implementing OpenGL commands onto a laser based canvas may even be possible.

I would not consider JACK to be cumbersome nor resource demanding (I had it running on a Raspberry pi and that thing is slow!). It also does not do DSP processing automatically (you have to pipe the stream into an app for it to do that).
All it is is a backbone that lets you easily stream samples continuously (vs 'frame based' which you seem to want to get away from) in a synchronized way which would be perfect for working with multiple dacs.

OpenLase has an OpenGL interface too. It's not complete (dots, lines, beizer curves.. no circles yet) but you can do much already such as display svgs, to opengl-like transforms, convert mpeg videos to laser output on the fly, etc.

Before you toss it to the decide, I would suggest checking it out a little more closely

[shrad]

opengl implementation would be awesome indeed

to second this, I always thought a basic graphic display adapter would be able to provide everything a laser display would need (3 24 bit channels and X/Y) but never gave it a go...

have anyone ever tried this approach? like every laptop now has HDMI with dual screen abilities, it could be a nice feature to use...

but for what I know, ethernet streaming is the way to go now for bandwidth and routability

[macpod]

Why not 32 2048bit channels and X/Y? Might as well use Infiniband too.

You have suggested some absurd specs in my opinion. Why do you need each channel to have such resolution and what has made you arrive at the conclusion ethernet is best?

[shrad]

to second this, I always thought a basic graphic display adapter would be able to provide everything a laser display would need (3 24 bit channels and X/Y) but never gave it a go...

infiniband does not exist as-is, a standard VGA graphic card with basic 3-D hardware exists and is cheap

but for what I know, ethernet streaming is the way to go now for bandwidth and routability

gigabyte bandwidth is available so you can use a heap of ethernet dacs on the same network without saturating, and a manageable gigabit switch can route, filter and isolate segments of your network as you want it to be with reliability, without restriction of unobtainable hardware to dispatch your gear over the scene... standard CAT5-E network cable, a switch or more if you need more than 100 meters...

I'm in no way stating I need infiniband or absurd specs as you might think

I'm just discussing about some existing, available hardware and techniques and the possibility that they would be applicable for analog data streaming... ethernet is the way to go I think, as you can output data from your network card and route it any way from your laptop to your integrated DAC on your projector

graphic adapters which natively contain a 3 channel 24bit dac with graphic treatment capabilities was just a question related to existing tentatives to add opengl capabilities to a laser DAC

I made no conclusion about resolution or anything else, only that ethernet was the best way to go in terms of portability from a lasershow software point of view

UDP can be made to stream broadcasted data within a network in a multi-client way with no error control, and DACs can then talk back TCP/IP with their eventual local error handling, enabling ultra high data throughput

Its a fast answer as I need to leave work, I'll take on it later, this is just a food for thought

[james]

http://laserboy.org/forum/index.php?topic=256.0