The DVI mixer revisited

February 05, 2011 | Posted by The MIDI Thief | 1 Comment
Posted in interview, technology

Many of you have heard of the *Spark D-Fuser DVI mixer project by Toby Harris. It’s based on a DVI scaler from TV-One with the (sexy) name 1T-C2-750 that allows you to mix video from two computers in HD resolution. Toby has been working on a hardware companion for this unit that adds a crossfader, fade to black knob and with some firmware tweaks gives plug and play support for the DualHead2go and the TripleHead2Go devices among a few other things. Due to a hectic schedule and the sheer amount of time it takes to do hardware development, this project has taken a while.

During this time VJ Forums administrator Sleepytom has been very sceptic against Toby’s project claiming that the only addition you’ll need could be done with software, encouraging people to experiment themselves. And recently VJ Fader a.k.a. James Cu (the maker of A/V Mixer) and VJ Leo a.k.a. Leonardo Fernandes Schenkel, announced that they are about to release iMixHD which is an app for Mac & PC built in Processing that controls the 1t-c2-750. VJ Fader claims that he will provide the Processing source code. This release sparked a thread on VJForums. Vade (Anton Marini, one of the men behind Syphon) also announced a Quartz Composer plugin that he has developed together with Toby that controls the DVI-mixer. The VJ forums thread went ugly for a little while but then settled when the main actors decided to share code and knowledge with each other and the public instead of arguing.

Is there still a reason to get Toby’s hardware add-on? Let me tell you like this: I’ve been using the 1T-C2-750 for a few weeks now and I’ve been configuring the unit with instructions from Toby to add the dh2go/th2go resolutions as well as some other settings. It’s easiest done with a Windows program (and for the record I’m a Mac guy, so it’s a little bit more hassle since I have to switch OS). Between Toby’s D-Fuser controller and some firmware tweaks to the TV-One all the correct settings should be there so the only thing you need to worry about is plugging in to the mixer and start mixing.

I had the opportunity to try a beta of the iMixHD software. It only had the functionality shown the video that was published on VJ Forums in January, which was the abilities to to MIDI map the cut buttons and the faders for video source 1 and 2. The app worked very well when I tried it with a Korg Nano Kontrol but the mapping process was a little bit backwards. The big question is what additional control over the t1-c2-750 this software will get and if it will plug’n’play without any further configuration.

So when will Toby’s D-Fuser mixer be available? The short answer is not yet. The initial D-Fuser prototype was using an Arduino clone with RS232 connector rather than USB. The company behind that Arduino clone then ran out of stock and didn’t reply to the approach about making up more boards or taking on manufacture of the whole controller. Toby then took help from Arduino veteran Shawn Bonkowski to turn the controller into a finished product. The controller based on the open-source Arduino PCB files was shown in Berlin in May. But apparently there were errors in the Arduino PCB files that were causing problems – for instance that prototype never sucessfully updated its firmware via USB as an Ardiuno should – and adding features to that unreliable base was making the development even more delayed. At some point the Mbed, an “Arduino on steriods” , showed up on the market offering new possibilities and promising to have all the tricky stuff on its board already, and so a clean start with this has been made. So to my understanding, as soon as the mBed based PCB arrives back for testing, they will be ready to go in to production.

Toby states further: “It’s pretty obvious I/we/Shawn never imagined the *spark d-fuser project could be this delayed, and I really don’t want to have inadvertently stopped anybody from similar home-brew efforts like the original prototype made for the D-Fuse performances. I figured if anyone wanted such a thing bad enough and were capable of figuring out either how to live with the OSD or do the rs232 themselves, they’d just go ahead and do it; I didn’t exactly keep the model a state secret. The all-along decision of not telling everybody just to run out and buy a TV-One and control it via software / their own Arduino setup was based on not wanting there to be a whole wave of units out there stuck without the custom firmware needed to make them plug’n’play and work with the hardware controller. Part of this is I didn’t want any fallout from early adopters getting screwed, and yep part of it was wanting TV-One to get a big order for their units and realise we were a market worth catering for. The interesting recent development is that we might not need the custom firmware I spec’d way back to get the plug’n’play behaviour, but I’m having to reverse engineer some RS232 communication to figure this out. We’ll see, fingers crossed”.

Previous posts written about the dvi-mixer.