4-Way Crossfader?

[fbglima]

Disclaimer: I'm working on a video edit of a live performance and not a live VJ performance.

I'm trying to figure out if there's a way to manually crossfade between four simultaneously running channels using using either a physical or software controller.

I imagine that the blending would be determined by positioning on an X-Y axis and that the controller would be something like a joystick, but I've never seen anything like this so who knows... From the bit of research I've done already, it seems similar in concept to the Vector Synthesis (correct me if I'm wrong), but with video.

I have a few old video mixing boards (a Panasonic WJ-AVE5 and two Videonics MX-1's) and I LOVE the way crossfading (two channels) with the slider/lever looks -- I've never been able to quite replicate it in Final Cut. At the moment, I'm considering connecting all 3 (2 channels into first mixer, 2 into second, outputs of both mixers into third).
This has a few drawbacks:
1. No HD
2. Lots of levers to control
3. Have to edit live while I shoot (unless I figure out some way to playback my 4 sources perfectly in sync).

I'm willing to deal with all of the above, but if there's a software solution that will eliminate even one of those drawbacks, I'd like to investigate. I'm having a bit of trouble determining if Resolume or GrandVJ or Modul8 will do what I'm looking for and figured I might get a quicker answer here than trying each.

Thanks for any and all help,

Felipe

[dEp]

Originally Posted by fbglima

Disclaimer: I'm working on a video edit of a live performance and not a live VJ performance.

I'm trying to figure out if there's a way to manually crossfade between four simultaneously running channels using using either a physical or software controller.

I'm not sure if I understand you correctly, but I think you could make something like this if you have:

• An XY controller
• A software that is flexible enough (I'd use vvvv, but whatever you like is fine as long as you can assign the controls like you want to)

So, to fade between four channels so that you always have a blend of at least two (like in your Vector Synthesis example), assign the controls so that the vertical crossfades between sources A and B, and the horizontal crossfades between C/D, then blend these together. Essentially the same setup as in this diagram from Wikipedia's Vector Synthesis article:


Right?

[fbglima]

Yes, that wiki is exactly what I'd found that made me think Vector Synthesis was a step in the right direction. I was imagining the controls working more like this however:



vvvv certainly looks interesting, but it looks as though it's more designed to generate and manipulate motion graphics, etc. I only need to cross-dissolve between 4 sources which I'm not otherwise processing at all.

Thanks for the quick response--

[glitchism]

my suggestion would be a MacPro with a LFG4-MM-PE1 pci card and some programming in Max or indeed VVVV. grab 4x full Pal and do your mixing with a joystick. I personally work with both a joystick as with the LFG4, but not in the same setup. The LFG4 is really oke, bit expensive (i thought around £1400).

here's a example with media, no live video. quadmixer in max:

[StereoVJ]

Hi fbglima,
I personally use the IDS Falcon Quattro card to grab and further process four live video streams. It has 16 inputs (4 per ADC). It works under Windows and Linux only. Bought it for USD 700.
4-way mixing is a little bit tricky and cannot be solved with a single XY fader properly. For example, in your diagram, when you want to fade from source A to source C, B and D sources will show up on the output. My first idea is to use an XYZ controller. I made a sketch of the concept, below.
You can go along the edges from any source to another completely bypassing the other two.

Hope that gives some ideas.

Okay, it might not be the most intuitive controller in written history.
Four buttons for the buses would be the best solution. [A] [b] [C] [D] with audo fading. You press the button, the application assigns the selected bus to the invisible side and performs the fade.

[skulpture]

Nice concept. This is like surround sound video mixing!

[many2]

ask yourself this question : how will a 4-way mixer make your show better ?

[Hfour]

I seem to recall having a really really old amplifier with quadraphonic sound. The amp had a joystick type control which remained in position when not in use. I remember removing that component to wire into something else, but never ended up doing so.

The other solution I can think of is using a Korg Kaos Pad with some creative midi controlling software.

[Hfour]

Originally Posted by many2

ask yourself this question : how will a 4-way mixer make your show better ?

The answer doesn't matter right now. For the sake of pure experimentation, the results may lead to an answer in the future.

The more I think of it, the more I believe that this guy is on to something which could potentially take VJs another step even further away from back and forth or channel 'brightness' mixing in hardware format.

[fbglima]

Wow, thank you everyone for the responses -- incredible community here!

Originally Posted by glitchism

my suggestion would be a MacPro with a LFG4-MM-PE1 pci card

Originally Posted by StereoVJ

I personally use the IDS Falcon Quattro card to grab and further process four live video streams.

So it seems like getting my four streams simultaneously into my machine is my first major challenge (don't know why this hadn't occurred me previously…). Your suggestions here are a $700-$2000 PCI card, plus a new computer. I can tell you now this is unfortunately way outside of the budget for this project.

What if instead of using cameras that generate composite signals, I use webcams connected via USB? Is it crazy to think I could take the signals from four of these cameras through a USB hub? Assuming that, could I then process that signal in any of the programs discussed here, or am I limited to surveillance/security camera software?

Originally Posted by StereoVJ

For example, in your diagram, when you want to fade from source A to source C, B and D sources will show up on the output.

That's exactly the idea, though I do see the imperfections in the concept the more I think about it. I couldn't do a xfade from A to B that would look like the one from A to C -- basically, channels would have a different relationship to the channel opposite them than to the ones adjacent…

Originally Posted by StereoVJ

My first idea is to use an XYZ controller. I made a sketch of the concept, below.
You can go along the edges from any source to another completely bypassing the other two.

Wow, this is insane! Probably right that it wouldn't be the most intuitive controller, but many more possible blends than in my 2D example!

Originally Posted by StereoVJ

Four buttons for the buses would be the best solution. [A] [b] [C] [D] with audo fading. You press the button, the application assigns the selected bus to the invisible side and performs the fade.

This is exactly what I'm trying to avoid. If I were attempting a perfectly even transition, then I could easily achieve that in my NLE, but I love using the manual levers/slider on my analog mixing boards because the uneven speed and imperceptible imperfections of the the way I slide from A to B clearly translate in resulting mix! I know it sounds a bit flimsy, but makes all the difference to me.

Originally Posted by skulpture

Nice concept. This is like surround sound video mixing!

I remember hearing once that Surround Sound is mixed using a joystick...

Originally Posted by many2

ask yourself this question : how will a 4-way mixer make your show better ?

Not enough to justify thousands of dollars of expense, but certainly enough to try controlling the three of these at once



Thanks again everyone, I'll keep you all posted on how I end up achieving this.

Trying to make this happen in flash too, so hopefully we'll be able to try the concept out in our browsers soon.