Vixid VJX16-4 Video Mixer

Vixid’s revolutionary video mixer for VJs, Video Producers, Live Performance and other Video-centric Artists

I’ve had my VJX for half a year now, and for the last couple of months I’d been getting a little complacent. I had the feeling that I fully understood the device and that there weren’t any more surprises coming.

I was wrong.

Vixid Advanced: Keying and Titling Transparency with Channel Masks from Create Digital Media on Vimeo.

The above video features a couple of examples of the VJX’s RGB “Channel Mask” function. This feature is so simple, yet so revolutionary, that I managed to completely gloss over its possibilities until recently.

In a nutshell: The VJX’s keyers all allow you to select a “Track In” parameter, which means that keying data for each layer can be taken from it, or any other layer. So if you’d like to Chromakey a video input with colour information from a computer input, you can do so for each layer individually. Which is super cool.

However, the RGB Masks allow you to use the individual Red, Green, or Blue channel as a mask. This means you can have 3 separate channels worth of masking data sent through an individual layer – through pre-produced mask layers or generative means – and then use this layer’s channels to key the other 3 layers in the mixer!

This ability had me creating videos with various spinning, oscillating and flipping red, green and blue shapes and using them to key multiple camera inputs. I was just about ready to post this information last month, when an idea came to me: Why can’t I use an input to key itself – split a video in half, with the bottom as alpha information, and the top as colour. I’ve uploaded a couple of demo videos to Vimeo so others can give it a try: Squares Key, Titles Key (use the “Download Quicktime version” link in the bottom right column to get the original files).

This technique requires the title/keying input to be split across two layers. If your computer or camera has multiple outputs you can simply plug them into separate layers (I use a Macbook Pro DVI-Video Adapter which has simultaneous S-Video and Composite outs). If you don’t have this capability, most scan converters output S-Video and Composite simultaneously.

Once you’ve got your 2 layers, you need to setup the keying effect:
Layer 1 “Key Layer” – This layer can go to the bottom of the stack and be muted or have its opacity taken down to zero. All it’s used for is keying, and the key ignores the transparency/muting of the layer.
Crop Effect: Up 50% – This prevents the “Title” half of the layer also keying your target layer.
Layer 2 “Title Layer” – This layer needs to have the Scroll effect applied, as well as the Keyer.
Keyer: Type – RedMask (or GreenMask, or even BlueMask if you’re feeling blue). In Track – Layer 1 (pre-FX for the most accurate results).
Scroll Effect: Y -270 (Minus 270) – This moves the coloured “Title” half of the key layer down in to position to be keyed by the “Keyer” half.

Of course, your layer doesn’t necessarily need to be moved down to the bottom of the screen. Both “Key” and “Title” layers can be scrolled around the screen and cropped as necessary.

As with many of these advanced VJX techniques, it takes a while to wrap your brain around what’s going on here, but once you grok this it opens up some huge possibilities. I’m very excited about using blob detection and motion tracking to key out important parts of video feeds live, and I have another project launching next week which uses RGB Masks heavily. This isn’t the last you’ll be seeing of RGB Masks on Vixid.Noisepages.

One Response

  1. Vince

    Nice example.
    That’s a smart way to create titles/overlays with semi-tranparent parts, while having all possible colors and luma available for the title.

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