Extract CV from Video

Hi all. Greetings from Berlin.

Amazing work on the Hypno and all the YouTube content! Mine should arrive any day now. I’m bubbling with excitement.

I’m very new to the video world but a seasoned eurorack user. So I have probably a newb question…

After learning a bit about analog video signals I imagined a device that could convert a video signal into multiple channels of CV. Brightness and the 3 RGB values. I guess you’d have to input an X,Y coordinate for where on the screen to sample from too (or an area to average). Are there already devices like this on the market and it’s very old news? Or am I a genius stumbling onto something interesting here? :slight_smile:

Thanks in advance.


I like the idea for sure. It reminds me of this photo-sensitive sequencer:

This video is nuts!

The Scannone made me think about putting LDRs on electrode-style suction cups to be able to stick to a screen. I would think a voltage source plus these LDR-electrodes and you’d be cooking!


There was a discussion about this somewhere else recently. Came across a few ideas:

  • DIY a phototransistor circuit and pair it with a tiny screen. Changes in brightness could be output as CV or gates.
  • This interesting module allows you to place your phone on the panel to generate CVs from the screen https://www.nonlinearcircuits.com/modules/p/ldrama
  • Users in LZX land sometimes patch video signals into Sensory Translator. I’ve never gotten this to work very well but YMMV

Curious to hear any other solutions people have!


Wow! Thank you so much for sharing. That video is gold :rofl:

@eddrro This is a bit of a stretch but, Lightjams (amazing nerdy lighting software) can sample hue, saturation, or intensity from a X/Y area of a live video feed (USB, spout, wtvr…) and output a DMX (or MIDI or OSC, etc…) value for however many “pixels” you want to capture. Then if you have a MIDI to CV module in your rack you can output to that and drive Hypno with CV. If instead maybe you have something like an Expert Sleepers ES-9, you could go OSC or MIDI from Lightjams to VCV Rack using trowaSoft cvOSCcv (for OSC, designed by me) or use the built in MIDI-CV module. From there connect to your ES-9 and jam on. If Hypno gets MIDI from host capabilities in the future then you could just go straight form Lightjams to it.

Here is a test pattern in Magic Music Visuals, sampled by Lightjams via Spout, then OSC into VCV Rack controlling the color of the shape on the scope, then that shape and color CV sent through an ES-9 to Structure (I am very excited for my Hypno to arrive as well)


This was just released today and it gives me some fun ideas to use it with fiberoptic light guides.