Tag: jitter

Audio from Video

Using video to generate audio.

jit.peek~ outputs an audio signal from video matrix data.

(jit.peek~ help)

from cycling74.com

At any point in the the process, matrix data can be tapped to produce an audio signal. Analyzing video is very much like analyzing audio. For example, using envelope following and spectral analysis. Here are examples.


1. jit.peek~-additivesynth.maxpat (in Max/MSP examples/jitter-examples/audio)

Draw a song

By Adam Florin and Joshua Kit Clayton

2. Frame subtraction

By Adam Rokshar


3. Sound Emotion2 – using Macbook built-in camera

By Andreas Wittich


4. jit.peek~-osctrack.maxpat (in Max/MSP examples/jitter-examples/audio)

Derives rhythmic audio data from video. (Using bball.mov)

By cycling74.com

5. Whispering Heights (in Max/MSP examples/jitter-examples/3rd-party/image-to-spectral-filter/whispering_heights.maxpat)

Similar to above but uses video to create a moving spectral filter.

6. Wolframatic.maxpat  (in Max/MSP examples/jitter-examples/other/Wolframatic/)

Fractal generator also generates audio.

By R. Luke Dubois


green screen in Max

Live chroma-key example using the built-in camera.

Hacked from jitter help files…



folder: chroma-key

patch: greenScreen1.maxpat

  • click open (screen grab)
  • click read – to open a movie file
  • click start/stop toggle
  • in the grab viewer, select the background color to chromakey, by clicking with mouse

This really works best with an external camera and a large monochromatic background.


  • Max/MSP – Jitter
  • builtin camera

Web video streaming in Max

Stream realtime video from a web browser into Max or any program that uses Syphon.

CefWithSyphon (developed by Vibeke Bertelsen) launches a web browser and Syphon server. The Max patch operates a Syphon client that receives a video stream from the server and makes it available to Jitter objects.



folder: web-video-streaming

patch: jit.gl.syphonclient.maxhelp

  • jit.gl.syphonclient.mxo:

Note: externals are included with max-projects but can also be downloaded here: http://syphon.v002.info

other dependencies (app) 
  • CefWithSyphon.app

Download the CefWIthSyphon app from here:  https://github.com/vibber/CefWithSyphon – A Mac OS binary is available and has been tested with Mac OS 10.9.2

  • Open the client example /jit.gl.syphonclient.maxhelp in  Max
  • Run the CefWithSyphon app. It will launch a browser
  • The browser content should now stream to the clientcontext window in Max 
  • If not streaming, click the “getavailableservers” message and select the correct server/client from menu objects outlined in red


Leap Motion musical UI for closed eyes

How many musicians do you know that play with their eyes closed? Not many computer music apps allow this. Bloom is an exception.  http://www.generativemusic.com/bloom.html

As an exercise, I tried to make something like Bloom, using Leap Motion. With your eyes closed you can accurately position your hand at the level of eyes, shoulders, hips, etc., And you can quickly move to a point directly outward from your nose, or shoulders. This is the basis of sobriety tests.

The interface, works with a hand motion like sprinkling seeds. Every time you open your hand, it triggers a note based on the height of your hand. It also triggers one of the “Bloom”  circles at the XY position.

The prototype was done in Max/MSP Jitter. It was derived from a “bloom clone” project by John Mayrose at: http://www.johnmayrose.com/maxmsp.html

Here’s an example:



folder: bloom


  • (main patch) circlething.maxpst
  • (poly~ sub-patch) FMPoly2~.maxpat
  • (Leap Motion main-patch) leap-finger-switch.maxpat
  • (Leap Motion sub-patch) leap-switch-test2.maxpat
externals and dependencies

Note: If you don’t have a Leap Motion sensor, you can use a mouse.

If you are using Leap Motion, download the aka.leapmotion external – and add it to your Max file path in options | file preferences: http://akamatsu.org/aka/max/objects/


(if not using Leap Motion sensor, skip to step 4)

  1. Plug in the Leap Motion sensor.
  2. Open leap-finger-switch.maxpat and click the “start” toggle. 
  3. Wave your hand around – it should be detected and displayed
  4. Open circlething.maxpat
  5. If using mouse, just click in the black “circlething” window to play.
  6. If using Leap Motion, click the message box to activate Leap Motion
  7. Then open and close your hand, over the sensor to play
  8. High notes are higher in the window.