Looking at Sound with Jitter

When I am designing sound I use a sonogram and oscilloscope a lot.  the sonogram gives me the spectrum of the sound while the oscilloscope gives me the wave form.  I mainly use the oscilloscope to look for dc offset or in the case of noisy sounds, look for periodicity.  Max/MSP has a built in scope (scope~) but the user cannot pause it or freeze it so therefore I made my own.

To do this I used jit.catch~ to grab audio and turn it into a matrix.  If you don’t know what that is, think of it as an xy plain with a certain amount of dimensions.  The image below is how cycling74 shows what a jitter matrix is.  As you can easily see it is ARGB plains with a dimension of 8×6.  Each box holds a value between 0 and 255.


Once the sound is converted into a matrix we can use jit.graph to graph the information from the matrices.  Jit.graph has 4 different modes which can be used to visualize the waveform in different ways and by adding @frgb you can change the color of the waveform.  The last argument we have to add to the jit.graph object is @clearit 1.  This refreshes the screen every frame and makes it so the wave does not write over itself.  Lastley, a qmetro is used to trigger a new frame to appear.  This acts to slow down the frames and or freeze one.  This qmetro is the entire reason I made my own scope.  It gives me the power to pause and look at an instance of the sound.

Screen Shot 2015-10-14 at 12.22.50 AM

Here is the max patch that I made.  I am using a basic ring modulation and running it through jit.catch~ at mode one (it says mode 0, but @mode 1 is the default).  Qmetro 2 sends a bang every 2 milliseconds, therefore making jit.catch~ release a frame every 2 milliseconds.

*If you like these little tutorials or if there is something you want to see please let me know.

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