one-bit-instrument(7)						  Numm Tutorials					     one-bit-instrument(7)

NAME
one bit instrument - how to make a gnarly synth with numm-run SYNOPSIS
numm-run FILE DESCRIPTION
In this tutorial we will learn how to live-code a one-bit synthesizer controlled by mouse position. It is intended as a gentle introduc- tion to development with numm-run. To get started, create a text file with the following method stubs: def audio_out(a): pass def video_out(a): pass Save the file as onebit.py, and then launch it with numm-run: numm-run onebit.py You should see a blank window appear. We will now make some sound and light by changing the value of a in the audio_out and video_out functions: def audio_out(a): a[::100] = 2**15 def video_out(a): a.flat[::100] = 255 Save the file, and you should see and hear the sketch update. This is using numpy's array-indexing to turn every hundredth audio sample and pixel-color on. The audio sample rate is by default 44100Hz, so it produces a series of clicks that will be perceived as a 441Hz tone. We can turn this into an instrument by connecting mouse motion to frequency: period = 100 def audio_out(a): a[::period] = 2**15 def video_out(a): a.flat[::period] = 255 def mouse_in(type,px,py,button): global period period = px*1000 Finally, let's use the keyboard to record and jump to notes. The first time you press a key, it records the period, and subsequant depres- sions play the saved period: period = 100 record = {} def audio_out(a): a[::period] = 2**15 def video_out(a): a.flat[::period] = 255 def mouse_in(type,px,py,button): global period period = px*1000 def keyboard_in(type,key): global period if record.has_key(key): period = record[key] elif record.has_key(key): record[] = period SEE ALSO
numm-run(1), numm.getting-started(7), numm.spectral-analysis(7) numm February 2012 one-bit-instrument(7)