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SignalFlow: Easy install with Visual Studio Code

The simplest way to start exploring SignalFlow is with the free Visual Studio Code editor. Visual Studio Code can edit interactive Jupyter notebooks, allowing you to run and modify blocks of Python code in real-time, which is a great way to experiment live with audio synthesis.

You'll only need to do this installation process once. Once set up, experimenting with SignalFlow is as simple as opening Visual Studio Code.

1. Install Python

Download and install the latest version of Python.

Download Python

2. Download and install Visual Studio Code

Download and install the latest version of Visual Studio Code.

Download Visual Studio Code

Once installed, open Visual Studio Code.

3. Install the Python and Jupyter extensions

Visual Studio Code requires extensions to be installed to handle Python and Jupyter files.

In Visual Studio Code, select the Extensions icon from in the far-left column, and install the Python and Jupyter extensions by searching for their names and clicking "Install" on each.

Once installation has finished, close the Extensions tab.

4. Create a new workspace

In Visual Studio code, create a new folder to contain your new SignalFlow project:

  • Select File → Open Folder...
  • Select New Folder, and pick a name for your new project folder

Where to put your workspace

You can store your project workspace anywhere on your drive. The workspace can hold multiple notebooks, audio files, etc.

Trusted workspaces

If Visual Studio asks "Do you trust the authors of the files in this folder?", select "Yes, I trust the authors". This is a security mechanism to protect you against untrusted third-party code.

5. Create a notebook

Select File → New File..., and select Jupyter Notebook. You should see the screen layout change to display an empty black text block (in Jupyter terminology, a "cell").

6. Create a Python virtual environment to use

Click the button marked Select Kernel in the top right.

  • Select Python Environments...
  • Select Create Python Environment
  • Select Venv
  • Finally, select the version of Python you just installed.

Multiple versions of Python?

If you already have one or more versions of Python installed, any version from Python 3.8 upwards is fine.

Visual Studio Code will launch into some activity, in which it is installing necessary libraries and creating a Python "virtual environment", which is an isolated area of the filesystem containing all the packages needed for this working space. Working in different virtual environments for different projects is good practice to minimise the likelihood of conflicts and disruptions.

When the setup is complete, the button in the top right should change to say .venv (Python 3.x.x).

Info

New notebooks created within this workspace will share the same Python virtual environment.

7. Install SignalFlow

In the first block, copy and paste the below:

%pip install signalflow

To run the cell, press Ctrl-Enter. After a minute, you should see some output saying Successfully installed signalflow.

Running cells with '.venv' requires the ipykernel package.

If you are given a prompt that the ipykernel package is required, press "Install" to install the package.

You're now all set to start writing code!

8. Start writing code

In a Jupyter interactive notebook, you can write and run multi-line blocks of Python code. Press enter to edit the cell, delete its contents, and paste the below. 

print("Hello")
print("world!")

Press Ctrl-Enter to run the cell. You should see "Hello world!" appear below the cell.

Keyboard shortcuts

  • Navigate between cells with the arrow keys
  • Press enter to begin editing a cell, and escape to end editing and move to select mode
  • In select mode, use b to add a cell after the current cell, and a to add a cell before it
  • To evaluate a cell and move on to the next cell, use ⇧↵ (shift-enter)

9. SignalFlow: Import the library and start audio processing

Clear the first cell, and replace it with:

from signalflow import *

Run the cell with Ctrl-Enter. This command imports all of the SignalFlow commands and classes, and only needs to be run once per session.

Create a new cell by pressing b, and in the new cell, run:

graph = AudioGraph()

This will create and start a new global audio processing graph, using the system's default audio output. You should see the name of the audio device printed to the notebook.

This also needs to be run once per session. In fact, only one global AudioGraph object can be created.

10. SignalFlow: Make some sound

We're finally ready to make some noise!

In a new cell, copy and paste the below:

sine = SineOscillator(440)
panner = StereoPanner(sine, 0.0)
output = panner * 0.1
output.play()

This will create a simple sine wave oscillator, pan it over a stereo pair, attenuate it, and play it from the system's audio output. Hopefully you should now hear a tone playing from your speaker or headphones.

One of the benefits of coding interactively is that you can modify the parameters of a synthesis network while it is running. In a new cell, try modifying the frequency property of the oscillator:

sine.frequency = 880

You should hear it increase in pitch. Try changing the value to something different and re-running the cell.

The pan property of StereoPanner controls its position in the stereo field from left to right, and can range from -1 to 1:

panner.pan = -1

Finally, to stop all playback:

graph.clear()

Next steps

  • Examples: Several example scripts are available for SignalFlow, covering simple control and modulation, FM synthesis, sample granulation, MIDI control, chaotic functions, etc.
  • Configuration: To configure your audio hardware, see AudioGraph configuration.
  • Tutorials: Coming soon
Last update: 2024-10-30
Created: 2023-11-06