signalflow 0.4.1

signalflow

SignalFlow

SignalFlow is a sound synthesis framework designed for clear and concise expression of complex musical ideas. It has an extensive Python API, for fluid audio experimentation in iPython/Jupyter. Its core is written in C++11, so it can also be embedded into other cross-platform applications.

SignalFlow is in alpha status. All interfaces may be subject to change.

Example

from signalflow import *

#--------------------------------------------------------------------------------
# An AudioGraph is made up of a network of interconnected Nodes, which generate
# and process audio. 
#--------------------------------------------------------------------------------
graph = AudioGraph()

#--------------------------------------------------------------------------------
# Passing an array of frequencies creates a stereo output.
#--------------------------------------------------------------------------------
sine = SineOscillator([440, 880])

#--------------------------------------------------------------------------------
# Simple attack/sustain/release envelope with linear curves.
#--------------------------------------------------------------------------------
env = ASREnvelope(0.01, 0.1, 0.5)

#--------------------------------------------------------------------------------
# Use standard arithmetic operations to combine signals. When a multi-channel 
# signal is multiplied by a mono signal, the mono signal is auto-upmixed.
#--------------------------------------------------------------------------------
output = sine * env

#--------------------------------------------------------------------------------
# Connect the output to the graph, and begin playback.
#--------------------------------------------------------------------------------
output.play()
graph.wait()

Installation

SignalFlow requires Python 3.8 or above.

Installation: macOS

macOS

Install an up-to-date version of Python 3 using Homebrew (guide): brew install python3

Install SignalFlow using pip:

pip3 install signalflow

That's it! To test that it is installed successfully, play a test tone by running: signalflow test

From source

To build on macOS from source, install dependencies with Homebrew:

brew install cmake python libsndfile libsoundio

Clone this repository, then build and install with pip:

pip3 install .

Installation: Linux, Raspberry Pi

Linux, Raspberry Pi

SignalFlow supports Linux (verified on Ubuntu 20.04 and Raspberry Pi OS buster) with alsa and pulseaudio backends.

Via pip

Installation via pip is supported for Linux x86_64. To install:

pip3 install signalflow

That's it! To test that it is installed successfully, play a test tone by running: signalflow test.

If installation does not succeed, follow the instructions for building from source below.

From source

To build the Python library from source on Linux, install dependencies with apt:

apt-get install -y git cmake g++ python3-pip libasound2-dev libsndfile1-dev libsoundio-dev fftw3-dev

If you experience an error on Raspberry Pi libf77blas.so.3: cannot open shared object file:

sudo apt-get install -y libatlas-base-dev

Clone this repository, then build and install with pip:

pip3 install .

Installation: Windows

Windows

This is work in progress.

Currently, dependencies need to be downloaded and built by hand. These can be placed anywhere.

• https://github.com/timmb/libsoundio - check out the fix-msvc branch.
  • Use CMake GUI to build libsoundio with Visual Studio 2019 with binaries in a subfolder of that repo named build. (Configure, Generate, Open project, Batch build all configurations)
• https://github.com/libsndfile/libsndfile
  • Use CMake GUI to build libsndfile with Visual Studio 2019 with binaries in a subfolder of that repo named build. (Configure, Generate, Open project, Batch build all configurations)
• Download Windows binaries of FFTW from http://fftw.org/install/windows.html.

To build SignalFlow, use the CMake GUI. Press configure and you will see three empty fields to fill in with the path to the two build folders and the FFTW binaries folder (see above). Set these parameters then press Configure, then Generate then Open. Then build in Visual Studio 2019.

As of 2021-03-03, only the signalflow project has been ported to build correctly on Windows. Only tested in x64 and for Debug builds. Tested using Visual Studio 2019.

Installation: C++ only (no Python layer)

To build and install the C++ core without the Python binding layer:

mkdir build
cd build
cmake ..
make -j8

Examples

See examples/python for a number of example scripts.

Documentation

More detailed documentation can be found at signalflow.dev.

Node classes

The following Node classes are currently included with the base distribution:

Category	Classes
Analysis	CrossCorrelate, OnsetDetector, VampAnalysis
Buffer	BeatCutter, BufferLooper, BufferPlayer, BufferRecorder, FeedbackBufferReader, FeedbackBufferWriter, GrainSegments, Granulator, SegmentPlayer
Control	MouseX, MouseY, MouseDown
Envelope	ADSREnvelope, ASREnvelope, DetectSilence, Envelope, Line, RectangularEnvelope
Fft	FFTContinuousPhaseVocoder, FFTConvolve, FFT, FFTNode, FFTOpNode, FFTFindPeaks, IFFT, FFTLPF, FFTNoiseGate, FFTPhaseVocoder, FFTTonality, FFTZeroPhase
Operators	Add, AmplitudeToDecibels, DecibelsToAmplitude, ChannelArray, ChannelMixer, ChannelSelect, Equal, NotEqual, GreaterThan, GreaterThanOrEqual, LessThan, LessThanOrEqual, Modulo, Abs, If, Divide, FrequencyToMidiNote, MidiNoteToFrequency, Multiply, Pow, RoundToScale, Round, ScaleLinExp, ScaleLinLin, Subtract, Sum, Sin, Cos, Tan, Tanh
Oscillators	Constant, Impulse, LFO, SawLFO, SawOscillator, SineLFO, SineOscillator, SquareLFO, SquareOscillator, TriangleLFO, TriangleOscillator, Wavetable, Wavetable2D
Processors	Clip, Fold, Smooth, WetDry, Wrap
Processors: Delays	AllpassDelay, CombDelay, OneTapDelay, Stutter
Processors: Distortion	Resample, SampleAndHold, Squiz, WaveShaper
Processors: Dynamics	Compressor, Gate, Maximiser, RMS
Processors: Filters	BiquadFilter, EQ, MoogVCF, SVFilter
Processors: Panning	AzimuthPanner, ChannelPanner, SpatialPanner, StereoBalance, StereoPanner, StereoWidth
Sequencing	ClockDivider, Counter, Euclidean, FlipFlop, ImpulseSequence, Index, Latch, Sequence
Stochastic	Logistic, PinkNoise, RandomBrownian, RandomChoice, RandomCoin, RandomExponentialDist, RandomExponential, RandomGaussian, RandomImpulseSequence, RandomImpulse, RandomUniform, StochasticNode, WhiteNoise

Contributors

Thanks to the following contributors:

• Arthur Carabott (@acarabott), Tim Murray-Browne (@timmb): Windows support
• Dan Stowell (@danstowell): Build improvements
• Marc Fargas (@telenieko): Generous donation of the signalflow pypi namespace