go-audio-service

README

go-audio-service

Important note: this is under heavy development and anything might change anytime!

go-audio-service aims to be a flexible audio synthesizer framework. At the moment the following features are either implemented or planned:

• Generators
  • Rectangle generator
  • Sine generator
  • Sound samples from standard file formats: MP3, WAV
  • Planned: sawtooth and triangle generators
• Filters
  • Compressor
  • Lowpass
  • Planned: highpass, bandpass, reverb etc.
• Modulation capabilities
  • Generators have inputs for AM and FM modulation
• Pluggable architecture
  • Components can be connected to other components to create complex instruments, e.g. connect a sine generator to the FM modulation input of another sine generator
• ADSR Envelope
• Multi-channel mixer
• Output sink provided by gen2brain/malgo
• Planned: LFO as filter
• Planned: high level sound and music player

The inspiration for this library is the CSound library. However instead of writing instruments and notes in a custom language I wanted this to be used programmatically. This way it can be utilized more flexibly.

Requirements

(TODO: test installation procedure and create go1.12 dependencies file)

Install the following package:

go get -u github.com/gen2brain/malgo

For the main example you need additional packages:

• libportmidi and rakyll/portmidi
• gpayer/pixelext (depends on faiface/pixel, see https://github.com/faiface/pixel#requirements for additional requirements)

Ubuntu

sudo apt install libportmidi0

OpenSUSE

zypper in libportmidi0

Finally install the golang packages:

go get -u github.com/rakyll/portmidi
go get -u github.com/faiface/pixel
go get -u github.com/gpayer/pixelext

Examples

Go to into directory examples and run

go run examples.go

Not all examples might work at the moment, especially old singular examples in subdirectories. In the main examples executable select an example by pressing its number.

The most fleshed out example is the Keyboard example. It lets you play with two connected oscillators. Input is read from the keyboard (keys A to K) or from a connected MIDI input. The active MIDI input can be selected from a dropdown in the top-right corner.

Attributions

Code in package filters is translated from C to Go based on github.com/voidqk/sndfilter by Sean Connelly (@voidqk).