bzub / bleep

Synthesizer/sequencer written in Golang

bleep

Hobby 8bit/16bit synthesizer/sequencer that can also be used as a virtual MIDI device.

I don't really have any goals for this project, but it's #instructive.

Demo songs / Progress

Old examples first:

1. basic wave forms and delay
2. the shabbiest percussion channel
3. stereo, 16bit, tremelo
4. granular synthesis, sequencer, automations, euclidian rhythms

Features

Things that generate waveforms (generators/):

• Sine wave oscillator
• Square wave oscillator
• Sawtooth wave oscillator
• Triangle wave oscillator
• Pulse wave oscillator
• White noise generator
• .wav playback
• Grain generator
  • Configurable grain size
  • Configurable birth rate
  • Configurable density/nr of generators
  • Configurable speed (=position in sample)
  • Position randomization
  • Windowing functions
  • TODO: pitch control (= grain playback speed)

Things that wrap things that generate waveforms (generators/derived/):

• ADSHR envelopes (attack, decay, sustain, hold, release)
• Transposing generator
• Combining multiple generators into one
• Harmonics generator
• Vocoder
• A filtered generator (see below)

Things that filter (filters/):

• Overdrive filter
• Distortion filter
• Delay filter
• Flanger filter
• Tremelo filter
• First order low pass filter
• Convolution filter
• Low Pass Convolution filter
• High Pass Convolution filter
• Band Pass Convolution filter

Things that mix:

• Channels (channels/)
• Mixer (synth/)

Things that control things that mix:

• Sequencer (sequencer/)
  • Automations

Things that MIDI (midi/):

• MIDI note on, note off, program select, pitch bend
• Basic percussion channel
• Registers as virtual midi device

Things that output:

• .wav output (--record)
• "Realtime" PortAudio output
• Mono or stereo

Usage

Bleep uses Go modules and requires Go 1.11+

git clone github.com/bspaans/bleep
cd bleep
go run main.go

Use --help to see the various options and modes.

Run sequencer patterns

go run main.go --sequencer examples/sequencer_1.yaml

Change instruments banks on sequencer patterns

go run main.go --instruments examples/bank.yaml --percussion examples/percussion_bank.yaml --sequencer examples/sequencer_1.yaml

Record sequencer patterns

go run main.go --sequencer examples/sequencer_1.yaml --record output.wav

Register virtual midi device

go run main.go --midi

Change instruments banks for virtual midi device

go run main.go --instruments examples/bank.yaml --percussion examples/percussion_bank.yaml --midi

Known Issues

alsa/asoundlib.h: No such file or directory

You're missing the alsa headers needed to compile the codebase. On Ubuntu install the libasound2-dev library:

sudo apt-get install libasound2-dev

No package 'portaudio-2.0' found

You're missing the portaudio headers. On Ubuntu install portaudio19-dev:

sudo apt-get install portaudio19-dev