Getting Started

python3 setup.py build_ext --inplace

python3 setup.py develop

Running the tests

Tests can be run via with

python3 setup.py test

Safety First

As always when programming with sound: Unplug your headphones or be very sure of what you are doing! Also with low headphone volume bugs in the code can result in very unpleasant loud noises which could probably impair your hearing. Be careful!

Klang Primer

Klang provides various audio related blocks. Every block can have multiple in- and outputs and by connecting them with each other we can define our network. Once we are finished with patching we can run our network with by calling run_klang(*blocks). This function only needs some blocks which belong to the network. It will then automatically discovers the other blocks of the network and deduce an appropriate block execution order.

In the following script we create a 440 Hz sine oscillator which output gets send to the sound card.

from klang.audio import Oscillator, Dac
from klang.klang import run_klang

# Init blocks
osc = Oscillator(frequency=440.)
dac = Dac(nChannels=1)

# Define network
osc.output.connect(dac.input)

# Run it
run_klang(dac)

Audio can be written to disk as a WAV file with the filepath argument.

run_klang(*blocks, filepath='some/filepath.wav')

# Pipe operator
a | b | c

# Is equivalanet to:
# >>> a.output.connect(b.input)
# ... b.output.connect(c.input)

# Mix operator
mixer = a + b + c

# Is equivalanet to:
# >>> mixer = Mixer(nInputs=0)
# ... mixer.add_new_channel()
# ... a.output.connect(mixer.inputs[-1])
# ... mixer.add_new_channel()
# ... b.output.connect(mixer.inputs[-1])
# ... mixer.add_new_channel()
# ... c.output.connect(mixer.inputs[-1])

Examples

See the examples directory with a couple example script which illustrate the core functionality of Klang. Currently there are:

• hello_world.py: 440 Hz sine wave generator

• aeolian_arp.py: More fun with random ever changing arpeggios.

• arpeggiator_demo.py: Two synthesizer patch with an arpeggiator and some sound effects

• audio_file_demo.py: Looped audio file playback (gong.wav sample) with audio effects

• haunting_envelopes.py: Multiple oscillators controlled by looping envelopes

• micro_rhythm_demo.py: Kick and Hi-Hat pattern where the latter is phrased with a micro rhythm

• reverberation_demo.py: Ambient loop showcasing the reverb effect.

• sequencer_demo.py: Techno patch with sequencer

• synthesizer_demo.py: This has to be started as root. Computer keyboard playable monophonic synthesizer

• tempo_aware_effects.py: Modulated noise with time synced effects

Coding Style

PEP8 / Google flavored. With the one exception for variable and argument names (camelCase). Function and in methods are snake_case().

Author

• Alexander Theler (GitHub)

Acknowledgments

Thanks for the support and inputs!

• Nico Neureiter

• Andreas Steiner

• Lawrence Markwalder