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pya is a package to support creation and manipulation of audio signals with Python. It uses numpy arrays to store and compute audio signals.
- Documentation: see examples/pya-examples.ipynb for a quick tutorial and Documentation
- Source code: https://github.com/interactive-sonification/pya
It provides:
- Asig - a versatile audio signal class
- Ugen - a subclass of Asig, which offers unit generators such as sine, square, swatooth, noise
- Aserver - an audio server class for queuing and playing Asigs
- Arecorder - an audio recorder class
- Aspec - an audio spectrum class, using rfft as real-valued signals are always implied
- Astft - an audio STFT (short-term Fourier transform) class
- A number of helper functions, e.g. device_info()
pya can be used for
- multi-channel audio processing
- auditory display and sonification
- sound synthesis experiment
- audio applications in general such as games or GUI-enhancements
- signal analysis and plotting
At this time pya is more suitable for offline rendering than realtime.
- Thomas Hermann, Ambient Intelligence Group, Faculty of Technology, Bielefeld University (author and maintainer)
- Jiajun Yang, Ambient Intelligence Group, Faculty of Technology, Bielefeld University (co-author)
- Alexander Neumann, Neurocognitions and Action - Biomechanics, Bielefeld University
- Contributors will be acknowledged here, contributions are welcome.
Note: pya can be installed using pip. But pya uses PyAudio for audio playback and record, and PyAudio 0.2.11 has yet to fully support Python 3.7. So using pip install with Python 3.7 may encounter issues such as portaudio. Solutions are:
-
Anaconda can install non-python packages, so that the easiest way (if applicable) would be to
conda install pyaudio
-
For Mac users, you can
brew install portaudio
beforehand. -
For Linux users, try
sudo apt-get install portaudio19-dev
or equivalent to your distro. -
For Windows users, you can install PyAudio wheel at: https://www.lfd.uci.edu/~gohlke/pythonlibs/#pyaudio
Then pya can be installed using pip:
pip install pya
See pyaudio installation http://people.csail.mit.edu/hubert/pyaudio/#downloads
from pya import *
s = Aserver(bs=1024)
Aserver.default = s # to set as default server
s.boot()
A 1s / 440 Hz sine tone at sampling rate 44100 as channel name 'left':
import numpy as np
signal_array = np.sin(2 * np.pi * 440 * np.linspace(0, 1, 44100))
atone = Asig(signal_array, sr=44100, label='1s sine tone', cn=['left'])
Other ways of creating an Asig object:
asig_int = Asig(44100, sr=44100) # zero array with 44100 samples
asig_float = Asig(2., sr=44100) # float argument, 2 seconds of zero array
asig_str = Asig('./song.wav') # load audio file
asig_ugen = Ugen().square(freq=440, sr=44100, dur=2., amp=0.5) # using Ugen class to create common waveforms
Audio files are also possible using the file path. WAV
should work without issues. MP3
is supported but may raise error if FFmpeg.
If you use Anacodna, installation is quite easy:
conda install -c conda-forge ffmpeg
Otherwise:
- Mac or Linux with brew
brew install ffmpeg
- On Linux
- Install FFmpeg via apt-get:
sudo apt install ffmpeg
- Install FFmpeg via apt-get:
- On Windows
- Download the latest distribution from https://ffmpeg.zeranoe.com/builds/
- Unzip the folder, preferably to
C:\
- Append the FFmpeg binary folder (e.g.
C:\ffmpeg\bin
) to the PATH system variable (How do I set or change the PATH system variable?)
atone.sig
--> The numpy array containing the signal isatone.sr
--> the sampling rateatone.cn
--> the list of custom defined channel namesatone.label
--> a custom set identifier string
atone.play(server=s)
play() uses Aserver.default if server is not specified
to plot the first 1000 samples:
atone[:1000].plot()
to plot the magnitude and phase spectrum:
atone.plot_spectrum()
to plot the spectrum via the Aspec class
atone.to_spec().plot()
to plot the spectrogram via the Astft class
atone.to_stft().plot(ampdb)
- Asigs support multi-channel audio (as columns of the signal array)
a1[:100, :3]
would select the first 100 samples and the first 3 channels,a1[{1.2:2}, ['left']]
would select the channel named 'left' using a time slice from 1
Asig methods usually return an Asig, so methods can be chained, e.g
atone[{0:1.5}].fade_in(0.1).fade_out(0.8).gain(db=-6).plot(lw=0.1).play(rate=0.4, onset=1)
- Please check the examples/pya-examples.ipynb for more examples and details.
- Please get in touch with us if you wish to contribute. We are happy to be involved in the discussion of new features and to receive pull requests.