The audiogen package provides time domain audio processing tools
using Python generators.
This makes some types of audio sample generation and processing pretty easy:
# mix 440 Hz and 445 Hz tones to get 5 Hz beating
beats = audiogen.mixer(
(audiogen.tone(440), audiogen.tone(445)),
[(constant(1), constant(1)),]
)
The actual samples won't be generated or stored in memory until they're actually consumed – for instance, when they're being written out to disk in a wave file:
with open("output.wav", "wb") as f:
audiogen.sampler.write_wav(f, beats)
Generators' at-consumption-time computation also allows creating infinitely long output, e.g. to stream to speakers rather than a file on disk:
audiogen.sampler.write_wav(sys.stdout, audiogen.tone(440))
Or just:
audiogen.sampler.play(audiogen.tone(440))
You can also use standard generator tools, e.g. the itertools module, to handle audio data:
beep_silence = itertools.chain(audiogen.beep(), audiogen.silence(0.5))
infinite_beeps = itertools.cycle(beep_silence)
audiogen.sampler.write_wav(sys.stdout, infinite_beeps)
The easiest way to play directly to a soundcard output is to use the
audiogen.sampler.play function, which will play your samples using
PyAudio:
import audiogen
import itertools
import sys
audiogen.sampler.play(
itertools.cycle(itertools.chain(audiogen.beep(), audiogen.silence(0.5)))
)
Alternatively, you could write your wave data to stdout, e.g. myaudio.py:
import audiogen
import itertools
import sys
audiogen.sampler.write_wav(
sys.stdout,
itertools.cycle(itertools.chain(audiogen.beep(), audiogen.silence(0.5)))
)
Then pipe to a command line audio player like Sox:
python myaudio.py | play -t wav -
Install with:
$ pip install audiogen $ pip install --allow-external PyAudio --allow-unverified PyAudio PyAudio
PyAudio is optional. If it's not installed, playing audio via the soundcard with
audiogen.sampler.play() will not be available, but generating Wave files –
including for piping to an external player, like sox – will work just fine.
Note that to install PyAudio on Mac OS X, you'll need to first install portaudio:
$ brew install portaudio
Projects built with audiogen:
- koch, a Koch method Morse code trainer and audio generator
- afsk, a ham radio APRS/Bell-202 audio frequency shift keying encoder
Get the source and report any bugs on Github:
https://github.com/casebeer/audiogen
- 0.1.2 - Add band pass and band stop IIR filters; custom beep lengths from @jhobbs
- 0.1.1 - Fix multiplexing bug causing increase in pitch when using mixer() to produce more than one output channel
- 0.1.0 - Breaking changes: new arguments to tone(), play() blocks by default