Audiogen

The audiogen package provides time domain audio processing toolsusing Python generators.

This makes some types of audio sample generation and processing prettyeasy:

# mix 440 Hz and 445 Hz tones to get 5 Hz beatingbeats = 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'reactually consumed – for instance, when they're being written out to diskin a wave file:

with open("output.wav", "wb") as f:    audiogen.sampler.write_wav(f, beats)

Generators' at-consumption-time computation also allows creatinginfinitely long output, e.g. to stream to speakers rather than a file ondisk:

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, tohandle 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)

Soundcard output

The easiest way to play directly to a soundcard output is to use theaudiogen.sampler.play function, which will play your samples usingPyAudio:

import audiogenimport itertoolsimport sysaudiogen.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 audiogenimport itertoolsimport sysaudiogen.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 -

Installation

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 withaudiogen.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

Contributing

Get the source and report any bugs on Github:

https://github.com/casebeer/audiogen

Version history

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 producemore than one output channel
0.1.0 - Breaking changes: new arguments to tone(), play() blocks by default

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