b-rad-c / burning-audio

A utility to detect when there is activity from an audio input. The purpose of this project is to control art installations when someone is talking on a microphone, I'll be using it in a burning man project; hence the name.

Burning Audio

A utility to detect when there is activity from an audio input.

The purpose of this project is to control art installations when someone is talking on a microphone, I'll be using it in a burning man project; hence the name.

Requirements

python3, ffmpeg, microphone

This has only been tested on a raspberry pi but will probably work on other linux distros with arecord

references

https://ffmpeg.org/ffmpeg-devices.html#alsa
https://trac.ffmpeg.org/wiki/Capture/ALSA

Installation

sudo apt-get install ffmpeg
sudo pip install git+https://[e-mail]/B_rad_C/burning-audio.git#egg=burning-audio

CLI Usage

(useful for testing)

python -m burningaudio

not talking
not talking
not talking
talking
talking
talking
not talking
talking
talking
not talking
not talking
not talking
not talking
talking
talking

This is an infinite loop, use control+c to exit.

API usage

See inline documentation for explanation of arguments.

for sample in burningaudio.detect_activity():
    if sample is None:
        # no activity
        pass

    else:
        # we have activity (or have not decayed since last activity)
        # sample is a non negative int representing the decoded audio sample,
        # see in-line doc string for more details
        do_something(sample)

This is an infinite loop, kill process or use control+c to exit.

Discover devices

python -m burningaudio -l

null
    Discard all samples (playback) or generate zero samples (capture)
default:CARD=VF0790
    Live! Cam Chat HD VF0790, USB Audio
    Default Audio Device
sysdefault:CARD=VF0790
    Live! Cam Chat HD VF0790, USB Audio
    Default Audio Device
front:CARD=VF0790,DEV=0
    Live! Cam Chat HD VF0790, USB Audio
    Front speakers
    
...

dsnoop:CARD=VF0790,DEV=0
    Live! Cam Chat HD VF0790, USB Audio
    Direct sample snooping device
hw:CARD=VF0790,DEV=0
    Live! Cam Chat HD VF0790, USB Audio
    Direct hardware device without any conversions
plughw:CARD=VF0790,DEV=0
    Live! Cam Chat HD VF0790, USB Audio
    Hardware device with all software conversions

In this example the name of our device is:

hw:CARD=VF0790,DEV=0

Specify device

Using the default device input is fine for testing but for real world use it is recommended to specify the device name to ensure repeatability, as the default device may change unpredictably.

for sample in burningaudio.detect_activity('hw:CARD=VF0790,DEV=0'):
    pass

use --input (-i) on the command line

python -m burningaudio -i hw:CARD=VF0790,DEV=0

Decay

Decay is used to smooth out gaps between words and other short pauses, it can be a float or int representing the number of seconds of silence to return to a no activity state.

python -m burningaudio --decay 0
not talking
not talking
talking
talking
not talking
not talking
talking
talking
not talking
not talking
talking
talking
talking
talking

python -m burningaudio --decay .5
not talking
not talking
not talking
not talking
not talking
not talking
not talking
not talking
not talking
not talking
not talking
not talking
not talking
talking
talking
talking
talking
talking
talking
talking
talking
talking
talking
talking
talking
talking
talking
talking
talking