[Linux] Voice activation/Open mic

devel

Script for Linux to have a button-less microphone:
(it also needs a 50-100ms delay to be set up in Pavucontrol, so the first word isn't cut)

#!/bin/bash

# Voice activation/Open mic
# Presses N key when voice is detected.
# 'threshold' defines the sensivity, `post_tx` - amount of silence before releasing the key.
# Also set 50-100ms delay in the PulseAudio settings.
# Ubuntu 15.04

set -e

threshold=17
post_tx=10

active=
silent_count=0

arecord -D pulse -c 2 -d 0 -f S16_LE -B 100000 -vvv /dev/null 2>&1 | stdbuf -oL sed -n 's/.*\s\([0-9]\+\)%/\1/p'| while read v; do
	if ((v > threshold)); then
		if [ -z "$active" ]; then
			echo 'keydown n'
			active=1
		fi

		silent_count=0
	else
		if [ -n "$active" ] && ((++silent_count > post_tx)); then
			active=
			echo 'keyup n'
		fi
	fi
done | xte