Pin osx audio input level, prevent "smart" adjustment.

pinput.sh

#!/usr/bin/env bash
#Keep the gain pegged at the desired input level
poll=3
vol=100
help() {
        cat <<EOF
Usage:
  $0 [-h|--help] [-p|--polling=<polling rate>] [-v|--volume=<volume>]
  -h, --help                   Show help
  -p, --polling=polling_rate   Specify the polling rate in seconds
  -v, --volume=volume          Specify the input volume (0 - 100)
EOF
}
                   
grip() {
        while true; do
                osascript -e "set volume input volume $vol"
                sleep $poll
        done
}
                  
while test $# -gt 0; do
	case "$1" in
		-h|--help)
			help
			exit 0
			;;
		-p)
			shift
			if test $# -gt 0; then
				poll=$1
			else
				echo "polling rate not specified"
				exit 1
			fi
			shift
			;;
                --polling*)
			poll=`echo $1 | sed -e 's/^[^=]*=//g'`
			shift
			;;
                -v)
			shift
			if test $# -gt 0; then
				vol=$1
			else
				echo "volume not specified"
				exit 1
			fi
			shift
			;;
                --volume*)
			vol=`echo $1 | sed -e 's/^[^=]*=//g'`
			shift
			;;
		*)
			echo "Unknown option: $1"
			help
			exit 1
			;;
	esac
done
grip