#!/usr/bin/zsh
# script to make sense of compand's parameters
compandy() {
    if [ $# -eq 0 ]; then
        echo -E "usage: $0 {attack} {release} {threshold} {ratio} [knee] [gain] [delay]"
        return 1
    fi
    local atk="${1}" rel="${2}"
    local thresh="${3}" ratio="${4}"
    local knee="${5:-1}" gain="${6:-0}" delay="${7:-0}"
    let 'atk/=1000.'
    let 'rel/=1000.'
    let 'delay/=1000.'
    local end= start=
    let 'end=thresh - thresh/(ratio + 0.0)'
    local start=$thresh
    printf "compand=%.5f|%.5f:%.5f|%.5f:%.1f/%.1f|0/%.2f:%.2f:%.2f:%.1f" \
      $atk $atk $rel $rel $thresh $thresh $end $knee $gain $start
    #echo "compand=$atk|$atk:$rel|$rel:$thresh/$thresh|0/$end:$knee:$gain:$start:$delay"
}
compandy "$@"