#!/bin/bash

usage() {
	cat <<-EOF
Usage: $0 [files]
EOF
	exit
}

maxj=`getconf _NPROCESSORS_ONLN`
jobs=()

[[ $# -eq 0 ]] && set -- *.flac

for f in "$@" ; do
	case ${f} in
	-*) usage ;;
	esac

	m="${f%.flac}.mp3"
	(
	flac -sdc "${f}" | \
		lame --silent -V 0 -h - "${m}"
	id3cp "${f}" "${m}"
	) &
	jobs+=( $! )
	if [[ ${#jobs[@]} -eq ${maxj} ]] ; then
		wait ${jobs[0]}
		jobs=( ${jobs[@]:1} )
	fi
done

wait