#!/bin/bash

if [ "$1" == "" ]; then
  PROG=`basename $0`
  echo ""
  echo "  build-saudio enhances audio quality of poorly recorded telephone "
  echo "  conversations by converging left and right channels into a single "
  echo "  channel of substantial higher bitrate. The low sample rate is then "
  echo "  converted to 44.1 kHz and can then be recorded on a old-fashioned "
  echo "  audio cd-rom in (j)oint stereo "
  echo ""
  echo "  Usage : $PROG \"fancy.file_ - _name.mp3\" "
  echo ""
  echo " build-saudio v0.1.1 has been tested with : "
  echo ""
  echo "          vbr2linear.custom version: 1.4.1 "
  echo "          mpg123 version: 0.68, 1.3.1, 1.12.1 and 1.16.0 "
  echo "          sox: Version 12.17.4 and sox: SoX v14.4.1 "
  echo "          LAME version 3.92, LAME 64bits version 3.98.4."
  echo "          and LAME 64bits version 3.99.5 (http://lame.sf.net) "
  echo ""
else
	MPG_VERSION=`mpg123 --version | awk '{print $2}'`
	SOX_VERSION=`sox --version | awk '{print $3}'`
	VBR_TEMP=/tmp/vbr2linear.$$

	if [ "$MPG_VERSION" == "1.16.0" ]; then
		mpg123 -n 10 -o dummy "$1" > $VBR_TEMP 2>&1
	fi
	if [ "$MPG_VERSION" == "1.12.1" ]; then
		mpg123 -n 10 -o dummy "$1" > $VBR_TEMP 2>&1
	fi
	if [ "$MPG_VERSION" == "1.3.1" ]; then
		mpg123 -n 10 -o dummy "$1" > $VBR_TEMP 2>&1
	fi
	if [ "$MPG_VERSION" == "0.68" ]; then
		mpg123 -n 10 -a /dev/null "$1" > $VBR_TEMP 2>&1
	fi
	if [ "$SOX_VERSION" == "v14.3.0" ]; then
		BITS_OPT=" -b 16 "	
	elif [ "$SOX_VERSION" == "v14.4.1" ]; then
		BITS_OPT=" -b 16 "	
	else
		BITS_OPT=" -w "	
	fi

	TITLE=`cat "$VBR_TEMP" | grep Title: |\
		sed 's/Artist:.*$//' |\
		sed 's/^.*Title:/Title:/' |\
		sed 's/Title:   //' |\
		sed 's/Title:  //' | sed 's/  *$//'`

	ARTIST=`cat "$VBR_TEMP" | grep Artist: |\
		sed 's/Comment:.*$//' |\
		sed 's/^.*Artist:/Artist:/' |\
		sed 's/Artist:  //' |\
		sed 's/Artist: //' | sed 's/  *$//'`

	COMMENT=`cat "$VBR_TEMP" | grep Comment: |\
		sed 's/Album:.*$//' |\
		sed 's/^.*Comment:/Comment:/' |\
		sed 's/Comment: //' |\
		sed 's/Comment://' | sed 's/  *$//'`

	ALBUM=`cat "$VBR_TEMP" | grep Album: |\
		sed 's/Year:.*$//' |
		sed 's/^.*Album:/Album:/' |\
		sed 's/Album:   //' |\
		sed 's/Album:  //' | sed 's/  *$//'`

	YEAR=`cat "$VBR_TEMP" | grep Year: |\
		sed 's/Genre:.*$//' |\
		sed 's/^.*Year:/Year:/' |\
		sed 's/Year:    //' |\
		sed 's/Year:   //' | sed 's/  *$//'`

	GENRE=`cat "$VBR_TEMP" | grep Genre: |\
		sed 's/^.*Genre:/Genre:/' |\
		sed 's/Genre:   //' |\
		sed 's/Genre:  //' | sed 's/  *$//'`

	LGENRE=`lame --genre-list | grep "$GENRE"`
	if [ "$LGENRE" == "" ]; then
		GENRE=Speech
	fi

	BASE=`echo "$1" | sed 's/\.mp3//'`
	#
	# adjust your desired bandwith here. If for instance
	# when playing your input mp3 with mpg123 shows :
	#    MPEG 2.0 layer III, 64 kbit/s, 16000 Hz stereo
	# you would choose twice the displayed kbit rate
	# so 128k, inside the vbr2linear.custom command
	# then select <br> = 128 .
	vbr2linear.custom "$BASE".mp3 0 128 mono
	sox --i "$BASE".wav
	sox -S  "$BASE".wav -r 44.1k -e signed -b 16 "$BASE"44.wav
	sox --i "$BASE"44.wav
	sox -S  "$BASE"44.wav -e signed -b 16 -c 2 "$BASE"44s.wav
	sox --i "$BASE"44s.wav
	#
	# adjust your desired bandwith here.
	# if previously you had 128k above you would select
	# twice that amount, so 256 i.e. inside the lame
	# command : -b 256
	#
	echo " Creating $BASE-stereo.mp3"
	lame    --tt "$TITLE" --ta "$ARTIST"  --tl "$ALBUM" \
		--ty "$YEAR"  --tc "$COMMENT" --tg "$GENRE" \
		-h -b 256 "$BASE"44s.wav "$BASE"-stereo.mp3 
	touch -r "$BASE".mp3 "$BASE"-stereo.mp3
	echo " Done ..."
	rm "$BASE".wav "$BASE"44.wav "$BASE"44s.wav
	rm "$VBR_TEMP"
fi

exit 0