#!/bin/bash

# As far as I know ripping streaming radio is legal.  Nevertheless, you use
# this script at your own risk.

# http://lwn.net/Articles/182954/

# --- check user args ---------------------------------------------------------
if [ x"$1" = x"" ]; then
	echo 'please specify an output file (mp3)'
	exit 1
else 
	outfile=$1
fi

if [ x"$2" = x"" ]; then
	echo 'please specify a URL'
	exit 2
else 
	url=$2
fi

if [ x"$3" = x"" ]; then
	echo 'please specify a recording duration (sec)'
	exit 3
else 
	dur=$[ $3+2 ]
fi




# mplayer without video
MPLAYER="mplayer -quiet -cache 32 -nojoystick -nolirc -prefer-ipv4 -noframedrop -vc null -vo null "

# lame, recommended noise shaping, vbr default quality with max256kbps, output every 10min
#LAME="lame --vbr-new -V 4 -B 256 --nohist --disptime 600 -h --tc \"ripped: `date +\%m-\%d-\%Y`\""
LAME="lame -h --vbr-new -V 4 --nohist --disptime 600"
#LAME="lame -h -b 128 --nohist --disptime 600"


## settings below are optimized for voice encoding
#lame -S -a -m m --ty "$YEAR" --vbr-new -V 9 --lowpass 13.4 --athaa-sensitivity 1 \
#    --resample 32 $TEMPFILE-silenced.wav $FILE.mp3 >/dev/null &
#sox $TEMPFILE.wav -c 1 $TEMPFILE-silenced.wav silence 1 0.2 0.5% -1 0.2 0.5% >/dev/null&


checktime=10



# --- create a named pipes ----------------------------------------------------
tmpdir=`mktemp -td pipesXXXXX` || exit 4
wavpipe="$tmpdir/wavpipe"
#soxpipe="$tmpdir/soxpipe"
mkfifo $wavpipe || exit 5
#mkfifo $soxpipe || exit 6


# --- attach and execute ------------------------------------------------------
# invoke lame sourcing wave pipe and detach
echo "$LAME $wavpipe \"$outfile\" 2>&1 &"
$LAME $wavpipe "$outfile" 2>&1 &
#$LAME $soxpipe "$outfile" 2>&1 &

# invoke sox, sourcing the wave pipe and sinking the sox pipe and detach
#sox $wavpipe $soxpipe silence 1 1 0.2 0.5% -1 0.2 0.5% >/dev/null &

dur=$((dur - checktime))

until
	# start ripping, sinking to streaming pipe as a detached process so we can
	# begin countdown to TERM
	echo "$MPLAYER -ao pcm:fast:file=\"$wavpipe\" -playlist \"$url\" 2>&1"
	$MPLAYER -ao pcm:fast:file="$wavpipe" -playlist "$url" 2>&1 &

	mypid=$!
	# in case of SIGINT and SIGTERM: kill bg process before exit
	trap 'kill $mypid; exit 7;' 2 15
	sleep $checktime
	# check if process is still here, i.e. the stream is being downloaded,
	# or if the recording length is reached 
	kill -0 $mypid >/dev/null 2>&1 || [ $dur -le 0 ]
do
  echo "Server problem, another try: $(date '+%Y%m%d %H%M%S')" 
  # decrease recording length by checktime; in the case of a transient
  # problem the remaining length of the stream will be saved
  dur=$((dur - checktime))
  # retry download with another until loop
done


if [ $dur -gt 0 ]; then 
	# wait recording length
	sleep $dur
	# kill bg process and wait for its termination
	kill $mypid 
	wait
else
	# the recording length had been reached by trying just to get the download
	# started.  an unrecoverable problem prevented the desired download
	echo "Aborted." 
fi

# remove pipes
rm -fr $tmpdir