#!/bin/bash
#
# tvtc 0.1
#
# Copyright (c) 2009, Christophe Osuna
# All rights reserved.
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
# 
#     * Redistributions of source code must retain the above copyright
#       notice, this list of conditions and the following disclaimer.
#     * Redistributions in binary form must reproduce the above copyright
#       notice, this list of conditions and the following disclaimer in the
#       documentation and/or other materials provided with the distribution.
#     * The names of its contributors may not be used to endorse or promote 
#       products derived from this software without specific prior written 
#       permission.
#
# THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND ANY
# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE REGENTS AND CONTRIBUTORS BE LIABLE FOR ANY
# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
# This script allows Neuf Cegetel clients to play and record some TV channels.
# It requires MPlayer to be installed.
#
# User doc: http://osuna.org/christophe/projets/tvtc
# Developer doc below configuration section

# -----------------------------------------------------------------------------
# Configuration

# Path to mplayer executable
mplayer=/usr/bin/mplayer

# Stream cache size in Kib (should be greater than 128)
cachesize=1024

# Temporary file to download ASX file
asxtmp=/tmp/tvtc.asx

# Temporary file to save PID
pidfile=/tmp/tvtc.pid

# Directory to save intermediate record file
tmpdir=/tmp

# Date format used when naming files - man date (1) for more details
namebeg=%F-%H%M
nameend=%H%M

# Channels (from http://televisionsurpc.neuf.fr/televisionsurpc.m3u)
# Last update: jan 7th 2009
channels=(
 "france2" "France 2" "http://80.118.196.219/webtv-asx.cgi?channel=france_2"
 "france3" "France 3" "http://80.118.196.219/webtv-asx.cgi?channel=france_3"
 "france5" "France 5" "http://80.118.196.219/webtv-asx.cgi?channel=france_5"
 "arte" "Arte" "http://80.118.196.219/webtv-asx.cgi?channel=arte"
 "direct8" "Direct 8" "http://80.118.196.219/webtv-asx.cgi?channel=direct_8"
 "nt1" "NT1" "http://80.118.196.219/webtv-asx.cgi?channel=nt1"
 "nrj12" "NRJ 12" "http://80.118.196.219/webtv-asx.cgi?channel=nrj12"
 "lcp" "La chaine parlementaire" "http://80.118.196.219/webtv-asx.cgi?channel=lcp"
 "france4" "France 4" "http://80.118.196.219/webtv-asx.cgi?channel=france_4"
 "bfm" "BFM TV" "http://80.118.196.219/webtv-asx.cgi?channel=bfm_tv"
 "tv5" "TV5" "http://80.118.196.219/webtv-asx.cgi?channel=tv5_monde"
 "franceo" "France O" "http://80.118.196.219/webtv-asx.cgi?channel=france_o"
 "euronews" "Euronews" "http://80.118.196.219/webtv-asx.cgi?channel=euronews"
 "aljazeera" "Aljazeera" "http://80.118.196.219/webtv-asx.cgi?channel=aljazeera"
 "liberty" "Liberty TV" "http://80.118.196.219/webtv-asx.cgi?channel=liberty_tv"
 "beur" "Beur TV" "http://80.118.196.219/webtv-asx.cgi?channel=beur_tv"
 "nrj" "NRJ Hits" "http://80.118.196.219/webtv-asx.cgi?channel=nrj_hits"
 "video_click" "Video Click" "http://80.118.196.219/webtv-asx.cgi?channel=video_click"
 "kto" "KTO" "http://80.118.196.219/webtv-asx.cgi?channel=kto"
)

# Set to something to show debug messages
DEBUG=

# You shouldn't have to configure anything below
# -----------------------------------------------------------------------------

# Information for developers
#
# Neuf Cegetel streams its webtv channels using a playlist [1]. Each element in
# the playlist points to an ASX file, which contains a set of servers to stream
# a channel. So what this scripts does is simply download the ASX file, choose
# a random server and let MPlayer play or record the stream.
#
# When the user wants to record a channel, this script runs MPlayer and
# expects it to be killed either by the user (^C) or by the script itself
# (stoprec command).
#
# [1] http://televisionsurpc.neuf.fr/televisionsurpc.m3u

PATH=/bin:/usr/bin

mplayeropts="-cache $cachesize -really-quiet"
name=
url=

# TODO: do this with getopt
case $3 in
    -ws)
	mplayeropts="$mplayeropts -aspect 16/9"
	;;
    -z)
	mplayeropts="$mplayeropts -vf crop=320:176:0:34"
	;;
esac

# Print a debug message
# $1 message
function debug()
{
    if [ x$DEBUG != x ]; then echo $1 ; fi
}

# Print help screen
function usage()
{
    echo "Usage: $0 COMMAND {CHANNEL} [OPTION]"
    echo ""
    echo "COMMAND can be one among:"
    echo " list          list channels"
    echo " rec CHANNEL   start recording channel"
    echo " stoprec       stop a recording"
    echo " view CHANNEL  view channel"
    echo ""
    echo "OPTIONS:"
    echo " -ws  force widescreen format"
    echo " -z   zoom"
}

# List available channels
function list()
{
    echo -e "Short name\tLong name"
    echo -e "----------\t---------"
    for ((i=0 ; i<${#channels[@]} ; i+=3)); do
	echo -e "${channels[i]}\t\t${channels[$((i+1))]}"
    done
}

# Update "name" and "url" global variables when a new short name is given
# $1 channel short name
function updateNameAndURL()
{
    local i
    local maxsrv
    local line

    if [ x$1 = x ] ; then usage; exit 1; fi

    name=
    url=
    for ((i=0 ; i<${#channels[@]} ; i+=3)); do
	if [ "${channels[$i]}" = "$1" ]; then
	    name=${channels[$((i+1))]}
	    url=${channels[$((i+2))]}
	fi
    done

    if [ "$url" = "" ]; then
	echo "Invalid channel. Aborting."
	exit 1
    fi

    debug "ASX URL: $url"
    wget --quiet --output-document=$asxtmp $url
    if [ $? != 0 ]; then
	echo "Unable to download ASX file ($url). Aborting.";
	exit 1;
    fi
    # Extract URL from <REF href="..." /> in a random line
    maxsrv=$(grep "<REF href=" $asxtmp | wc -l)
    line=$(($RANDOM % $maxsrv + 1))
    url=$(grep "<REF href=" $asxtmp | sed -n "${line}s/.*href=\"\\(.*\\)\".*/\\1/p")
    rm -f $asxtmp
    debug "Stream URL: $url"
}

# Record a channel into a file
# $1 channel short name
function record()
{
    updateNameAndURL $1
    echo "Recording ${name}..."
    datebeg=$(date +$namebeg)
    # This will block until mplayer receives a SIGTERM signal and will
    # result in a "stream.dump" file being created.
    cd $tmpdir
    echo $$ > $pidfile
    $mplayer $mplayeropts -nocache -dumpstream $url
    rm -f $pidfile
    dateend=$(date +$nameend)
    cd -
    mv $tmpdir/stream.dump "${1}-${datebeg}-${dateend}.avi"
}

# Stop a recording
#
# MPlayer (the process wich parent's PID is stored in $pidfile) is
# killed.
function stoprecord()
{
    local pid
    local ppid
    ppid=$(cat $pidfile)
    if [ "$ppid" = "" ]; then
	echo "No recording to stop. Aborting."
	exit 1
    fi
    kill $(ps -e -o ppid,pid | awk "/^ *$ppid/ {print \$2}")
}

# Open mplayer to view a channel
# $1 channel short name
function view()
{
    updateNameAndURL $1
    echo "Playing ${name}..."
    debug "$mplayer $mplayeropts $url"
    $mplayer $mplayeropts $url
}

case $1 in
    list)
	list
	;;
    -h|--help)
	usage
	;;
    rec)
	record $2
	;;
    stoprec)
	stoprecord
	;;
    view)
	view $2
	;;
    *)
	usage
	exit 1
	;;
esac