#!/bin/sh

# Join video files (Nautilus)
# Copyright (C) Richard H. Tingstad
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# See <http://www.gnu.org/licenses/>.

# File names used to determine order
# f2.mpg, f1.mpg, ... => f1-joined.mpg

# Version 0.1.0
# Depends on zenity and mencoder (and mplayer)

title="Join"
if [ $# -lt 2 ]
then
	zenity --title="$title" --error --text="You must select at least two files."
	exit 1
fi
files=`echo "$NAUTILUS_SCRIPT_SELECTED_FILE_PATHS" | egrep -v '^$' | sort`
echo "$files" | while read f
do
	if [ ! -f "$f" ]
	then
		zenity --title="$title" --error --text="'$f' is not a file."
		exit 1
	fi
done
firstfile=`echo "$files" | head -n 1`
extension=`echo "$firstfile" | egrep -oi '\.[a-z0-9]+$'`
basename=`basename "$firstfile" $extension`
outfile="$basename-joined$extension"
if [ -e "$outfile" ]
then
	if ! zenity --title="$title" --question --text="File '$outfile' exists, will overwrite. Continue?"
	then
		exit 1
	fi
fi
info=`mplayer -identify -frames 0 -vc null -vo null -ao null "$firstfile"`
demux=`echo "$info" |egrep 'ID_DEMUXER'|cut -d '=' -f2`
video=`echo "$info" |egrep 'ID_VIDEO_FORMAT'|cut -d '=' -f2`
audio=`echo "$info" |egrep 'ID_AUDIO_FORMAT'|cut -d '=' -f2`
for f in "$@"
do
	if ! mplayer -identify -frames 0 -vc null -vo null -ao null "$f"|egrep -q "ID_VIDEO_FORMAT=$video"
	then
		if zenity --title="$title" --question --text="Files may have different video encodings. Try anyway?"
		then
			break
		else
			exit 1
		fi
	fi
done
params=""
case "$demux" in
"mpegps")
	format="mpeg"
	params="$params -noskip -mc 0"
;;
"lavfpref" | "asf")
	format="lavf"
;;
*)
	format="avi"
;;
esac
case "$video" in
"0x10000001"|"mpg1")
	params="$params -mpegopts format=mpeg1"
;;
esac
case "$audio" in #http://www.mplayerhq.hu/DOCS/codecs-status.html
"MP4A"|"mp4a"|"AAC"|"AACP"|"racp"|"raac"|"VLB")
	params="$params -fafmttag 0x00ff"
;;
esac
arg=`echo "$files" | awk '{ printf "\"%s\" ", $0 }'`
ok=false
eval "mencoder -forceidx -of $format$params -oac copy -ovc copy -o \"$outfile\" $arg && ok=true"
if $ok
then
	zenity --title="$title" --info --text="All done."
else
	zenity --title="$title" --error --text="An error occurred."
fi