#!/bin/bash

# $Rev$ $Date$

declare -r VERSION="1.0.1a"
#
# History:
#
# 1.0.1a:
#    * Print output filename
#    * Added manual mode (all timestamps provided by user)
#    * More flexible timestamp format (now e.g. 1h5 is allowed (means 1h 5secs)
#    * BUGFIX: Discard repeated timestamps
#    * Added "set -e". TODO: Add more verbose error messages when called
#      programs fail.
#    * Added basic support for a user configuration file.
#
# 1.0a: (2007-04-10)
#    * First release keeping track of history
#    * Put vcs' url in the signature
#    * Use system username in signature
#    * Added --shoehorn (you get the idea, right?) to feed extra commands to
#      the cappers. Lowelevel and not intended to be used anyway :P
#    * When just a vidcap is requested, take it from the middle of the video
#    * Added -H|--height
#
# 0.99.1a: Interim version, renamed to 1.0a
#
# 0.99a:
#    * Added shadows
#    * More colourful headers
#    * Easier change of colours/fonts
#
# 0.5a: * First usable version
# 0.1:  * First proof of concept

set -e

# Configuration file, please, use this file to modify the behaviour of the
# script. Using this allows overriding some variables (see below)
# to your liking. Only lines with a variable assignment are evaluated,
# it should follow bash syntax, note though that ';' can't be used
# currently in the variable values; e.g.:
#
#	# Sample configuration for vcs
#	user=myname		# Sign all compositions as myname
#	BG_META=gray	# Make the heading gray
#
# The variables that can be overriden are below the block of constants ahead.
declare -r CFGFILE=~/.vcs.conf

# Constants {{{
# see $METHOD
declare -ri METHOD_MPLAYER=1 METHOD_FFMPEG=2
# See $derive_from
declare -ri INTERVAL=1 NUMCAPS=3
# These can't be overriden, modify this line if you feel the need
declare -r PROGRAM_SIGNATURE=<<EOT
with Video Contact Sheet *NIX ${VERSION} <http://p.outlyer.net/vcs/>
EOT

# }}} # End of constants

# Override-able variables {{{

declare -i DEFAULT_INTERVAL=300
declare -i DEFAULT_NUMCAPS=16
# Text before the user name in the signature
declare USER_SIGNATURE="Preview created by"
# By default sign as the system's username
declare user=$(id -un)
# Which of the two methods should be used to guess the number of thumbnails
declare -i derive_from=$INTERVAL
# Which of the two vidcappers should be used (see -F, -M)
# mplayer seems to fail for mpeg or WMV9 files, at least on my system
declare -i METHOD=$METHOD_FFMPEG
# Options used in imagemagick, these options set the final aspect
# of the contact sheet
declare OUTFMT=png            # ImageMagick decides the type from the extension
declare -i OUTPUT_QUALITY=92  # Output image quality (only affects the final
                              # image and obviously only in lossy formats)
# Colours, see convert -list color to get the list
declare BG_META=YellowGreen   # Background for meta info (size, codec...)
declare BG_SIGN=SandyBrown    # Background for signature
declare FG_META=black         # Font colour for meta info box
declare FG_SIGN=black         # Font colour for signature
declare FG_STAMPS=white       # Font colour for timestamps
# Fonts, see convert -list type to get the list
declare FONT_STAMPS=courier   # Used for timestamps behind the thumbnails
declare FONT_META=helvetica   # Used for meta info box
declare FONT_SIGN=$FONT_META  # Used for the signature box
# Font sizes, in points
declare PS_STAMPS=18          # Used for the timestamps
declare PS_META=16            # Used for the meta info box
declare PS_SIGN=11            # Used for the signature
# See --shoehorn
declare shoehorned=

# }}} # End of override-able variables

# Options and other internal usage variables, no need to mess with this!
declare -i interval=$DEFAULT_INTERVAL # Interval of captures (= numsecs / numcaps)
declare -i numcaps=$DEFAULT_NUMCAPS   # Number of captures (= numsecs / interval)
declare title=""
declare -i fromtime=0 # Starting second (see -f)
declare -i totime=-1  # Ending second (see -t)
declare -a initial_stamps=( ) # Stamps added to the calculated ones (see -S)
declare -i th_height= # Height of the thumbnails, by default use same as input
declare -i cols=2     # Number of output columns
declare -i manual_mode=0 # if 1, only command line timestamps will be used

load_config() {
	# These are the variables allowed to be overriden in the config file,
	# please.
	# They're REGEXes, they'll be concatenated to form a regex like
	# (override1|override2|...).
	# Don't mess with this unless you're pretty sure of what you're doing.
	# All this extra complexity is done to avoid including the config
	# file directly for security reasons.
	declare -ra ALLOWED_OVERRIDES=(
		'user'
		'USER_SIGNATURE'
		'BG_.*'
		'FONT_.*'
		'PS_.*'
		'FG_.*'
		'OUTPUT_QUALITY'
		'DEFAULT_INTERVAL'
		'DEFAULT_NUMCAPS'
		'METHOD'
		'OUTFMT'
		'shoehorned'
		'derive_from'
	)

	if [ ! -f "$CFGFILE" ]; then return 0 ; fi

	local compregex=$( sed 's/ /|/g' <<<${ALLOWED_OVERRIDES[*]} )

	while read line ; do # auto variable $line
		# Don't allow ';', FIXME: dunno how secure that really is
		if ! egrep -q '^[[:space:]]*[a-zA-Z_][a-zA-Z0-9_]*=[^;]*' <<<"$line" ; then
			continue
		fi
		if ! egrep -q "^($compregex)=" <<<"$line" ; then
			continue
		fi
		# FIXME: Only print in verbose mose
		# FIXME: Only for really overridden ones
		echo "Overridden variable" $(sed -r 's/^[[:space:]]*([a-zA-Z0-9_]*)=.*/\1/'<<<$line)
		eval $line
	done <$CFGFILE
}

# {{{ # Convenience functions

is_number() {
	egrep -q '^[0-9]+$' <<<"$1"
	return $?
}

# The current code is a tad permissive, it allows e.g. things like
# 10m1h (equivalent to 1h10m)
# 1m1m  (equivalent to 2m)
get_interval() {
	if is_number "$1" ; then echo $1 ; return 0 ; fi

	local s=$(tr '[A-Z]' '[a-z]' <<<"$1")

	# Only allowed characters
	if ! grep -q '[0-9smh]' <<<"$s"; then
		return 1;
	fi

	# FIXME: Find some cleaner way
	local i= c= num= sum=0
	for i in $(seq 0 $(( ${#s} - 1)) ); do
		c=${s:$i:1}
		if is_number $c ; then
			num+=$c
		else
			case $c in
				h) num=$(($num * 3600)) ;;
				m) num=$(($num * 60)) ;;
				s) ;;
				*)
					return 2
				;;
			esac
			sum=$(($sum + $num))
			num=
		fi
	done

	# If last element was a number, it's seconds and they weren't added
	if is_number $c ; then
		sum=$(( $sum + $num ))
	fi

	echo $sum

	return 0
}

pad() {
	local len=$1
	local str=$2

	while [ ${#str} -lt $len ]; do
		str=0$str
	done

	echo $str
}

pretty_stamp() {
	if ! is_number "$1" ; then return 1 ; fi

	local t=$1
	local h=$(( $t / 3600 ))
	t=$(( $t % 3600 ))
	local m=$(( $t / 60 ))
	t=$(( $t % 60 ))
	local s=$t

	local R=""

	if [ $h -gt 0 ]; then
		R+="$h:"
	fi
	R+=$(pad 2 "$m"):$(pad 2 $s)

	echo $R
}

get_pretty_size() {
	local f="$1"

	local bytes=$(du -DL --bytes "$f" | cut -f1)
	local size=""

	if [ "$bytes" -gt $(( 1024**3 )) ]; then
		local gibs=$(( $bytes / 1024**3 ))
		local mibs=$(( ( $bytes % 1024**3 ) / 1024**2 ))
		size="${gibs}.${mibs:0:2} GiB"
	elif [ "$bytes" -gt $(( 1024**2)) ]; then
		local mibs=$(( $bytes / 1024**2 ))
		local kibs=$(( ( $bytes % 1024**2 ) / 1024 ))
		size="${mibs}.${kibs:0:2} MiB"
	elif [ "$bytes" -gt 1024 ]; then
		local kibs=$(( $bytes / 1024 ))
		bytes=$(( $bytes % 1024 ))
		size="${kibs}.${bytes:0:2} KiB"
	else
		size="${bytes} B"
	fi

	echo $size
}

# Rename a file, if the target exists, try with -1, -2, ...
safe_rename() {
	local from="$1"
	local to="$2"

	local ext=$(sed -r 's/.*\.(.*)/\1/g' <<<"$to")

	local n=1
	while [ -f "$to" ]; do
		to="$(basename "$2" .$ext)-$n.$ext"
		n=$(( $n + 1))
	done

	mv "$from" "$to"
	echo "$to" >&2
}

test_programs() {
	for prog in mplayer convert montage ffmpeg ; do
		type -pf "$prog" >/dev/null
		local retval=$?
		if [ $retval -ne 0 ] ; then
			error "Required program $prog not found!"
			return $retval
		fi
	done
}

# Print some text to stderr
error() {
	echo "$1" >&2
}

# }}} # Convenience functions

# {{{ # Core functionality

process() {
	local f=$1

	local numcols=$cols

	if [ ! -f "$f" ]; then
		error "File \"$f\" doesn't exist"
		return 100
	fi
	echo "Processing $f..." >&2

	# Meta data extraction
	# Don't change the -vc as it would affect $vdec
	local mplayer_cache=$(mplayer -benchmark -ao null -vo null -identify -frames 0 -quiet "$f" 2>/dev/null | grep ^ID)
	local vcodec=$(grep ID_VIDEO_FORMAT <<<"$mplayer_cache" | cut -d'=' -f2) # FourCC
	local acodec=$(grep ID_AUDIO_FORMAT <<<"$mplayer_cache" | cut -d'=' -f2)
	local vdec=$(grep ID_VIDEO_CODEC <<<"$mplayer_cache" | cut -d'=' -f2) # Decoder
	local width=$(grep ID_VIDEO_WIDTH <<<"$mplayer_cache" | cut -d'=' -f2)
	local height=$(grep ID_VIDEO_HEIGHT <<<"$mplayer_cache" | cut -d'=' -f2)
	local fps=$(grep ID_VIDEO_FPS <<<"$mplayer_cache" | cut -d'=' -f2)
	# Vidcap/Thumbnail height
	local vidcap_height=$th_height
	if ! is_number "$vidcap_height" || [ "$vidcap_height" -eq 0 ]; then
		vidcap_height=$height
	fi

	local numsecs=$(grep ID_LENGTH <<<"$mplayer_cache"| cut -d'=' -f2 | cut -d. -f1)
	
	if ! is_number $numsecs ; then
		error "Internal error!"
		return 15
	fi

	local nc=$numcaps
	local in=$interval

	# Start bound:
	local startsec=0
	if [ $startsec -lt $fromtime ]; then
		startsec=$fromtime
	fi

	# End bound:
	local endsec=$numsecs
	if [ $totime -ne -1 ] && [ $endsec -gt $totime ]; then
		endsec=$totime
	fi
	
	if [ $startsec -ne 0 ] || [ $endsec -ne $numsecs ]; then
		echo "Restricting to range [$startsec..$endsec]" >&2
	fi

	local delta=$(( $endsec - $startsec ))
	# FIXME: the total # of caps is currently broken when using -f and -t

	# Note that when numcaps mandates the interval is obtained from
	# the actually allowed secods (hence it is not movie_length / numcaps )
	# Adjust interval/numcaps:
	if [ "$derive_from" -eq "$INTERVAL" ]; then
		# Interval rules => it doesn't change
		nc=$(( $delta / $interval ))
		# If a multiple, an extra vidcap is generated (at the last second)
		if [ $(( $delta % $interval )) -eq 0 ]; then
			nc=$(( $nc + 1 ))
		fi
	elif [ "$derive_from" -eq "$NUMCAPS" ]; then
		# Numcaps rules => it doesn't change
		if [ $numcaps -eq 1 ]; then # If just one cap, center it
			in=$(( $numsecs / 2 ))
		else
			in=$(( $numsecs / $numcaps ))
		fi
	else
		error "Internal error!"
		return 145
	fi

	# Let's try to make some sense...
	# Minimum interval allowance:
	if [ $in -gt $numsecs ]; then
		error "The interval is longer than the video length."
		error "Use a lower interval or numcaps instead."
		error "Skipping \"$f\"."
		return 16
	fi
	# Contact sheet minimum cols:
	if [ $nc -lt $numcols ]; then
		numcols=$nc
	fi

	# Tempdir

	local dir=$(mktemp -d -p . vcs.XXXXXX)
	if [ "$?" -ne 0 ]; then
		error "Error creating temporary directory"
		return 17
	fi

	local n=

	# Get the stamps (if in auto mode)...

	local stamps=( )
	if [ $manual_mode -ne 1 ]; then

		n=$(( $startsec + $in ))
		stamps=( ${initial_stamps[*]} $n )

		while [ $n -le $endsec ]; do
			n=$(( $n + $in ))
			if [ $n -gt $endsec ]; then break; fi

			stamps=( ${stamps[*]} $n )
		done
	else
		stamps=( ${initial_stamps[*]} )
	fi

	n=1
	local p=""
	local cap=""
	local montage_command="montage -font $FONT_STAMPS -pointsize $PS_STAMPS \
	                       -gravity SouthEast -fill white "
	local output=$(tempfile --prefix "vcs-" --suffix '-preview.png' -d .)

	# Let's reorder the stamps, this away user-added stamps get their correct
	# position also remove duplicates. Note AFAIK sort only sorts lines, that's
	# why y replace spaces by newlines.
	#
	# Note that stamps keeps being an array and stamps[1..N] still hold their
	# old values, although it's treated as a string after this
	stamps=$( sed 's/ /\n/g' <<<"${stamps[*]}" | sort -n | uniq )

	local VIDCAPFILE=00000001.png

	# If the temporal vidcap already exists, abort
	if [ -f $VIDCAPFILE ]; then
		error "Temporal vidcap file ($VIDCAPFILE) exists, remove it before running!."
		exit 134
	fi

	local NUMSTAMPS=$(wc -w <<<"$stamps")
	# TODO: Aspect ratio
	for stamp in $stamps; do
		# Note that it must be checked against numsecs and not endsec, to allow
		# the user manually setting stamps beyond the boundaries
		if [ $stamp -gt $numsecs ]; then continue; fi

		echo "Generating capture #${n}/${NUMSTAMPS}..." >&2

		if [ $METHOD -eq $METHOD_MPLAYER ]; then
			mplayer -sws 9 -ao null -benchmark -vo "png:z=0" -quiet \
				-frames 1 -ss $stamp $shoehorned "$f" >/dev/null 2>&1
		elif [ $METHOD -eq $METHOD_FFMPEG ]; then
			ffmpeg -y -ss $stamp -i "$f" -an -dframes 1 -vframes 1 -vcodec png \
				-f rawvideo $shoehorned $VIDCAPFILE >/dev/null 2>&1
		else
			error "Internal error!"
			return 142
		fi || {
			error "The capturing program failed!"
			return 143
		}

		p=$(pad 6 $stamp).png
#		mv 00000001.png $dir/$p
		n=$(( $n + 1 ))

		cap=$dir/$p
		# Add the timestamp to each vidcap, doing it hear is much powerful/simple
		# than with the next montage command
		convert -box '#000000aa' \
				-fill $FG_STAMPS -pointsize $PS_STAMPS -gravity SouthEast \
				-stroke none -strokewidth 3 -annotate +5+5 " $(pretty_stamp $stamp) " \
				$VIDCAPFILE "$cap"

		montage_command+=" $cap"
	done
	rm -f $VIDCAPFILE

	# geometry affects the source images, not the target one!
	# Note the file name could also be added by using the "-title" option, but I reserved
	# it for used set titles
	montage_command+=" -geometry x${vidcap_height}+10+5 -tile ${numcols}x -shadow"
	if [ "$title" ]; then
		montage_command+=" -font $FONT_META -fill $FG_META -title '$title'"
	fi
	montage_command+=" $output"

	echo "Composing contact sheet..." >&2
	eval $montage_command # eval is required to evaluate correctly the text in quotes!
	mv "$output" . 2>/dev/null || true

	# Codec "prettyfication"
	case $( tr '[A-Z]' '[a-z]' <<<$vcodec) in
		xvid) vcodec=Xvid ;;
		dx50) vcodec="DivX 5" ;;
		0x10000001) vcodec="MPEG-1" ;;
		0x10000002) vcodec="MPEG-2" ;;
		avc1) vcodec="MPEG-4 AVC" ;;
		wmv2) vcodec="WMV 8" ;; # WMV2 is v8
	esac
	if [ "$vdec" == "ffodivx" ]; then
		vcodec+=" (MPEG-4)"
	elif [ "$vdec" == "ffh264" ]; then
		vcodec+=" (h.264)"
	fi

	case $( tr '[A-Z]' '[a-z]' <<<$acodec ) in
		85) acodec='MPEG-1 Layer III (MP3)' ;;
		80) acodec='MPEG-1 Layer II (MP2)' ;;
		mp4a) acodec='MPEG-4 AAC' ;;
		353) acodec='WMA 2' ;;
		"") acodec="no audio" ;;
	esac


	local meta="Filename: $f
File size: $(get_pretty_size "$f")
Length: $(pretty_stamp "$numsecs")"
	local meta2="Dimensions: ${width}x${height}
Format: $vcodec / $acodec
FPS: $fps"
	local signature="$USER_SIGNATURE $user
$PROGRAM_SIGNATURE"

	# Now let's add meta info
	# This one enlarges the image to add the text, and puts
	# meta info in two columns
	convert -font $FONT_META -pointsize $PS_META \
		-background $BG_META -fill $FG_META -splice 0x$(( $PS_META * 4 )) \
		-gravity NorthWest -draw "text 10,10 '$meta'" \
		-gravity NorthEast -draw "text 10,10 '$meta2'" \
		"$output" "$output"
	# Finishing touch, signature

	convert -gravity South -font $FONT_SIGN -pointsize $PS_SIGN \
		-background $BG_SIGN -splice 0x34+0-0 \
		-fill $FG_SIGN -draw "text 10,3 '$signature'" "$output" "$output"
	rm -rf $dir/

	if [ $OUTFMT != "png" ]; then
		local newout="$(basename "$output" .png).$OUTFMT"
		convert -quality $OUTPUT_QUALITY "$output" "$newout"
		rm "$output"
		output="$newout"
	fi
	
	echo -n "Output wrote to " >&2
	safe_rename "$output" "$(basename "$f").$OUTFMT"
}

show_help() {
    local P=$(basename $0)
	cat <<EOF
Video Contact Sheet *NIX v${VERSION}, (c) 2007 Toni Corvera

Usage: $P [options] <file>

Options:
  -i|--interval <arg>   Set the interval to arg. An optional unit can be
                        used (case-insensitive) , e.g.:
                            Seconds:      90
                            Minutes:      3m
                            Hours:        1h
                        Use either -i or -n.
  -n|--numcaps <arg>    Set the number of captured images to arg. Use either
                        -i or -n.
  -f|--from <arg>       Set starting time. No caps before this. Same format
                        as -i.
  -t|--to <arg>         Set ending time. No caps beyond this. Same format
                        as -i.
  -T|--title <arg>      Add a title above the vidcaps.
  -u|--user <arg>       Set the username found in the signature to this.
  -S|--stamp <arg>      Add the image found at the timestamp "arg", same format
                        as -i.
  -m|--manual           Manual mode: Only timestamps indicated by the user are
                        used (use in conjunction with -S), when using this
                        -i and -n are ignored.
  -H|--height <arg>     Set the output (individual thumbnail) height. Width is
                        derived accordingly. Note width cannot be manually set.
  -j|--jpeg             Output in jpeg (by default output is in png).
  -h|--help             Show this text.

  Options used for debugging purposes or to tweak the internal workings:
  -M|--mplayer          Force the usage of mplayer.
  -F|--ffmpeg           Force the usage of ffmpeg.
  --shoehorn <arg>      Pass "arg" to mplayer/ffmpeg. You probably don't need it.

Examples:
    Create a contact sheet with default values (vidcaps at intervals of
    $DEFAULT_INTERVAL seconds), the resulting file will be called
    input.avi.png:
        \$ $P input.avi

    Create a sheet with vidcaps at intervals of 3 minutes:
        \$ $P -i 3m input.avi

    Create a sheet with vidcaps starting at 3 mins and ending at 18 mins,
    add an extra vidcap at 2m and another one at 19m:
        \$ $P -f 3m -t 18m -S2m -S 19m input.avi

Quirks:
    Currently MPEG handling seems to be broken.

EOF
}

# }}} # Core functionality

# Test requirements
test_programs || exit 54

load_config

# {{{ # Command line parsing

# Based on getopt-parse.bash example.
# On debian systems see </usr/share/doc/util-linux/examples/getopt-parse.bash.gz>

# FIXME: use username / no name at all with -u noarg, and not -u
TEMP=$(getopt -o i:n:u:T:f:t:S:jhFMH:c:m \
       --long "interval:,numcaps:,username:,title:,from:,to:,stamp:,jpeg,help,shoehorn:,mplayer,ffmpeg,height:,columns:,manual" \
       -n $0 -- "$@")

eval set -- "$TEMP"

while true ; do
	case "$1" in
		-i|--interval)
			if ! interval=$(get_interval "$2") ; then
				error "Interval must be a number (given $2)"
				exit 68
			fi
			if [ "$interval" -le 0 ]; then
				error "Interval must be higher than 0, set to the default $DEFAULT_INTERVAL"
				interval=$DEFAULT_INTERVAL
			fi
			derive_from=$INTERVAL
			shift # Option arg
			;;
		-n|--numcaps)
			if ! is_number "$2" ; then
				error "Number of caps must be a number! (given $2)"
				exit 68
			fi
			numcaps="$2"
			derive_from=$NUMCAPS
			shift # Option arg
			;;
		-u|--username) user="$2" ; shift ;;
		-T|--title) title="$2" ; shift ;;
		-f|--from)
			if ! fromtime=$(get_interval "$2") ; then
				error "Starting timestamp must be a valid interval"
				exit 68
			fi
			shift
			;;
		-t|--to)
			if ! totime=$(get_interval "$2") ; then
				error "Ending timestamp must be a valid interval"
				exit 68
			fi
			if [ "$totime" -eq 0 ]; then
				error "Ending timestamp was set to 0, set to movie length"
				totime=-1
			fi
			shift
			;;
		-S|--stamp)
			if ! temp=$(get_interval "$2") ; then
				error "Timestamps must be a valid interval"
				exit 68
			fi
			initial_stamps=( ${initial_stamps[*]} $temp )
			shift
			;;
		-j|--jpeg) OUTFMT=jpg ;;
		-h|--help) show_help ; exit 0 ;;
		--shoehorn)
			shoehorned="$2"
			shift
			;;
		-F) METHOD=$METHOD_FFMPEG ;;
		-M) METHOD=$METHOD_MPLAYER ;;
		-H|--height)
			if ! is_number "$2" ; then
				error "Height must be a number (given $2)"
				exit 68
			fi
			th_height="$2"
			shift
			;;
		-c|--columns)
			if ! is_number "$2" ; then
				error "Columns must be a number (given $2)"
				exit 68
			fi
			cols="$2"
			shift
			;;
		-m|--manual) manual_mode=1 ;;
		--) shift ; break ;;
		*) error "Internal error! (remaining opts: $@)" ; exit 76 ;
	esac
	shift
done

# Remaining arguments
if [ ! "$1" ]; then
	show_help
	exit 67
fi
# If -m is used then -S must be used
if [ $manual_mode -eq 1 ] && [ -z $initial_stamps ]; then
	error "You must provide timestamps (-S) when using manual mode (-m)"
	exit 68
fi

for arg do process "$arg" ; done

# }}} # Command line parsing


# vim:set ts=4 ai: #