slider now takes text and has many nice options

.local/bin/slider

@@ -6,26 +6,76 @@
 #
 # Imagemagick and ffmpeg required.
 
-# TODO:
+# Application cache if not stated elsewhere.
-#  - add the ability to include text, using imagemagick text to image feature.
+cache="${XDG_CACHE_HOME:-$HOME/.cache}/slider"
 
+while getopts "hvrpi:c:a:o:d:f:t:e:x:" o; do case "${o}" in
+	c) bgc="$OPTARG" ;;
+	t) fgc="$OPTARG" ;;
+	i) file="$OPTARG" ;;
+	a) audio="$OPTARG" ;;
+	o) outfile="$OPTARG" ;;
+	d) prepdir="$OPTARG" ;;
+	r) redo="$OPTARG" ;;
+	s) ppt="$OPTARG" ;;
+	e) endtime="$OPTARG" ;;
+	x) res="$OPTARG"
+		echo "$res" | grep -qv "^[0-9]\+x[0-9]\+$" &&
+			echo "Resolution must be dimensions separated by a 'x': 1280x720, etc." &&
+			exit 1 ;;
+	p) echo "Purge old build files in $cache? [y/N]"
+		read -r confirm
+		echo "$confirm" | grep -iq "^y$" && rm -rf "$cache" && echo "Done."
+		exit ;;
+	v) verbose=True ;;
+	*) echo "$(basename "$0") usage:
+  -i  input timecode list (required)
+  -a  audio file
+  -c  color of background (use html names, black is default)
+  -t  text color for text slides (white is default)
+  -s  text font size for text slides (150 is default)
+  -o  output video file
+  -e  if no audio given, the time in seconds that the last slide will be shown (5 is default)
+  -x  resolution (1920x1080 is default)
+  -d  tmp directory
+  -r  rerun imagemagick commands even if done previously (in case files or background has changed)
+  -p  purge old build files instead of running
+  -v  be verbose" && exit 1
 
-[ -z "$1" ] && echo "Usage:
+esac done
-	first arg:	file with timecodes
-	second arg:	audio file (optional)" && exit 1
 
-prepdir="$1-src"
+# Check that the input file looks like it should.
-prepfile="$prepdir/$1.prep"
+{ head -n 1 "$file" 2>/dev/null | grep -q "^00:00:00	" ;} || {
-outfile="$1.mp4"
+	echo "Give an input file with -i." &&
+	echo "The file should look as this example:
 
-totaldur="$(ffmpeg -i "$2" 2>&1 | awk '/Duration/ {print $2}' | sed s/,//)"
+00:00:00	first_image.jpg
-totseconds="$(date '+%s' -d "$totaldur")"
+00:00:03	otherdirectory/next_image.jpg
+00:00:09	this_image_starts_at_9_seconds.jpg
+etc...
 
+Timecodes and filenames must be separated by Tabs." &&
+	exit 1
+	}
+
+if [ -n "${audio+x}" ]; then
+	# Check that the audio file looks like an actual audio file.
+	case "$(file --dereference --brief --mime-type -- "$audio")" in
+		audio/*) ;;
+		*) echo "That doesn't look like an audio file."; exit 1 ;;
+	esac
+	totseconds="$(date '+%s' -d $(ffmpeg -i "$audio" 2>&1 | awk '/Duration/ {print $2}' | sed s/,//))"
+	endtime="$((totseconds-seconds))"
+fi
+
+prepdir="${prepdir:-$cache/$file}"
+outfile="${outfile:-$file.mp4}"
+prepfile="$prepdir/$file.prep"
+
+[ -n "${verbose+x}" ] && echo "Preparing images... May take a while depending on the number of files."
 mkdir -p "$prepdir"
 
-echo "Preparing images... May take a while depending on the number of files."
 {
-
 while read -r x;
 do
 	# Get the time from the first column.
@@ -34,14 +84,20 @@ do
 	# Duration is not used on the first looped item.
 	duration="$((seconds - prevseconds))"
 
-	# Get the filename from the rest.
+	# Get the filename/text content from the rest.
-	filename="${x#*	}"
+	content="${x#*	}"
-	base="$(basename "$filename")"
+	base="$(basename "$content")"
 	base="${base%.*}.jpg"
 
-	# Resize and read the image file, but not if already done.
+	if [ -f "$content" ]; then
-	[ ! -f "$prepdir/$base" ] &&
+		# If images have already been made in a previous run, do not recreate
-		convert -size 1920x1080 canvas:black -gravity center "$filename" -resize 1920x1080 -composite "$prepdir/$base"
+		# them unless -r was given.
+		{ [ ! -f "$prepdir/$base" ] || [ -n "${redo+x}" ] ;} &&
+			convert -size "${res:-1920x1080}" canvas:"${bgc:-black}" -gravity center "$content" -resize 1920x1080 -composite "$prepdir/$base"
+	else
+		{ [ ! -f "$prepdir/$base" ] || [ -n "${redo+x}" ] ;} &&
+			convert -size "${res:-1920x1080}" -background "${bgc-black}" -fill "${fgc:-white}" -pointsize "${ppt:-150}" -gravity center label:"$content" "$prepdir/$base"
+	fi
 
 	# If the first line, do not write yet.
 	[ "$time" = "00:00:00" ] || echo "file '$prevbase'
@@ -51,17 +107,16 @@ duration $duration"
 	prevbase="$base"
 	prevtime="$time"
 	prevseconds="$(date '+%s' -d "$prevtime")"
-done < "$1"
+done < "$file"
 # Do last file which must be given twice as follows
 echo "file '$base'
-duration $((totseconds-seconds))
+duration ${endtime:-5}
 file '$base'"
 } > "$prepfile"
-
+if [ -n "${audio+x}" ]; then
-if [ -f "$2" ]; then
+	ffmpeg -hide_banner -y -f concat -safe 0 -i "$prepfile" -i "$audio" -c:a aac -vsync vfr -c:v libx264 -pix_fmt yuv420p "$outfile"
-	ffmpeg -y -f concat -safe 0 -i "$prepfile" -i "$2" -c:a aac -vsync vfr -c:v libx264 -pix_fmt yuv420p "$outfile"
 else
-	ffmpeg -y -f concat -safe 0 -i "$prepfile" -vsync vfr -c:v libx264 -pix_fmt yuv420p "$outfile"
+	ffmpeg -hide_banner -y -f concat -safe 0 -i "$prepfile" -vsync vfr -c:v libx264 -pix_fmt yuv420p "$outfile"
 fi
 
 # Might also try: