Update gifenc.sh

gifenc.sh

@@ -1,21 +1,95 @@
 #!/bin/sh
 
-if test $# -lt 4; then 
-	cat <<-EOH
-	$0: Script to generate animated gifs easily from command line.
-
-	Usage:
-
-	$0 input.(mp4|avi|webm|flv|...) output.gif horizontal_resolution fps
-	EOH
-    exit 1
+$(ffmpeg --help 2> /dev/null > /dev/null)
+
+if [[ $? -ne 0 ]]; then
+  echo "ffmpeg is required!"
+  exit 1
 fi
 
-palette="$(mktemp /tmp/ffmpeg2gifXXXXXX.png)"
+# default values
+FPS=12
+RESOLUTION=850
+
+# read the options
+TEMP=`getopt -o c:r:f:t:s:d:hl:: --long resolution:,fps:,start:,to:,duration:,help,loop:: -n $0 -- "$@"`
+eval set -- "$TEMP"
+
+# extract options and their arguments into variables.
+while true ; do
+  case "$1" in
+    -h|--help)
+      echo -e "Usage: $0 [options] <input video file> <output gif name>\n"
+      echo "Options:"
+      echo "  -h, --help            Show this help"
+      echo "  -r, --resolution      Set the pixels wide (preserving the aspect ratio)"
+      echo "  -f, --fps             Set the gif frame rate"
+      echo "                          default 12"
+      echo "  -s, --start           Skip the first x seconds"
+      echo "  -t, --to              Capture to x seconds"
+      echo "  -d, --duration        Set the duration"
+      echo "  -l, --loop            Number of times to loop the output"
+      echo "                          default: no loop"
+      echo "                          -l      output loop infinitely"
+      echo "                          -l10    output loop 10 times"
+      echo "Examples:"
+      echo "  $0 input.mp4 out.gif"
+      echo "  $0 input.mp4 out.gif -s"00:01" -d5 -r450"
+      echo "  $0 input.mp4 out.gif -s"20:00" -d5 -l --fps30"
+      exit;;
+    -r|--resolution)
+      case "$2" in
+        "") shift 2 ;;
+        *) RESOLUTION="$2"; shift 2 ;;
+      esac ;;
+    -t|--to)
+      case "$2" in
+        "") shift 2 ;;
+        *) TO="-t $2"; shift 2 ;;
+      esac ;;
+    -l|--loop)
+      case "$2" in
+        "") LOOP="-loop=0" ; shift 2 ;;
+        *) LOOP="-loop=$2" ; shift 2 ;;
+      esac ;;
+    -f|--fps)
+      case "$2" in
+        "") shift 2 ;;
+        *) FPS="$2"; shift 2 ;;
+      esac ;;
+    -s|--start)
+      case "$2" in
+        "") shift 2 ;;
+        *) START="-ss $2"; shift 2 ;;
+      esac ;;
+    -d|--duration)
+      case "$2" in
+        "") shift 2 ;;
+        *) DURATION="-t $2"; shift 2 ;;
+      esac ;;
+    --) shift ; break ;;
+    *) echo "Internal error!" ; exit 1 ;;
+  esac
+done
+
+if [[ "$#" -ne 2  ]]; then
+  echo -e "Usage: $0 [options] <input video file> <output gif name>\n"
+  echo -e "Illegal number of parameters for more informations:\n $0 --help "
+  exit 1
+fi
+
+palette=$(mktemp /tmp/palette_XXXX.png)
+
+filters="fps=$FPS,scale=$RESOLUTION:-1:flags=lanczos"
+
+# echo $filters
+
+# http://blog.pkh.me/p/21-high-quality-gif-with-ffmpeg.html#usage
 
-filters="fps=$4,scale=$3:-1:flags=lanczos"
+# create global color palette
+ffmpeg -v warning $START $TO $DURATION -i "$1" -vf "$filters,palettegen" -y "$palette"
 
-ffmpeg -v warning -i "$1" -vf "$filters,palettegen" -y "$palette"
-ffmpeg -v warning -i "$1" -i $palette -lavfi "$filters [x]; [x][1:v] paletteuse" -y "$2"
+# create GIF
+ffmpeg -v warning $START $TO $DURATION -i "$1" -i "$palette" -lavfi "$filters [x]; [x][1:v] paletteuse" -y "$2"
 
-rm -f "$palette"
+rm $palette