From ef8412899b99c5ac8d84cc1d1d3116ac1298eac7 Mon Sep 17 00:00:00 2001
From: Jordan Husney <jordan.husney@gmail.com>
Date: Thu, 13 Oct 2016 11:50:03 -0400
Subject: [PATCH] Fixes #1 and #2

---
 ffmpeg2gif.sh | 56 ++++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 42 insertions(+), 14 deletions(-)

diff --git a/ffmpeg2gif.sh b/ffmpeg2gif.sh
index 4d77287..8a84d1b 100755
--- a/ffmpeg2gif.sh
+++ b/ffmpeg2gif.sh
@@ -20,9 +20,9 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 
-VERSION=0.2.0
+VERSION=0.3.0
 SUBJECT=ffmpeg2gif
-USAGE="Usage: ffmpeg2gif.sh -hv -f <framerate> -y <yscale> input.mov output.gif"
+USAGE="Usage: ffmpeg2gif.sh [-hv -f <framerate> -y <yscale> -s <skip_sec> -t <duration_sec>] input.mov output.gif"
 
 # --- Options processing -------------------------------------------
 if [ $# == 0 ] ; then
@@ -32,8 +32,10 @@ fi
 
 framerate=30
 yscale=480
+skip_sec=-1
+duration_sec=-1
 
-while getopts ":f:y:vh" optname
+while getopts ":f:y:s:t:vh" optname
   do
     case "$optname" in
       "v")
@@ -56,6 +58,22 @@ while getopts ":f:y:vh" optname
             echo "invalid yscale \"$OPTARG\"" && exit 1
         fi
         ;;
+      "s")
+        if [[ "$OPTARG" =~ ^[0-9]+$ ]] && [ "$OPTARG" -ge 1 ]; then
+            echo "skip_sec: $OPTARG"
+            skip_sec=$OPTARG
+        else
+            echo "invalid skip_sec \"$OPTARG\"" && exit 1
+        fi
+        ;;
+      "t")
+        if [[ "$OPTARG" =~ ^[0-9]+$ ]] && [ "$OPTARG" -ge 1 ]; then
+            echo "duration_sec: $OPTARG"
+            duration_sec=$OPTARG
+        else
+            echo "invalid duration_sec \"$OPTARG\"" && exit 1
+        fi
+        ;;
       "h")
         echo $USAGE
         exit 0;
@@ -80,24 +98,34 @@ shift $(($OPTIND - 1))
 inputfile=$1
 outputfile=$2
 
-[[ -z $inputfile ]] && echo "no input file specified" && exit -1
-[[ -z $outputfile ]] && echo "no output file specified" && exit -1
+[[ -z "$inputfile" ]] && echo "no input file specified" && exit -1
+[[ -z "$outputfile" ]] && echo "no output file specified" && exit -1
 
 # --- Body --------------------------------------------------------
 #  SCRIPT LOGIC GOES HERE
-echo "input file: $inputfile"
-echo "output file: $outputfile"
+echo "input file: \"$inputfile\""
+echo "output file: \"$outputfile\""
 palettefile=$(mktemp /tmp/$SUBJECT.XXXXXX).png
 filters="fps=$framerate,scale=$yscale:-1:flags=lanczos"
 
-ffmpeg -v warning -i $1 -vf "$filters,palettegen" -y $palettefile &&
-    ffmpeg -v warning -i $inputfile -i $palettefile \
-      -lavfi "$filters [x]; [x][1:v] paletteuse" -y $outputfile
+optional_params=""
+if [ "$skip_sec" -ge 1 ]; then
+  optional_params="-ss $skip_sec"
+fi
+if [ "$duration_sec" -ge 1 ]; then
+  optional_params="$optional_params -t $duration_sec"
+fi
+
+ffmpeg $optional_params -v warning \
+  -i "$inputfile" -vf "$filters,palettegen" -y "$palettefile" &&
+  ffmpeg $optional_params -v warning -i "$inputfile" -i "$palettefile" \
+    -lavfi "$filters [x]; [x][1:v] paletteuse" -y "$outputfile"
 
-if [ -f $outputfile ]; then
-    outputsize=`du -h $outputfile | cut -f1`
-    echo "$outputfile is $outputsize"
+if [ -f "$outputfile" ]; then
+    outputsize=`du -h "$outputfile" | cut -f1`
+    echo "\"$outputfile\" is $outputsize"
 fi
 
-rm "$palettefile"
+rm "$palettefile" 2> /dev/null
+exit 0
 # -----------------------------------------------------------------