Make bin/mov2gif more reliable + refactor

bin/mov2gif

@@ -1,14 +1,37 @@
-#!/bin/sh
+#!/usr/bin/env bash
 
-if [ ! -f "$1" ]; then
+usage() { echo "Usage: $0 [-f <fps>] [-o <output-dest>] [-h]"; }
-    >&2 echo "Movie file doesn't exist!"
+
+if [[ $# = 0 ]]; then
+    >&2 echo "No movie file specified"
+    exit
+elif [[ ! -f "$1" ]]; then
+    >&2 echo "$1 does not exist"
     exit
 fi
 
-palette="/tmp/palette.png"
+fps=30
-flags="fps=${4:-10},scale=${3:-640}:-1:flags=lanczos"
+src="$1"
+dest="${$(basename $src)%.mov}.gif"
+while getopts hf:o: opt
+do
+    case "$opt" in
+        -f) fps="$OPTARG" ;;
+        -o) dest="$OPTARG" ;;
+        -h) usage
+            exit
+            ;;
+        :)  >&2 echo "$OPTARG requires an argument"
+            usage
+            exit 1
+            ;;
+    esac
+done
 
-ffmpeg -v warning -i "$1" -vf "$flags,palettegen" -y "$palette"
+palette="$(mktemp)"
-ffmpeg -v warning -i "$1" -i "$palette" -lavfi "$flags [x]; [x][1:v] paletteuse" -y "$2"
+flags="fps=${fps}"
+
+ffmpeg -v warning -i "$src" -vf "$flags,palettegen" -y "$palette"
+ffmpeg -v warning -i "$src" -i "$palette" -lavfi "$flags [x]; [x][1:v] paletteuse" -y "$dest"
 
 [ -f "$palette" ] && rm -f "$palette"