Convert a gif to a video for use on the web

gif-to-video.sh

#!/bin/bash

if [[ -z "$1" ]]; then
   echo "provide a path to the source gif file"
   exit 1
elif [ ! -f "$1" ]; then
   echo "the provided path is not a file"
   exit 1
fi

filename=$(basename "$1")
extension="${filename##*.}"

if [[ "$extension" != "gif" ]]; then
   echo "provided path must end in '.gif'"
   exit 1
fi

# mp4 for suitable for safari
# NOTE: both dimensions must be divisible by 2
ffmpeg -f gif -i "$1" -c:v libx264 -movflags +faststart -pix_fmt yuv420p "${1%.*}".mp4

# most other browsers
ffmpeg -f gif -i "$1" "${1%.*}".webm