makegif.sh with FFMPEG - Video to GIF conversion

#!/bin/sh

# You'll have to modify the script if you want to change start_time and duration.
# just remember, the longer the duration the bigger the GIF output. Most sites will only allow 3MB GIFs.

# Here'sa quick little ffmpeg video to GIF converter
# its all so simple, and all you need to do is change
# the format settings if desired for different outputs.

# actually before I can let you get started I just want
# point out what the current options I have chosen are
# just for this little script of mine.

## -t duration (input/output)
## -ss position (input/output) seeks out time where to start at [ minutes - 00:00 | hours - 00:00:00 ]
## -y (global) overwrite output files without asking
## -vf filtergraph (output) create filtergraph specified by filtergrtaph and filter the stream
## -v loglevel
## -gifflags
## +transdiff (transparency support) / -transdiff (non-transparency support)

#
# ok so now that is out the way here is the rest of the script
#


start_time=00:00                  # start time of GIF
duration=5                    # duration of GIF
palette="/tmp/palette.png"            # temporary palette
filters="fps=20,scale=440:-1:flags=lanczos"   # FPS and Scale of GIF

ffmpeg -y -v warning -ss $start_time -t $duration -i $1 -vf "$filters,palettegen"  $palette
ffmpeg -y -v warning -ss $start_time -t $duration  -i $1 -i $palette -lavfi "$filters [x]; [x][1:v] paletteuse=dither=bayer:bayer_scale=1" $2


# you should be able to use the script like so;
#
## $ ./makegif.sh video.mp4 anime.gif
#
# All credits to helping to make this script go to http://blog.pkh.me/p/21-high-quality-gif-with-ffmpeg.html
# additional info for ffmpeg usage at https://www.ffmpeg.org/ffmpeg.html