convert_to_gif

#!/bin/bash
# Usage:
# ./convert_to_gif <INPUT> [ffmpeg args]
# e.g. to specify the length of the output: use ffmpeg arg `-t seconds`
# ./convert_to_gif some_long_video.mp4 -t 10

FPS=15
PTS=0.5 # https://trac.ffmpeg.org/wiki/How%20to%20speed%20up%20/%20slow%20down%20a%20video
OUTPUT_WIDTH=400
THREADS=8
INFILE=$1
shift
OUTFILE=${INFILE%.*}.gif
PALETTE=/tmp/palette.$RANDOM.png
ffmpeg "$@" -threads $THREADS -i "$INFILE" -vf setpts=$PTS*PTS,fps=$FPS,scale=$OUTPUT_WIDTH:-1:flags=lanczos,palettegen "$PALETTE"
ffmpeg "$@" -threads $THREADS -i "$INFILE" -i "$PALETTE" \
       -filter_complex "setpts=$PTS*PTS,fps=$FPS,scale=$OUTPUT_WIDTH:-1:flags=lanczos[x];[x][1:v]paletteuse" \
       "$OUTFILE"
rm $PALETTE