Generate a slideshow from jpg's with audio

generate-slideshow.sh

#!/bin/bash
set -euo pipefail
IFS=$'\n\t'

DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
DOCKER_WORKDIR="/slideshow"
WORKDIR="work"

# Parameters
AUDIO_FILE="music.mp3"
DIM="800x800" # Slideshow dimensions
PICS_DIR="pics"

# Create the work dir
mkdir -p "${DIR}/${WORKDIR}"

# Copy over all images so we don't mess with the originals
x=1
for i in $DIR/$PICS_DIR/*jpg; do
  counter=$(printf %03d $x)
  cp "$i" "${DIR}/${WORKDIR}/img${counter}.jpg"
  x=$((x+1))
done

# Make sure no one side of an image is larger than 600px
docker run -ti --rm \
           -v "${DIR}:${DOCKER_WORKDIR}" \
           -w "${DOCKER_WORKDIR}" \
           -u "$(id -u):$(id -g)" \
           --net=none --log-driver none \
           v4tech/imagemagick \
           mogrify \
           -resize "${DIM}" \
           -gravity center \
           -extent "${DIM}" \
           -background "rgb(0,0,0)" \
           $WORKDIR/*.jpg

# Generate the slideshow along with the audio
docker run -ti --rm \
           -v "${DIR}:${DOCKER_WORKDIR}" \
           -w "${DOCKER_WORKDIR}" \
           -u "$(id -u):$(id -g)" \
           --net=none --log-driver none \
           jrottenberg/ffmpeg:4.0-scratch -y \
           -framerate 1 \
           -i "${WORKDIR}/img%03d.jpg" \
           -i "${AUDIO_FILE}" \
           -shortest \
           -c:a copy "${WORKDIR}/slideshow.mp4"