Generate a dummy video or an image on macOS

dummy

#!/usr/bin/env bash
#
# Generate a dummy video or an image.
#
# The caption text and size (width x height) are drawn on the video or image.
# The countdown timer is drawn in the upper right corner of the video.
#
# This script is intended to be run on macOS.
# And it depends on the following packages.
#   - imagemagick
#   - ffmpeg
# You can install these packages with Homebrew.
#   `brew install imagemagick ffmpeg`
#
# To see the usage, execute `dummy -h`
#

set -euo pipefail

output_image="false"
size="600x600"
caption="Test"
font=""
default_font1="ヒラギノ角ゴシック-W3"
default_font2="Hiragino-Sans-W3"
font_size=""
foreground="white"
background="gray"
image_type="png"
audio_path=""
time="15"
out_dir="$(pwd)"

function show_usage() {
  cat << EOS
usage: dummy [-i, --image | -v, --video]
             [-s, --size <geometry>]
             [-c, --caption <text>]
             [-f, --font <font_name>]
             [--list-fonts]
             [--font-size]
             [--foreground <color>]
             [--background <color>]
             [--image-type <type>]
             [-a, --audio <file>]
             [-t, --time <sencond>]
             [-o, --out <directory>]
             [-h, --help]

options:
  -i, --image             generate an image
  -v, --video             generate a video (default)
  -s, --size <geometry>   specify width and height (default: 600x600)
  -c, --caption <text>    specity caption text (default: Test)
  -f, --font <name>       specify font name (default: "ヒラギノ角ゴシック-W3" or "Hiragino-Sans-W3")
  --list-fonts            list available fonts and exit
  --font-size <number>    specify font point size
                          (default: appropriate value depending on the size)
  --foreground <color>    specify caption text color (default: white)
  --background <color>    specify background color (default: gray)
                          examples of color formats:
                            'lime', '#0f0', '#00ff00', 'rgb(0,255,0)', 'rgb(0,100%,0)'
  --image-type <type>     specify image type (default: png)
  -a, --audio <file>      specify an audio file if you want to merge it with the video
  -t, --time <second>     specify video length in seconds (default: 15)
  -o, --out <directory>   specify output directory (default: working directory)
  -h, --help              show usage and exit
EOS
}

function err() {
  echo "$*" >&2
}

while getopts ivs:c:f:a:t:o:h-: opt; do
  if [[ -n "${OPTARG+x}" ]]; then
    optarg="${OPTARG}"

    if [[ "${opt}" == "-" ]]; then
      opt="-${OPTARG%%=*}"
      optarg="${OPTARG/${OPTARG%%=*}/}"
      optarg="${optarg#=}"

      if [[ -z "${optarg}" ]] && [[ -n "${!OPTIND+x}" ]] && [[ "${!OPTIND}" != -* ]]; then
        optarg="${!OPTIND}"
        shift
      fi
    fi
  fi

  case "-${opt}" in
    -i|--image)
      output_image="true"
      ;;
    -v|--video)
      output_image="false"
      ;;
    -s|--size)
      size="${optarg}"
      ;;
    -c|--caption)
      caption="${optarg}"
      ;;
    -f|--font)
      font="${optarg}"
      ;;
    --list-fonts)
      convert -list font | grep 'Font:' | sed 's/^ *Font: //'
      exit
      ;;
    --font-size)
      font_size="${optarg}"
      ;;
    --foreground)
      foreground="${optarg}"
      ;;
    --background)
      background="${optarg}"
      ;;
    --image-type)
      image_type="${optarg}"
      ;;
    -a|--audio)
      audio_path="${optarg}"
      ;;
    -t|--time)
      time="${optarg}"
      ;;
    -o|--out)
      out_dir=${optarg%/}
      ;;
    -h|--help)
      show_usage
      exit
      ;;
    --)
      break
      ;;
    -\?)
      exit 1
      ;;
    --*)
      err "$0: illegal option -- ${opt##-}"
      exit 1
      ;;
  esac
done
shift $((OPTIND - 1))

if [[ -z "${font}" ]]; then
  found=$(convert -list font | grep 'Font:' | sed 's/^ *Font: //' | grep -E "${default_font1}|${default_font2}")
  if [[ "${found}" == "${default_font1}" ]]; then
    font="${default_font1}"
  elif [[ "${found}" == "${default_font2}" ]]; then
    font="${default_font2}"
  else
    err "Default font not found. Please specify --font option."
    exit 1
  fi
fi

if [[ -z "${font_size}" ]] && [[ "${size}" =~ ^([0-9]+)x([0-9]+)$ ]]; then
  width="${BASH_REMATCH[1]}"
  height="${BASH_REMATCH[2]}"
  if (( height < width )) ; then
    font_size=$((height / 10))
  else
    font_size=$((width / 10))
  fi
fi

escaped_caption="${caption//[:./\\¥*?\"<>|]/_}"
file="${escaped_caption}_${size}"
temp_dir=$(mktemp -d)

if [[ "${output_image}" == "true" ]]; then
  image_path="${out_dir}/${file}.${image_type}"
else
  image_path="${temp_dir}/${file}.${image_type}"
fi

# generate an image
convert \
  -size "${size}" -gravity center \
  -font "${font}" -pointsize "${font_size}" \
  -fill "${foreground}" -background "${background}" \
  caption:"${caption}\n${size}" "${image_path}"

if [[ "${output_image}" == "true" ]]; then
  echo "image generated: ${image_path}"
  exit
fi

video_path="${out_dir}/${file}.mp4"

video_cmd="ffmpeg -y -loglevel error -loop 1 -i '${image_path}' \
 -pix_fmt yuv420p -t ${time} -r 30 '${video_path}' \
 -filter_complex \"drawtext=fontfile=/System/Library/Fonts/Menlo.ttc:text='%{eif\:(${time}*1000+999-t*1000)/1000\:d}':fontcolor=white:fontsize=30:x=w-tw-30:y=30:box=1:boxcolor=black@0.5:boxborderw=10:enable='between(t,0,${time})'\""

if [[ -n "${audio_path}" ]]; then
  video_cmd+=" -stream_loop -1 -i ${audio_path}"
fi

video_cmd+=" < /dev/null"

# generate a video
eval "${video_cmd}"
echo "video generated: ${video_path}"