zoompan

#!/bin/sh

#===============================================================================
# zoompan
# ken burns effect
#===============================================================================

# dependencies:
# ffmpeg ffprobe 

#===============================================================================
# script usage
#===============================================================================

# script usage
usage ()
{
# if argument passed to function echo it
[ -z "${1}" ] || echo "! ${1}"
# display help
echo "\
# zoompan, ken burns effect

$(basename "$0") -i input.(png|jpg|jpeg) -d (000) -z (in|out) -p (tl|c|tc|tr|bl|br) -o output.mp4
-i = input.(png|jpg|jpeg)
-d = duration    : from 1-999
-z = zoom        : in or out
-p = position    : zoom to location listed below
-o = outfile.mp4 : optional argument # default is input-name-zoompan-date-time

+------------------------------+
+tl            tc            tr+
+                              +        
+              c               +
+                              +
+bl                          br+
+------------------------------+"
exit 2
}


#===============================================================================
# error messages
#===============================================================================

INVALID_OPT_ERR='Invalid option:'
REQ_ARG_ERR='requires an argument'
WRONG_ARGS_ERR='wrong number of arguments passed to script'
NOT_MEDIA_FILE_ERR='is not a media file'


#===============================================================================
# check the number of arguments passed to the script
#===============================================================================

[ $# -gt 0 ] || usage "${WRONG_ARGS_ERR}"


#===============================================================================
# getopts check the options passed to the script
#===============================================================================

while getopts ':i:d:z:p:o:h' opt
do
  case ${opt} in
     i) infile="${OPTARG}";;
     d) dur="${OPTARG}";;
     z) zoom="${OPTARG}"
        [ "${zoom}" = 'in' ] || [ "${zoom}" = 'out' ];;
     p) position="${OPTARG}";;
     o) outfile="${OPTARG}";;
     h) usage;;
     \?) usage "${INVALID_OPT_ERR} ${OPTARG}" 1>&2;;
     :) usage "${INVALID_OPT_ERR} ${OPTARG} ${REQ_ARG_ERR}" 1>&2;;
  esac
done
shift $((OPTIND-1))


#===============================================================================
# variables
#===============================================================================

# input, input name and extension
infile_nopath="${infile##*/}"
infile_name="${infile_nopath%.*}"

# ffprobe get image height
imgheight="$(ffprobe -v error -select_streams v:0 -show_entries stream=height -of default=nw=1:nk=1 "${infile}")"

# frames per seconds
infps='30'

# zoom in positions

# zoom in top left
zi_top_left="scale=-2:10*ih,\
zoompan=z='min(zoom+0.0015,1.5)':\
fps=${infps}:d=${infps}*${dur},\
scale=-2:${imgheight}" \

# zoom in center
zi_center="scale=-2:10*ih,\
zoompan=z='min(zoom+0.0015,1.5)':\
fps=${infps}:d=${infps}*${dur}:\
x='iw/2-(iw/zoom/2)':\
y='ih/2-(ih/zoom/2)',\
scale=-2:${imgheight}" \

# zoom in top center
zi_top_center="scale=-2:10*ih,\
zoompan=z='min(zoom+0.0015,1.5)':\
fps=${infps}:d=${infps}*${dur}:\
x='iw/2-(iw/zoom/2)',\
scale=-2:${imgheight}" \

# zoom in top right
zi_top_right="scale=-2:10*ih,\
zoompan=z='min(zoom+0.0015,1.5)':\
fps=${infps}:d=${infps}*${dur}:\
x='iw/zoom-(iw/zoom/2)',\
scale=-2:${imgheight}" \

# zoom out positions

# zoom out top left
zo_top_left="scale=-2:2*ih,\
zoompan=z='if(lte(zoom,1.0),1.5,max(1.001,zoom-0.0015))':\
fps=${infps}:d=${infps}*${dur},\
scale=-2:${imgheight}" \

zo_center="scale=-2:2*ih,\
zoompan=z='if(lte(zoom,1.0),1.5,max(1.001,zoom-0.0015))':\
fps=${infps}:d=${infps}*${dur}:\
x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)',\
scale=-2:${imgheight}" \

# zoom out top center
zo_top_center="scale=-2:2*ih,\
zoompan=z='if(lte(zoom,1.0),1.5,max(1.001,zoom-0.0015))':\
fps=${infps}:d=${infps}*${dur}:\
x='iw/2-(iw/zoom/2)',\
scale=-2:${imgheight}" \

# zoom out top right
zo_top_right="scale=-2:2*ih,\
zoompan=z='if(lte(zoom,1.0),1.5,max(1.001,zoom-0.0015))':\
fps=${infps}:d=${infps}*${dur}:\
x='iw/zoom-(iw/zoom/2)',\
scale=-2:${imgheight}" \

# zoom out bottom left
zo_bottom_left="scale=-2:2*ih,\
zoompan=z='if(lte(zoom,1.0),1.5,max(1.001,zoom-0.0015))':\
fps=${infps}:d=${infps}*${dur}:\
y='ih-ih/zoom',\
scale=-2:${imgheight}" \

# zoom out bottom right
zo_bottom_right="scale=-2:2*ih,\
zoompan=z='if(lte(zoom,1.0),1.5,max(1.001,zoom-0.0015))':\
fps=${infps}:d=${infps}*${dur}:\
x='iw-iw/zoom':\
y='ih-ih/zoom',\
scale=-2:${imgheight}" \

# outfile file recording destination
outfile_default="${infile_name}-zoompan-$(date +"%Y-%m-%d-%H-%M-%S").mp4"


#===============================================================================
# function
#===============================================================================

# zoom function
zoom_func () {
  ffmpeg \
  -hide_banner \
  -stats -v panic \
  -r 30 \
  -i "${infile}" \
  -filter_complex \
  "${1}" \
  -y -shortest \
  -c:v libx264 -crf 18 -profile:v high \
  -r 30 -pix_fmt yuv420p \
  -movflags +faststart -f mp4 \
  "${outfile:=${outfile_default}}"
}

# check zoom and position
case "${zoom}" in
    in)
	case "${position}" in
          tl) zoom_func "${zi_top_left}" "${infile}";;
          tc) zoom_func "${zi_top_center}" "${infile}";;
          c) zoom_func "${zi_center}" "${infile}";;
          tr) zoom_func "${zi_top_right}" "${infile}";;
	  *) help;;
	esac
	;;
    out)
	case "${position}" in
          tl) zoom_func "${zo_top_left}" "${infile}";;
          tc) zoom_func "${zo_top_center}" "${infile}";;
          c) zoom_func "${zo_center}" "${infile}";;
          tr) zoom_func "${zo_top_right}" "${infile}";;
          bl) zoom_func "${zo_bottom_left}" "${infile}";;
          br) zoom_func "${zo_bottom_right}" "${infile}";;
	  *) help;;
	esac
	;;
    *) usage "${infile} ${NOT_MEDIA_FILE_ERR}";;
esac