#!/bin/bash
#
# Apply zoom-pan effect to a still image to create a video
#
# Usage:
#
#    jkenburns [-n|--no-exec] in-file out-file duration [zoom] [x] [y] [start] [end] [fps] [width] [height]
#
# -n or --no-exec : if set, do not execute ffmpeg but print what would have run
# in-file         : file to trim
# out-file        : write scaled file here
# duration        : how long the output video will be
# zoom            : zoom factor, default is 1 (no zoom)
# x               : zoom focus X point, default is center
# y               : zoom focus Y point, default is center
# start           : when to start zooming, default is beginning of video
# end             : when to end zooming, default is end of video
# fps             : frame per second for output video, default is 25
# width           : output width, default is in-file width
# height          : output height, default is in-file height
#
SCRIPT="${0}"
SCRIPT_DIR="$(cd "$(dirname "${SCRIPT}")" && pwd)"
. "${SCRIPT_DIR}"/jvc_common

IN_FILE="${1?no in-file provided}"
OUT_FILE="${2?no out-file provided}"
DURATION="${3:?no duration provided}"
ZOOM="${4}"
X_POS="${5}"
Y_POS="${6}"
T_START="${7}"
T_END="${8}"
FRAMES_PER_SEC="${9}"
WIDTH="${10}"
HEIGHT="${11}"

echo "
{
  \"assets\": [
    { \"name\": \"input\", \"path\": \"${IN_FILE}\" }
  ],
  \"operations\": [
    {
      \"operation\": \"ken-burns\",
      \"creates\": {
        \"name\": \"zoompan\",
        \"dest\": \"${OUT_FILE}\"
      },
      \"source\": \"input\",
      \"duration\": \"${DURATION}\"$(if [[ -n "${ZOOM}" ]] ; then echo ",
      \"zoom\": \"${ZOOM}\""; fi)$(if [[ -n "${X_POS}" ]] ; then echo ",
      \"x\": \"${X_POS}\""; fi)$(if [[ -n "${Y_POS}" ]] ; then echo ",
      \"y\": \"${Y_POS}\""; fi)$(if [[ -n "${T_START}" ]] ; then echo ",
      \"start\": \"${T_START}\""; fi)$(if [[ -n "${T_END}" ]] ; then echo ",
      \"end\": \"${T_END}\""; fi)$(if [[ -n "${FRAMES_PER_SEC}" ]] ; then echo ",
      \"fps\": \"${FRAMES_PER_SEC}\""; fi)$(if [[ -n "${WIDTH}" ]] ; then echo ",
      \"width\": \"${WIDTH}\""; fi)$(if [[ -n "${HEIGHT}" ]] ; then echo ",
      \"height\": \"${HEIGHT}\""; fi)
    }
  ]
}
" | "${SCRIPT_DIR}"/jvc ${JVC_OPTIONS}