#!/bin/bash
# Look into HW video encoding to vp9 instead of h264:
# https://www.reddit.com/r/VP9/comments/g9uzzv/hardware_encoding_vp9_on_intel/

video_detect() {
  for file in "${*}"; do
    INFO=($(ffprobe -v error \
      -select_streams v:0 \
      -show_entries stream=codec_name:format=format_name \
      -of default=noprint_wrappers=1:nokey=1 "${file}"))
    if (( ${#INFO[*]} != 2 )); then
      echo "${file}|none|none"
    else
      echo "${file}|${INFO[0]}|${INFO[1]}"
    fi
  done
}

# mstodate MILLISECONDS
#
# Given MILLISECONDS, convert to DAYS:HOURS:MINUTES:SECONDS.MS
mstodate() {
  scales=( "86400-d:" "3600-h:-02" "60-m:-02" "1-.-02" )
  echo $1 | sed -E 's/([[:digit:]]{3})$/ \1/' | while read sec msec; do
    for scale in ${scales[@]}; do
      parts=(${scale//-/ })
      divisor=${parts[0]}
      suffix=${parts[1]}
      min=${parts[2]}
      num_scale=$((sec / divisor))
      sec=$((sec - (num_scale * divisor)))
      printf "%${min}d%s" ${num_scale} ${suffix}
    done
    echo "${msec}s"
  done
}

function move {
  base="$(dirname "${IN}")"
  [ ! -d "${base}" ] && continue
  base=/remote/media/backup/"${base}"
  [ ! -d "${base}" ] && mkdir -p "${base}"
  [ -e "${base}" ] && mv "${IN}" "${base}"/
}

function convert {
  IN="$1"
  SRC_CODEC="$2"
  FORMAT="$3"
  OUT="${IN/%.???/.mkv}"
  ORIG=${OUT}
  if [[ "${OUT}" == "${IN}" ]]; then
    OUT=${OUT/.mkv/.transcoded.mkv}
    [ -e "${OUT}" ] && rm "${OUT}"
  else
    [ -e "${OUT}" ] && move && return 0
    [ -e /remote/media/backup/"${OUT}" ] && return 0
  fi

  TITLE="${IN%.*}"
  TITLE="${TITLE##*/}"
  if [[ "${SRC_CODEC}" == "h264" ]]; then
    echo "Content will have format changed from ${FORMAT}/h264 to mkv/h264."
    # Just change container to matroska
    input_flags="
    "
    output_flags="
      -c copy
    "
  else
    echo "Content will be transcoded from ${FORMAT}/${SRC_CODEC} to mkv/h264."
    # Convert all video streams to h264. Copy all other streams unchanged (audio, subtitle, etc.)
    # Move headers to start of the file for fast start
    # Use "reasonable" quality level of 20, slow encode
    #
   input_flags="
     -hwaccel qsv
     -c:v hevc_qsv
   "
   output_flags="
     -c copy
     -vf vpp_qsv=format=nv12
     -c:v h264_qsv
     -global_quality 25
   "
  fi

  echo -n "Counting frames in ${IN}: "
  FRAMES=$(ffprobe -v error -select_streams v:0 -count_packets -show_entries stream=nb_read_packets -of csv=p=0 "${IN}")
  echo "${FRAMES} frames."

  # Use stdbuf to flush stdout/stderr every line
  STARTTIME=$(date +%s)
  LASTTIME=${STARTTIME}
  LASTPOS=0
  IN=$(realpath "${IN}")
  OUT=$(realpath "${OUT}")
  DIN=$(dirname "${IN}")
  DOUT=$(dirname "${OUT}")
  NO_COLOR=1 \
    docker run --user=1000 --device=/dev/dri \
    --rm \
    -v "${DIN}:${DIN}" \
    -v "${DOUT}:${DOUT}" \
    intel-media-ffmpeg \
    ffmpeg \
      -nostdin \
      -v quiet \
      -loglevel fatal \
    ${input_flags} \
      -i "${IN}" \
      -progress /dev/stdout \
      -metadata title="${TITLE/.\//}" \
    ${output_flags} \
      -movflags +faststart \
    "${OUT}" \
      -y | while read line; do
      POS=$(echo $line | sed -n 's/^frame=*\(.*\)/\1/p')
      if [[ "${POS}" != "" ]]; then
        NOW=$(date +%s)
        ELAPSEDTIME=$(( NOW - LASTTIME ))
        if (( ELAPSEDTIME > 5 )); then
          ELAPSEDFRAMES=$(( POS - LASTPOS ))
          REMAININGFRAMES=$(( FRAMES - POS ))
          REMAININGFRAMES=$(( REMAININGFRAMES * 1000 )) # convert to ms
          FRAMERATE=$(( ELAPSEDFRAMES / ELAPSEDTIME ))
          if (( FRAMERATE != 0 )); then
            REMAININGMS=$(( REMAININGFRAMES / FRAMERATE ))
            printf "\r%*s\r%s" $(tput cols) " " "Processing for $(mstodate $(( NOW - STARTTIME ))000). Processing at ($((ELAPSEDFRAMES / ELAPSEDTIME ))fps). Now at frame $POS of $FRAMES $(( $(( 100 * POS)) / FRAMES ))%. Estimating $(mstodate ${REMAININGMS}) remaining."
          else
            printf "\r%*s\r%s" $(tput cols) " " "Processing for $(mstodate $(( NOW - STARTTIME ))000). Processing at ($((ELAPSEDFRAMES / ELAPSEDTIME ))fps). Now at frame $POS of $FRAMES $(( $(( 100 * POS)) / FRAMES ))%. No frames processed in last ${ELAPSEDTIME} seconds."
          fi
          LASTTIME=${NOW}
          LASTPOS=${POS}
        fi
      fi
    done && move && {
      if [[ "${ORIG}" == "${IN}" ]]; then
        # If the original file was an '.mkv' then OUT was '.transcoded.mkv'
        # during transcode. Now that the transcode is complete, set the
        # file back to the original name.
        mv "${OUT}" "${IN}"
      fi
    }
    NOW=$(date +%s)
    echo -e "\nCompleted in $(mstodate $(( NOW - STARTTIME ))000)"
#    -vcodec copy \
#    -acodec aac \
}

function check_and_convert {
  video_detect "$1" | while read entry; do
    #                     # file:codec:format
    file="${entry%%|*}"   # file
    entry="${entry#*|}"   # codec:format
    codec="${entry%%|*}"  # codec
    format="${entry##*|}" # format
    codec="${codec,,}"
    if [[ "${codec}" == "none" ]]; then
      continue
    fi
    if [[ "${codec}" == "h264" ]] && [[ "${format}" =~ mkv|matroska ]]; then
      # If container is not mkv, convert to mkv container
      echo "Skipping ${file} as it is already mkv/h264."
    else
      convert "${file}" "${codec}" "${format}"
    fi
  done
}

if [ -z "$1" ]; then
  find . -type f \
    -and -not -path "./backup/*" | sort | while read file; do
    check_and_convert "${file}"
  done
else
  for file in "$*"; do
    check_and_convert "${file}"
  done
fi