#!/bin/bash

PARAM=$0
# Strip path from command name
PARAM=${PARAM##*/}

short() {
  echo "Transcode AVC (H.264) to HEVC (H.265) with 5Mbps using VBR"
}

help() {
cat << EOF
$(short)

$(info)

IN_FILE   AVC (H.264) format input stream
OUT_FILE  HEVC (H.265) output stream

NOTE: Above paths are read from the container volume /data.

EOF
}

details() {
cat << EOF
$(short)

This script provides a quick reference example using the following
ffmpeg command:

  ffmpeg \
    -loglevel debug \
    -hwaccel qsv \
    -qsv_device \${QSV_DEVICE:-/dev/dri/renderD128} \
    -c:v h264_qsv \
    -i /data/"\${IN_FILE}" \
    -c:v hevc_qsv \
    -b:v 5M \
    -y \
    /data/"\${OUT_FILE}"

EOF
}

arguments=()

for arg in $*; do
  [[ $arg =~ ^-- ]] && {
    command=${arg/--}
    case $command in
    short) short
        exit 0
	;;
    help) help
        exit 0
	;;
    details) details
        exit 0
        ;;
    *) echo "Unrecognized command."
	exit 1
	;;
    esac
  } || {
    arguments+=("$arg")
  }
done

info() {
  cat << EOF
usage: $PARAM INPUT-FILE OUTPUT-FILE
EOF
}

QSV_DEVICE=${QSV_DEVICE:-/dev/dri/renderD128}

[ "${arguments[0]}" == "" ] || [ "${arguments[1]}" == "" ] && {
  info
  exit 1
}

[ ! -e /data/"${arguments[0]}" ] && {
  cat << EOF
Error: '${arguments[0]}' not found.

Was the volume /data mounted when launching the container?

    docker ... --volume \$(pwd)/data:/data ...

or similar?

EOF

  exit 1
}

[ ! -e ${QSV_DEVICE} ] && {
cat << EOF

Error: '${QSV_DEVICE}' not found.

Did you pass /dev/dri to Docker?

    docker ... --device=/dev/dri ...

or similar?

EOF
  exit 2
}

IN_FILE="${arguments[0]}"
OUT_FILE="${arguments[1]}"

  ffmpeg \
    -loglevel debug \
    -hwaccel qsv \
    -qsv_device ${QSV_DEVICE:-/dev/dri/renderD128} \
    -c:v h264_qsv \
    -i /data/"${IN_FILE}" \
    -c:v hevc_qsv \
    -b:v 5M \
    -y \
    /data/"${OUT_FILE}"