hevconv

#!/usr/bin/env bash

set -euf -o pipefail

#
# Convert to hevc
#

FFMPEG="ffmpeg"
EXTENSION="x265.mp4"


# With -7 switch, commence a new encoding only between these times to save
# energy.  See https://en.wikipedia.org/wiki/Economy_7.
ECONOMY7_START=23
ECONOMY7_END=6



function show_help() {
  cat << EOF

Usage: ${0##*/} [-h] [options] <INFILE> [INFILE...]

Convert videos to hevc using ffmpeg.  The resulting video has .mp4 container &
is renamed to end with ${EXTENSION}.

    -h           display this help and exit
    -b BITRATE   write bitrate <BITRATE>.  Default 500k.  Must end in 'k'.
    -f FRAMERATE re-encode with framerate <FRAMERATE>, in fps
    -7           only begin processing within economy 7 period to save £££
    
<INFILE>  can be any video format supported by your local ffmpeg build

EOF
}


# Set variables...
bitrate="500k"
economy7=''
framerate=''



OPTIND=1 # Reset is necessary if getopts was used previously in the script.  It is a good idea to make this local in a function.
while getopts "hb:f:7" opt; do
    case "$opt" in
        h)
            show_help
            exit 0
            ;;
        b)  bitrate=$OPTARG
            ;;
        f)  framerate=$OPTARG
            ;;
        7)
            economy7=1
            ;;
        '?')
            show_help >&2
            exit 1
            ;;
    esac
done
shift "$((OPTIND-1))" # Shift off the options and optional --.

if [ $# -lt 1 ]; then
	show_help >&2
	exit 1
fi


# Sanity check of econonmy 7 times
if [ $ECONOMY7_START == $ECONOMY7_END ]; then
    echo >&2 "Economy 7 start & end times must be different!"
    exit 1
fi




# Only process with cheap electricity: block until we are within the
# economy 7 period
function sleep_until_economy7() {
	printed=''
	while [ 1 ]; do
		hour=`date -u +%H`
		if [ $ECONOMY7_START -lt $ECONOMY7_END ]; then
			if [ $hour -ge $ECONOMY7_START -a $hour -lt $ECONOMY7_END ]; then
				return # yes
			fi
		else
		    if [ $hour -ge $ECONOMY7_START -o $hour -lt $ECONOMY7_END ]; then
		    	return # yes
		    fi
		fi
		! test $printed && echo -e "Hour $hour not within economy 7 period of $ECONOMY7_START - $ECONOMY7_END; sleeping\n"
		printed='yes'
		sleep 30
	done
}



# Check ffmpeg actually present
type $FFMPEG >/dev/null 2>&1 || { echo >&2 "I require ${FFMPEG} but it's not installed.  Aborting."; exit 1; }


# Quiet: -hide_banner -loglevel error 
# Subtitles: -scodec copy
# Unused -x265-params: no-slow-firstpass
FFMPEG_OPTS="-hide_banner -loglevel fatal -stats -c:a copy -bsf:a aac_adtstoasc -c:v hevc -preset medium -x265-params log-level=error"


if [[ "$framerate" != '' ]]; then
  FRAMERATE_OPT="-r ${framerate}"
else
  FRAMERATE_OPT=""
fi



# Loop through all args
for source in "$@"; do
	test $economy7 && sleep_until_economy7
	dest="${source%.*}.${EXTENSION}"
	echo "Converting $source -> $dest @ ${bitrate}"
	$FFMPEG -y -i "${source}" ${FFMPEG_OPTS} $FRAMERATE_OPT -b:v ${bitrate} -pass 1 -f mp4 /dev/null && \
	$FFMPEG -i    "${source}" ${FFMPEG_OPTS} $FRAMERATE_OPT -b:v ${bitrate} -pass 2 "${dest}"
	rm -f ffmpeg2pass-0.log
	ls -lh "${source}" "${dest}"
done



echo