#!/usr/bin/env bash

# prep - Encode for streaming and schedule cron job
# Usage:  prep
#   Called by cron every minute; process oldest .upload file in /var/www/uploadpage/streams)

log=/var/www/encoding.log
dir=/var/www/uploadpage/streams

# Check for oldest uploaded file
upload=$(/usr/bin/ls -1tr "$dir"/*.upload 2>/dev/null |head -1)

# Finished if no /var/www/uploadpage/streams/*.upload files found
[[ $upload ]] || exit 0

Log(){ # 1:message 2:returncode
	echo "$1">>"$log"
	# Remove source (if returncode not zero)
	/usr/bin/sync
	/usr/bin/sleep 1
	(($2)) && /usr/bin/rm "$file"
	exit $2
}

# Rename upload and check type
file=${upload%.upload} name=${file##*/} key=${name%%.*} date=${name##*.} video=$file.mp4
/usr/bin/mv "$upload" "$file"

type=$(file -bL --mime-type "$file")
[[ ! ${type:0:5} = video ]] && Log "File $name is of type $type" 1

# Encode video
## Single pass
#/usr/bin/ffmpeg -y -i "$file" -c:v libx264 -x264opts no-scenecut -b:v 6M -force_key_frames 'expr:gte(t,n_forced*2)' -c:a copy -tune zerolatency -f mp4 "$video" ||
# Double pass
/usr/bin/ffmpeg -y -i "$file" -c:v libx264 -x264opts no-scenecut -b:v 6M -force_key_frames 'expr:gte(t,n_forced*2)' -movflags faststart -c:a copy -tune zerolatency -pass 1 -f mp4 "$video" &&
	/usr/bin/ffmpeg -y -i "$file" -c:v libx264 -x264opts no-scenecut -b:v 6M -force_key_frames 'expr:gte(t,n_forced*2)' -movflags faststart -c:a copy -tune zerolatency -pass 2 -f mp4 "$video" ||
	Log "Error encoding $name" 2

# Schedule cron job
m=${date:14:2} m=${m#0} h=${date:11:2} h=${h#0}
D=${date:8:2} D=${D#0} M=${date:5:2} M=${M#0}
/usr/bin/crontab -l ||
	echo -e "# m h dom mon dow  command\n" |/usr/bin/crontab -
line="$m $h $D $M "'*'"  /var/www/stream '${video##*/}'"
echo -e "$(/usr/bin/crontab -l)\n$line" |/usr/bin/crontab -

Log "crontab:  '$line'" 0