Transcode_subfolders.sh

#!/bin/bash

# stop if error occurs
set -e

Help()
{
   # Display Help
   echo "Depending on the resolution, selects crf and preset"
   echo "Predefined for quality, but if something is mediocre, then CRF-23 medium for 720p-1080p should be specified manually"
   echo "CRF-22 slow on 1080p 24-series gives ~9 gigs, CRF-23 medium gives ~5 gigs"
   echo
   echo "Syntax: $0 [-r]"
   echo "$0 -r"
   echo "options:"
   echo "r     remove source"
   echo 
   echo "Folder name tags (don't work for subfolders):"
   echo "[P-%%] [CRF-%%] [force] [skip]"
   echo ""
   echo "[to720] - downscale to 720p"
   echo "[anime] or [film] - encoding preset params (default anime)"
   echo ""		 
   echo "[opus] - convert audio to opus"
   echo "[surround] - enable convert surround audio to opus"
   echo "[kbps-%%] - default opus bitrate"
   echo "[rl-%%,%%] - remove selected lang tags from audio tracks"
   echo "[-flac] force convert FLAC to Opus (ignored opus and surround flags)"
   echo
   exit
}

del=false
surround=false

# [ $# -eq 0 ] && Help # if no parameters, will show help

while getopts "r" o; do
	case "${o}" in
		r)
			del=true
			;;
		\?) # incorrect option
			echo "Error: Invalid option"
			Help
			;;
	esac
done

# removes n strings from the positional parameters list. Thus shift $((OPTIND-1)) removes all the options that have been parsed by getopts from the
# parameters list, and so after that point, $1 will refer to the first non-option argument passed to the script.
shift $((OPTIND-1))

log_file=`date +"%Y%m%dT%H%M"`
[ ! -d "./logs" ] && mkdir ./logs
touch ./logs/$log_file.log
touch ./logs/${log_file}_problems.log
exec &> >(tee -a "./logs/$log_file.log")

function log_err() {
 echo "$1" | tee -a ./logs/${log_file}_problems.log
}

function fnDelete {
	if [ -f "$1" ]; then 
		if [[ "$del" == "true" ]]; then
			rm "$1"
			echo "$1 is removed"
		fi
	fi
}

opus=false
flac_to_opus=false
remove_langs=()
audio_bitrate="96" 

function BitrateForChannelLayout()
{
        local channel_layout="$1"
        local source_bitrate="$2"
		local source_codec="$3"		
		local force_s="$4"	
		
		if [[ "$source_codec" =~ "opus" ]]; then
			echo "N/A" # skip track
			return
		fi 

        if [[ "$channel_layout" =~ "7.1" && ($surround == "true" || $force_s == "true") ]]; then
			if [[ $audio_bitrate -gt 96 ]]; then
				echo $((96*5))
			else
				echo $(($audio_bitrate*5))
			fi
        elif [[ "$channel_layout" =~ "5.1" && ($surround == "true" || $force_s == "true") ]]; then
			if [[ $audio_bitrate -gt 96 ]]; then
				echo $((96*3))
			else
				echo $(($audio_bitrate*3))
			fi
        elif [ "$channel_layout" == "stereo" ]; then
                if [[ $source_bitrate =~ ^[0-9]+$ && $source_bitrate -gt 160 && $audio_bitrate -lt 128 ]]; then
                        echo $(($audio_bitrate+32))
                else
                        echo "$audio_bitrate"
                fi
        else
                echo "N/A"
        fi
}


function GenerateMapAudio()
{
	local input_file="$1"
	local to_opus="$2"
	local flac_convert="$3"
	local command=""

	local audio_streams=$(ffprobe -v error -select_streams a -show_entries stream=index -of csv=p=0 "$input_file")
	local lang_tags=( $(ffprobe -v quiet -select_streams a -show_entries stream_tags=language -of csv=p=0 "$input_file") )
	local audio_index=-1
	local codec_index=-1
	
	for audio_stream in $audio_streams; do
		audio_index=$(($audio_index + 1))
		codec_index=$(($codec_index + 1))
		local map_option="-map 0:a:$audio_index"
		local codec_option="-c:a:$codec_index copy"
		local channel_layout=$(ffprobe -v error -select_streams a:$audio_index -show_entries stream=channel_layout -of default=noprint_wrappers=1:nokey=1 "$input_file")
		local source_bitrate=$(ffprobe -v error -select_streams a:$audio_index -show_entries stream=bit_rate -of default=noprint_wrappers=1:nokey=1 "$input_file")
		if [[ "$source_bitrate" =~ ^[0-9]+$ ]]; then
			source_bitrate=$(($source_bitrate / 1000))
		fi
		local source_codec=$(ffprobe -v quiet -select_streams a:$audio_index -show_entries stream=codec_name -of csv="p=0" "$input_file")

		# Check if language is to be removed
		local language=${lang_tags[$audio_index]}
		if [[ ! ${#remove_langs[@]} -eq 0 && -n $language && " ${remove_langs[@]} " =~ " $language " ]]; then
			codec_index=$(($codec_index - 1))
			continue
		fi

		# Add bitrate and format options based on channel layout
		local bitrate=$(BitrateForChannelLayout "$channel_layout" "$source_bitrate" "$source_codec")
		
		if [[ "$bitrate" != "N/A" ]] && [[ "$to_opus" == "true" ]]; then 
			codec_option="-c:a:$codec_index libopus -b:a:$codec_index ${bitrate}k -filter:a:$codec_index \"aformat=channel_layouts='7.1|5.1|stereo'\""
		fi
		
		if [[ "$source_codec" == "flac" ]] && [[ "$flac_convert" == "true" ]]; then 
			local bitrate=$(BitrateForChannelLayout "$channel_layout" "160" "$source_codec" "true")
			codec_option="-c:a:$codec_index libopus -b:a:$codec_index ${bitrate}k -filter:a:$codec_index \"aformat=channel_layouts='7.1|5.1|stereo'\""
		fi

		# Add current audio map and codec to command
		command+=" $map_option $codec_option"
	done

	# Add subtitle streams to command
	command+=" -map 0:s? -c:s copy -map 0:t? -c:t copy -map 0:d? -c:d copy -map -0:d:m:handler_name:\"SubtitleHandler\""

	echo "$command"
}

crf_overwrite=""
preset_overwrite=""
skip=false
force=false
to720=false
preset_params=""

shopt -s globstar
for i in ./**/*; do
  echo "ITER = $i"
  ext=${i##*.}
 
 
 	if [[ -d "$i" ]]; then
		preset_params=""
	
		if [[ "$i" == *"[CRF-"* ]]; then
		  crf_number=$(echo "$i" | grep -oP "\[CRF-\K\d+" | head -1)
		  if [[ -n "$crf_number" ]]; then
			crf_overwrite="$crf_number"
		  else
			crf_overwrite=""  # default value
		  fi
		else
		  crf_overwrite=""  # default value
		fi

		regex="\[P-(\S+)\]"
		if [[ "$i" =~ $regex ]]; then
		  if [[ -n "${BASH_REMATCH[1]}" ]]; then
			preset_overwrite="${BASH_REMATCH[1]}"
		  else
			preset_overwrite=""  # default value
		  fi
		else
		  preset_overwrite=""  # default value
		fi
	
		if [[ "$i" == *"[skip]"* ]]; then
		  skip=true
		  echo "THIS FOLDER WILL BE SKIPPED (folder tag)"
		else
		  skip=false
		fi
		
		if [[ "$i" == *"[force]"* ]]; then
		  force=true
		  echo "THIS FOLDER WILL BE FORCE-CONVERTED (folder tag)"
		else
		  force=false
		fi		
		
		if [[ "$i" == *"[to720]"* ]]; then
		  to720=true
		  echo "THIS FOLDER WILL BE DOWNSCALLED TO 720 (folder tag)"
		else
		  to720=false
		fi	
		
		if [[ "$i" == *"[film]"* ]]; then
		  preset_params="film"
		  echo "THIS FOLDER WILL CONVERT WITH FILM PARAMS (folder tag)"
		fi	

		if [[ "$i" == *"[anime]"* ]]; then
		  preset_params="anime"
		  echo "THIS FOLDER WILL CONVERT WITH ANIME PARAMS (folder tag)"
		fi	
		
		if [[ "$i" == *"[opus]"* ]]; then
		  opus=true
		  echo "THIS FOLDER WILL CONVERT TO OPUS (folder tag)"
		  
			if [[ "$i" == *"[surround]"* ]]; then
			  surround=true
			  echo "surround audio will be converted to opus (folder tag)"
			else
			  surround=false
			fi	
		  
		else
		  opus=false
		fi

		if [[ "$i" == *"[-flac]"* ]]; then
		  flac_to_opus=true
		  echo "THIS FOLDER WILL CONVERT FLAC TO OPUS (folder tag)"
		else
		  flac_to_opus=false
		fi		
		
		if [[ "$i" == *"[kbps-"* ]]; then
		  audio_bitrate_number=$(echo "$i" | grep -oP "\[kbps-\K\d+" | head -1)
		  if [[ -n "$audio_bitrate_number" ]]; then
			audio_bitrate="$audio_bitrate_number"
		  else
			audio_bitrate="96"  #  default value
		  fi
		else
		  audio_bitrate="96"  #  default value
		fi

		regex="\[rl-(\S+)\]" # put the regex in a variable because some patterns won't work if included literally
		if [[ "$i" =~ $regex ]]; then
		  if [[ -n "${BASH_REMATCH[1]}" ]]; then
			IFS=',' read -r -a remove_langs <<< "${BASH_REMATCH[1]}"
		  else
			remove_langs=()   #  default value
		  fi
		else
		  remove_langs=()   #  default value
		fi
		
	fi
 
 
  if [ "$ext" == "MP4" -o "$ext" == "mp4" -o "$ext" == "avi" -o "$ext" == "mkv" ]; then
  	if [[ "$i" == *"_k."* ]] || [ -f "${i%.*}_k.mkv" ]; then
		echo "File found! Skip";
		continue
	fi
	
	
	if [[ "$skip" == "true" ]]; then
		continue
	fi
	
	  if [ -f "$i" ]; then 
	    height=`ffprobe -v error -select_streams v:0 -show_entries stream=height -of csv=s=x:p=0 "$i" | cut -d 'x' -f 1`
		codec=`ffprobe -v error -select_streams v:0 -show_entries stream=codec_name -of default=noprint_wrappers=1:nokey=1 "$i"`
		
		if [[ "$codec" == "h265" ]] || [[ "$codec" == "hevc" ]] || [[ "$codec" == "av1" ]] || [[ "$codec" == "vp9" ]]; then
			if [[ "$force" == "false" ]]; then
				echo "Already used hign compressed codec: $codec! Skip";
				continue
			fi		
		fi
		
		SCALE=()
		
		if [[ "$to720" == "true" ]] && [[ $height -gt 720 ]]; then
			height=720
			SCALE=("-filter:v:0" "zscale=-2:720:filter=spline36")
		fi
		
		if [[ "$preset_params" == "" ]]; then
			preset_params="anime"
			echo "Will use default preset (anime)"
		fi
		
		params=""
		
		case $preset_params in
			film)
				echo "Film preset params."
				
				params="no-sao=1:aq-mode=2"
				crf="25"
				preset="medium"

				if [[ $height -lt 1190 ]]; then
					params="strong-intra-smoothing=0:no-sao=1:aq-mode=3"
					crf="23"		
					preset="medium"
				fi	
				if [[ $height -lt 721 ]]; then
					params="strong-intra-smoothing=0:limit-sao=1:aq-mode=3"
					crf="23"
					preset="slow"			
				fi
				if [[ $height -lt 481 ]]; then
					params="strong-intra-smoothing=0:limit-sao=1:aq-mode=3"
					crf="22"
					preset="slow"			
				fi
				
				;;
			anime)
				echo "Anime preset params."
				
				params="no-sao=1:tskip=1:psy-rd=1.5:psy-rdoq=1:ref=4:aq-mode=3"
				crf="24"
				preset="medium"
						
				if [[ $height -lt 1081 ]]; then
					params="no-sao=1:tskip=1:psy-rd=1.5:psy-rdoq=1:ref=4:aq-mode=3"
					crf="22"
					preset="medium"			
				fi
				if [[ $height -lt 721 ]]; then
					params="no-sao=1:tskip=1:psy-rd=1.5:psy-rdoq=1:ref=5:aq-mode=3"
					crf="21"
					preset="slow"			
				fi
				if [[ $height -lt 481 ]]; then
					params="limit-sao=1:tskip=1:psy-rd=1.5:psy-rdoq=1:ref=5:aq-mode=3"
					crf="20"	
					preset="slow"
				fi
				
				;;
			*)
				echo "Error: Preset params are not selected."
				log_err "Error: Preset params are not selected. $i"
				exit;
				;;
		esac
	

		if [[ -n $crf_overwrite ]]; then
			crf=$crf_overwrite
		fi
		
		if [[ -n $preset_overwrite ]]; then
			preset=$preset_overwrite
		fi
		
		echo "CRF = $crf"
		echo "params = $params"
		echo "preset = $preset"
		echo "Scale = ${SCALE[@]}"
		
			if [[ "$opus" == "true" ]]; then
				echo "Converting audio to opus"
				echo "Default bitrate ${audio_bitrate}k "
			fi
			
			if [[ "$flac_to_opus" == "true" ]]; then
				echo "flac tracks will be forcibly converted to opus"
			fi
			
			if [[ ! ${#remove_langs[@]} -eq 0 ]]; then
				echo "Tracks (${remove_langs[@]}) will be removed"
			fi 
			
			map_audio=$(GenerateMapAudio "$i" "$opus" "$flac_to_opus")
			
			threads=18
			command="ffmpeg -stats_period 3 -threads \"$(($threads / 2))\" -i \"$i\" ${SCALE[@]} -max_muxing_queue_size 2064 -map 0:v -c:v copy -c:v:0 libx265 -preset \"$preset\" -x265-params \"$params:pools=$threads\" -crf \"$crf\" -pix_fmt yuv420p10le $map_audio \"${i%.*}_k.mkv\""
		#fi
		
		echo "Executing: $command"		
		eval "$command"
		
		# Check the return code
			if [ $? -ne 0 ]; then
				log_err "Conversion error: file \"$i\""
			else
				if [[ $(find "${i%.*}_k.mkv" -size -50M 2>/dev/null) ]]; then
					log_err "Suspiciously small file size: file \"${i%.*}_k.mkv\""
				else 
					fnDelete "$i"
				fi
				echo "Done"
			fi		
		
		date +"%x %X %z"
		
	  fi
  fi
 done