2025-06-17 12:53:01 -07:00
2 changed files with 186 additions and 54 deletions
--- a/README.md
+++ b/README.md
@ -0,0 +1,42 @@
+# burnSubs
+You found my burnSubs tool. The goal for this tool is to ease the
+conversion of arbitrary video files with soft-subtitles in the SSA/ASS
+Substation Alpha format into simple stereo hard-subtitled video files.
+
+## Features
+* softsub to hardsub conversion
+* embedded font files
+* selecting specific audio streams
+* selecting specific video streams
+* automatic selection of language preferences
+* default surround sound to stereo down-mixing
+  * opt out CLI flag available
+* anti-clobbering default behavior
+* auto-cleanup on error
+
+## Prerequisite Tools
+Firstly, the tool will yell at you if the tools it needs don't exist.
+Feel free to just run the tool, and it will let you know what you're
+missing.
+
+* [`ffmpeg`](https://ffmpeg.org/) - the one and only
+  * `ffprobe` - usually comes with ffmpeg
+* [`jq`](https://stedolan.github.io/jq/) - file/pipe based JSON processor
+
+
+## How does it work?
+`burnSubs` takes an input video file and tries to figure out what
+audio streams and subtitle streams exist within the file. It stores
+metadata in `/tmp` while it runs. When running it will pull the
+streams within the input file, and try to select Japanese language
+audio streams, and a non-signs subtitle stream (i.e. a full language
+subtitle stream) to add to the output video.
+
+Before transcoding it will then extract the subtitle file to pass into
+`ffmpeg`'s subtitle burn in filter, and will try to down-mix any
+surround sound input streams to stereo. Downmixing, track selection,
+clobbering behavior, and verbosity can all be controlled to a limited
+extent by CLI flags.
+
+## Can you make it do *XYZ*.
+Give me an enhancement request in github and I'll take a look.
--- a/162
+++ b/162
@ -5,18 +5,18 @@ set -o errexit

 ################################################################################
 # burnSubs
-# version 0.11.0
-#################3
+# version 0.13.3
+#################
 # Wishlist:
 #   queue encodes
 #   finish TODOs
 #	finish help flag
 #	audio recode flag
 #
-# Changes
-#   automatically select JPN audio if more than one audio channel found.
 ################################################################################

+DEFAULTS_OPTS_CRF=18
+
 function machineSetup() {
 	# Default setup
 	export FF_ENC="libx264"
@ -24,7 +24,7 @@ function machineSetup() {
 	export FILT_PFX=""
 	export FILT_SFX=""
 	
-	CRF=${OPTS_CRF:-23}
+	CRF=${OPTS_CRF:-$DEFAULTS_OPTS_CRF}
 	export FF_STD="-preset myTranscoderPreset -crf $CRF -tune animation \
 		-preset medium -movflags +faststart"
 	export FF_EXT="-profile:v high -level 4.0"
@ -55,7 +55,7 @@ function machineSetup() {
 			#export FFMPEG="/opt/ffmpeg-nvenc/bin/ffmpeg"
 			export LD_LIBRARY_PATH="/opt/ffmpeg-nvenc/lib"
 			export FF_EXT="${FF_EXT} -pix_fmt yuv420p"
-		elif [[ "$(hostname)" == "grad-heo-lappy" ]]; then
+		elif [[ "$(hostname)" == "random-vaapi-intel-laptop" ]]; then
 			echo "   > Hostname: $(hostname)"
 			export OPTS_ENC="vaapi"
 		else
@ -65,20 +65,6 @@ function machineSetup() {
 		fi
 	fi

-	# Configure audio filtergraph if needed.
-	if [[ "${OPTS_TRANS_AUDIO}" == true ]]; then
-		FILT_AUDIO="-c:a aac"
-		if [[ "${OPTS_LPF_AUDIO}" == true ]]; then
-			FILT_AUDIO="-filter:a highpass=f=7 ${FILT_AUDIO}"
-		fi
-
-		if [[ "$(hostname)" == "Ram-the-Red" ]]; then
-			FILT_AUDIO="${FILT_AUDIO} -strict -2"
-		fi
-	else
-		FILT_AUDIO="-c:a copy"
-	fi
-
 	# Configure the encoder based upon the specific encoder chain required
 	## NVIDIA GPU Encode/Decode
 	if [[ "$OPTS_ENC" == "nvidia" ]]; then
@ -151,9 +137,9 @@ function setupBins() {
 	setAndValidateBin "ffmpeg" "FFMPEG"
 	setAndValidateBin "ffprobe" "FFPROBE"
 	setAndValidateBin "jq" "JQ"
-	setAndValidateBin "python3" "PYTHON3"
-	setAndValidateBin "awk" "AWK"
-	setAndValidateBin "date" "DATE"
+	#setAndValidateBin "python3" "PYTHON3"
+	#setAndValidateBin "awk" "AWK"
+	#setAndValidateBin "date" "DATE"
 }

 # Used by the above function to evaluate overrides if they are set, and
@ -187,6 +173,7 @@ function doCleanup() {
 		echo "=> Cleaning up."
 		rm -r "$TMP"
 	else
+		set +x
 		echo "tmp dir: $TMP"
 	fi
 	
@ -291,13 +278,48 @@ function parseStreams() {
 	# Extract subtitles
 	#$item.codec_type == "subtitle" \&\& 
 	# shellcheck disable=SC2016
-	"$JQ" 'reduce .streams[] as $item ([]; if ($item.codec_name == "ass") then [.[],$item] else . end) | reduce .[] as $item ([]; [.[],{t:($item.tags.title),i:($item.index),lang:$item.tags.language, disposition:$item.disposition}]) | reduce .[] as $item ([]; [.[],{t:($item.t // ($item.lang + "-" + ($item.i | tostring))),i:$item.i,lang:$item.lang,disposition:$item.disposition}])' "${STREAMS_ALL}" > "${STREAMS_SUB}"
+	"$JQ" 'reduce .streams[] as $item ([]; if ($item.codec_name == "ass" or $item.codec_name == "dvd_subtitle") then [.[],$item] else . end) | reduce .[] as $item ([]; [.[],{t:($item.tags.title),i:($item.index),lang:$item.tags.language, disposition:$item.disposition, codec:($item.codec_name)}]) | reduce .[] as $item ([]; [.[],{t:($item.t // ($item.lang + "-" + ($item.i | tostring))),i:$item.i,lang:$item.lang,disposition:$item.disposition,codec:$item.codec}])' "${STREAMS_ALL}" > "${STREAMS_SUB}"
 	export SUB_COUNT=$("$JQ" 'length' "${STREAMS_SUB}")
 	# shellcheck disable=SC2016
-	"$JQ" 'reduce .streams[] as $item ([]; if ($item.codec_type == "audio") then [.[],$item] else . end) | reduce .[] as $item ([]; [.[],{t:($item.tags.title),i:($item.index),lang:$item.tags.language, disposition:$item.disposition}]) | reduce .[] as $item ([]; [.[],{t:($item.t // ($item.lang + "-" + ($item.i | tostring))),i:$item.i,lang:$item.lang,disposition:$item.disposition}])' "${STREAMS_ALL}" > "${STREAMS_AUDIO}"
+	"$JQ" 'reduce .streams[] as $item ([]; if ($item.codec_type == "audio") then [.[],$item] else . end) | reduce .[] as $item ([]; [.[],{t:($item.tags.title),i:($item.index),lang:$item.tags.language, disposition:$item.disposition, chan:{channels:$item.channels, channel_layout:$item.channel_layout}}]) | reduce .[] as $item ([]; [.[],{t:($item.t // ($item.lang + "-" + ($item.i | tostring))),i:$item.i,lang:$item.lang,disposition:$item.disposition, chan:$item.chan}])' "${STREAMS_ALL}" > "${STREAMS_AUDIO}"
 	export AUDIO_COUNT=$("$JQ" 'length' "${STREAMS_AUDIO}")
 	
 	
+}
+
+function setupAudioTranscode() {
+	if [[ $AUDIO_COUNT -ne 1 ]]; then
+		CHANNEL_COUNT=$($JQ '.[] | select(.i == '$AUDIO_INDEX') | .chan.channels' "$STREAMS_AUDIO")
+		CHANNEL_LAYOUT=$($JQ '.[] | select(.i == '$AUDIO_INDEX') | .chan.channel_layout' "$STREAMS_AUDIO")
+	else
+		CHANNEL_COUNT=$($JQ '.[] | .chan.channels' "$STREAMS_AUDIO")
+		CHANNEL_LAYOUT=$($JQ '.[] | .chan.channel_layout' "$STREAMS_AUDIO")
+	fi
+
+	if [[ "${CHANNEL_COUNT}" == "6" && "${CHANNEL_LAYOUT}" == '"5.1"' ]]; then
+		# check if we're 5.1 and if so flag transcode.
+		export OPTS_TRANS_AUDIO=true
+	elif [[ "${CHANNEL_COUNT}" != "2" && "${CHANNEL_LAYOUT}" != '"5.1"' ]]; then
+		echo "ERROR: Trying to enocde non 5.1 and non-stereo audio stream."
+		exit 1
+	fi
+	
+	# Configure audio filtergraph if needed.
+	if [[ "${OPTS_TRANS_AUDIO}" == true ]]; then
+		FILT_AUDIO="-c:a aac"
+		if [[ "${OPTS_LPF_AUDIO}" == true ]]; then
+			FILT_AUDIO="-filter:a highpass=f=7 ${FILT_AUDIO}"
+		fi
+		if [[ "${OPTS_SURROUND_PRESERVE}" == false ]]; then
+			# From https://superuser.com/questions/852400/properly-downmix-5-1-to-stereo-using-ffmpeg
+			# Nightmode Formula
+			FILT_AUDIO="-filter:a pan=stereo|FL=FC+0.30*FL+0.30*BL|FR=FC+0.30*FR+0.30*BR ${FILT_AUDIO}"
+		fi
+	else
+		FILT_AUDIO="-c:a copy"
+	fi
+
+
 }

 function listSubtitles() {
@ -310,7 +332,11 @@ function listSubtitles() {
 		X_TITLE=$($JQ '.['$iSUB'].t' $STREAMS_SUB | tr -d '"')
 		X_INDEX=$($JQ '.['$iSUB'].i' $STREAMS_SUB | tr -d '"')
 		X_LANG=$($JQ '.['$iSUB'].lang' $STREAMS_SUB)
+		X_CODEC=$($JQ '.['$iSUB'].codec' $STREAMS_SUB)
 		printf " %2d: %4s %s\n" $X_INDEX $X_LANG "$X_TITLE" 
+		if [[ "$X_CODEC" != "ass" ]]; then
+			printf "      format: %s\n" $X_CODEC
+		fi
 	done
 	echo ""
 	return
@ -342,18 +368,29 @@ function selectSubs() {
 		export SUBTITLE_INDEX=-1
 	else
 		if [[ $OPTS_SELSUB -lt 0 && $SUB_COUNT -gt 1 ]]; then
-			OPTS_SELSUB_LANG="${OPTS_SELSUB_LANG:-eng}"
-			LANG_TEST=$($JQ '[.[].lang] | index("'${OPTS_SELSUB_LANG}'")' "$STREAMS_SUB")
 			echo "   > WARNING: Multiple subtitles!"
 			printf "       Using default selection rules... "
-			if [[ "$LANG_TEST" == "null" ]]; then
+			OPTS_SELSUB_LANG="${OPTS_SELSUB_LANG:-eng}"
+			LANG_TEST=$($JQ '[.[].lang | match("'${OPTS_SELSUB_LANG}'")] | length' "$STREAMS_SUB")
+			if [[ "$LANG_TEST" == "0" ]]; then
 				echo "English not found!"
 				echo "    ==> Reverting to first subtitle file."
 				export SUBTITLE_INDEX=$($JQ '.[0].i' "$STREAMS_SUB")
-			else
+			elif [[ "$LANG_TEST" == "1" ]]; then
+				LANG_SINGLE_SELECT=$($JQ '[.[].lang] | index("'${OPTS_SELSUB_LANG}'")' "$STREAMS_SUB")
 				# we found english
 				echo "English found"
-				export SUBTITLE_INDEX=$($JQ '.['$LANG_TEST'].i' "$STREAMS_SUB")
+				export SUBTITLE_INDEX=$($JQ '.['$LANG_SINGLE_SELECT'].i' "$STREAMS_SUB")
+			else
+				# try to avoid a signs and lyrics track
+				LANG_SINGLE_SELECT=$($JQ '[.[].lang] | index("'${OPTS_SELSUB_LANG}'")' "$STREAMS_SUB")
+				echo "Multiple english tracks found."
+				export SUBTITLE_INDEX=$($JQ 'reduce .[] as $trk ([]; if ($trk.lang == "'${OPTS_SELSUB_LANG}'" and (( ($trk.t | test("lyrics";"i")) or ($trk.t | test("signs";"i")) or ($trk.t | test("dub";"i")) )|not) ) then [.[],{t:$trk.t,i:$trk.i}] else . end) | .[].i' "$STREAMS_SUB")
+				# And display rejected subtitles too.
+				SUBTITLE_REJECT_LIST=($($JQ 'reduce .[] as $trk ([]; if ($trk.lang == "'${OPTS_SELSUB_LANG}'" and (( ($trk.t | test("lyrics";"i")) or ($trk.t | test("signs";"i")) or ($trk.t | test("dub";"i")) )) ) then [.[],{t:$trk.t,i:$trk.i}] else . end) | .[].t' "$STREAMS_SUB"))
+				for REJECT_SUB in ${SUBTITLE_REJECT_LIST[@]}; do
+					echo "       > rejecting ${REJECT_SUB}"
+				done
 			fi
 		else
 			if [[ $SUB_COUNT -eq 1 ]]; then
@ -375,12 +412,14 @@ function selectSubs() {
 			printf "       Using default selection rules... "
 			if [[ "$LANG_TEST" == "null" ]]; then
 				echo "Japanese audio not found!"
-				echo "    ==> Reverting to first subtitle file."
+				echo "    ==> Reverting to first audio stream."
 				export AUDIO_INDEX=$($JQ '.[0].i' "$STREAMS_AUDIO")
 			else
 				# we found english
 				echo "Japanese audio found"
 				export AUDIO_INDEX=$($JQ '.['$LANG_TEST'].i' "$STREAMS_AUDIO")
+				AUDIO_STREAM_TITLE=$($JQ '.['$LANG_TEST'].t' "$STREAMS_AUDIO")
+				echo "    ==> stream has title ${AUDIO_STREAM_TITLE}"
 			fi
 		else
 			AUDIO_INDEX=$OPTS_SELAUDIO
@ -409,17 +448,21 @@ function extractSubs() {
 function doTranscode() {
 	echo "=> Starting transcode:"
 	# shellcheck disable=SC2086
-	echo "$FFMPEG" ${FF_HW} -i "${INPUT_VIDEO}" -sn ${LIM_TIME} \
+	echo "$FFMPEG" ${FF_VERBOSITY} ${FF_HW} -i "${INPUT_VIDEO}" \
+		-sn ${LIM_TIME} \
 		-filter:v "${FILT_PFX}ass=${SUBTITLE_FILE}${FILT_SFX}" \
-		${FILT_AUDIO} -c:v "${FF_ENC}" ${FF_STD} ${FF_EXT} ${FF_AUDIO}	\
+			${FILT_AUDIO} \
+		-c:v "${FF_ENC}" ${FF_STD} ${FF_EXT} ${FF_AUDIO}	\
 		"${OUTPUT_VIDEO}"
 	if [[ "$OPTS_DRYRUN" == true ]]; then
 		return
 	fi
 	# shellcheck disable=SC2086
-	"$FFMPEG" ${FF_HW} -i "${INPUT_VIDEO}" -sn ${LIM_TIME} \
+	"$FFMPEG" ${FF_VERBOSITY} ${FF_HW} -i "${INPUT_VIDEO}" \
+		-sn ${LIM_TIME} \
 		-filter:v "${FILT_PFX}ass=${SUBTITLE_FILE}${FILT_SFX}" \
-		${FILT_AUDIO} -c:v "${FF_ENC}" ${FF_STD} ${FF_EXT} ${FF_AUDIO}	\
+			${FILT_AUDIO} \
+		-c:v "${FF_ENC}" ${FF_STD} ${FF_EXT} ${FF_AUDIO}	\
 		"${OUTPUT_VIDEO}"
 	export FINAL_STATUS=$?
 }
@ -477,6 +520,8 @@ OPTS_DEBUG=false
 OPTS_LPF_AUDIO=false
 OPTS_TRANS_AUDIO=false
 OPTS_derived_NO_OUTPUT=false
+OPTS_VERBOSITY=1
+OPTS_SURROUND_PRESERVE=false
 unset OPT_CRF
 # this is the --icon flag passed to notify-send at the end of the transcode
 NOTIFY_ICON="face-tired"
@ -496,7 +541,8 @@ FINAL_STATUS=1

 ######
 # Reformat and organize the input strings
-OPT_STRING=$(getopt -o 'hkls:dt:' --long 'help,psoft,soft,dry,crf:,audio,audiofix,alocale:,slocale:' -- "$@")
+OPT_STRING=$(getopt -o 'hkls:a:dt:vq' \
+	--long 'help,psoft,soft,dry,crf:,audio,audiofix,alocale:,slocale:,verbose,quiet,keep-surround' -- "$@")
 # reassign them as positional arguments
 eval set -- "$OPT_STRING"

@ -572,6 +618,13 @@ while true; do
 			shift
 			continue
 		;;
+		"--keep-surround")
+			OPTS_SURROUND_PRESERVE=true
+			OPTS_TRANS_AUDIO=true
+			echo ">> !! preserving 5.1/7.1 surround sound if available."
+			shift
+			continue
+		;;
 		"--soft")
 			OPTS_FORCESOFT=true
 			echo ">> !! forcing software decoding/encoding."
@ -597,6 +650,22 @@ while true; do
 			shift
 			continue
 		;;
+		"--verbose"|"-v")
+			if [[ ${OPTS_VERBOSITY} -ne 0 ]]; then
+				OPTS_VERBOSITY=2
+				echo ">> !! print ffmpeg header."
+			else
+				echo ">> !! Ignoring verbosity flag. Quiet takes precidence."
+			fi
+			shift
+			continue
+		;;
+		"--quiet"|"-q")
+			OPTS_VERBOSITY=0
+			echo ">> !! print ffmpeg header."
+			shift
+			continue
+		;;
 		"--")
 			shift # all arguments parsed
 			break
@ -612,9 +681,11 @@ while true; do

    -t <t>          ffmpeg encoding time limit
    --crf <#>       override CRF setting
+                        default: $DEFAULTS_OPTS_CRF
    --soft          force software decode and encode
    --psoft         use software encoding (allow hardware decode when available)
    --audiofix      transcode audio
+	--keep-surround	try to preserve surround sound rather than downmixing to stereo.
    --lpf           transcode audio, and low-pass filter as well

    -l              list subtitles and audio tracks (no encoding)
@ -629,6 +700,8 @@ while true; do

    -d              debug (no cleanup)
    --dry           dry run (no encoding)
+    -q, --quiet     make ffmpeg shutup
+    -v, --verbose   show all FFMPEG details (except that ruddy header)
 _EOT
 			exit
 		;;
@ -654,6 +727,19 @@ else
 	exit
 fi

+# Actual verbosity parsing
+if [[ ${OPTS_VERBOSITY} -le 0 ]]; then
+	FF_VERBOSITY="-hide_banner -loglevel error"
+elif [[ ${OPTS_VERBOSITY} -eq 1 ]]; then
+	FF_VERBOSITY="-hide_banner -loglevel error -stats"
+else # ie [[ ${OPTS_VERBOSITY} -ge 2 ]]; then
+	FF_VERBOSITY="-hide_banner"
+fi
+
+if [[ "$OPTS_DEBUG" == "true" ]]; then
+	set -x
+fi
+
 ###############
 # Configure the encoder based upon the hostname
 machineSetup
@ -682,6 +768,10 @@ fi
 selectSubs
 # extract the selected subtitle file
 extractSubs $SUBTITLE_INDEX
+
+# Configure the audio straem
+setupAudioTranscode
+
 # Set the bitrate if that function wasn't disabled
 runExtraProc "h264_vaapi"