add discordify script

1 files changed, 47 insertions, 0 deletions

diff --git a/discordify.sh b/discordify.sh
new file mode 100755
index 0000000..265e692
--- /dev/null
+++ b/discordify.sh
@@ -0,0 +1,47 @@
+#!/usr/local/bin/fish
+
+if test -z "$argv[1]" -o ! -e "$argv[1]"
+	echo "The input file '$argv[1]' is not present or does not exist"
+	exit
+end
+
+if test -z "$argv[2]"
+	echo "Output file not specified!"
+	exit
+end
+
+set ifile "$argv[1]"
+set ofile "$argv[2]"
+
+# https://stackoverflow.com/q/30977472
+# File length (seconds)
+set length (\
+		ffprobe -i "$ifile" \
+		-show_entries format=duration -v quiet -of csv="p=0"\
+	)
+
+# I think this is supposed to say KB? But the RHS of the division seems to
+# be the filesize in kilobit. It's 7.6 and not 8 (for an 8MB file) because
+# i was getting slightly over 8MB. I think because of file overhead?
+# - 2023-12-09 genny
+#                               v File Size in MB
+set file_bitrate (math "floor((7.6 * 8000) / $length)")
+set audio_bitrate 128
+set video_bitrate (math "$file_bitrate - $audio_bitrate")
+
+echo "Length of '$ifile' is $length and will get a bitrate of "$video_bitrate"kbps"
+echo "Output file will be '$ofile'"
+
+#ffmpeg -i $ifile -vf scale=320:-1 -b:v $bitrate"k" $ofile
+
+# Two pass: http://trac.ffmpeg.org/wiki/Encode/H.264#twopass
+ffmpeg -y -i $ifile \
+	-vf scale=960:-1 \
+	-c:v libx264 -b:v $video_bitrate"k" -pass 1 \
+	-an \
+	-f null /dev/null && \
+ffmpeg -i $ifile \
+	-vf scale=960:-1 \
+	-c:v libx264 -b:v $video_bitrate"k" -pass 2 \
+	-c:a aac -b:a $audio_bitrate"k" \
+	$ofile