add script to transcode old files to m4a

Author: WMFO Administrator

scripts/batch-transcode.sh

@@ -0,0 +1,34 @@
+#!/bin/bash
+
+INPUT_DIR=/var/www/archive.wmfo.org/archives
+
+MAX_AGE=` echo "$((365*24*3600))"`
+CONVERTED_EXTENSION=m4a
+
+for full_filename in $INPUT_DIR/2018-03*.s16 ; do
+	filename=$(basename $full_filename)
+        extension=${filename##*.}
+        basefilename=${filename%.*}
+        directory=$(dirname $full_filename)
+        input_date=`echo "$basefilename:00:00" | sed 's/_/ /g' | sed 's/U//g'`
+	utc_file_seconds=`date -u -d "$input_date" +%s`
+	utc_current_seconds=`date -u +%s`
+	seconds_age=`echo "$(($utc_current_seconds - $utc_file_seconds))"`
+	output_filename="${full_filename%.s16}.m4a"
+	if [ -f $output_filename ] ; then
+		converted_filesize=`du -k "$output_filename" | cut -f1`
+		original_filesize=`du -k "$full_filename" | cut -f1`
+		ratio=`echo "$(($original_filesize / $converted_filesize))"`
+		if [ $ratio -lt 13 ] ; then
+			echo "File: $full_filename has $CONVERTED_EXTENSION file of sufficient size. Removing."
+			mv -n $full_filename ${full_filename}.to-delete
+		else
+			echo "File: $full_filename has $CONVERTED_EXTENSION TOO SMALL. Removing."
+			mv -n $output_filename ${output_filename}.to-delete
+		fi	
+	fi
+	if ! [ -f $output_filename ] && [ $seconds_age -gt $MAX_AGE ] ; then
+		echo "Age $seconds_age is greater than MAX_AGE, must convert: $full_filename"
+        	/usr/local/bin/ffmpeg -f s16le -ar 48000 -ac 2 -i $full_filename -c:a libfdk_aac -b:a 128k $output_filename < /dev/null
+	fi
+done