new: files for re-encoding audio (removing covers, optimising for streaming (AAC))

change: made script less error-prone

scripts/reencode_m4a.sh

@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+for file in ./*.m4a; do
+   map='';
+   if [[ $# > 0 && $1 == 'map' ]]; then
+      map='-map 0:0';
+   fi
+   echo "ffmpeg -i '$file' -c:a copy $map -movflags +faststart '../reencode/$file'";
+   ffmpeg -i "$file" -c:a copy $map -movflags +faststart "../reencode/$file";
+done