sync/scripts/transcode_m4a.sh

#!/usr/bin/env bash
set -euo pipefail

for file in ./*.$1; do
   map='';
   if [[ $# > 1 && $2 == 'map' ]]; then
   	  map='-map 0:0';
   fi
   dest=../transcode_m4a
   if [[ !(-d $dest) ]]; then
      mkdir $dest
   fi
   echo "ffmpeg -i '$file' -c:a libfdk_aac -profile:a aac_he -b:a 64k -movflags +faststart $map '$dest/${file%$1}m4a'";
   ffmpeg -i "$file" -c:a libfdk_aac -profile:a aac_he -b:a 64k -movflags +faststart $map "$dest/${file%$1}m4a";
done