How to use ffmpeg to convert a flac file to alac and preserving all metadatas?

Question

I use this loop to convert flac to alac :

for i in *.flac; do ffmpeg -i "$i" -y -vn -c:a alac "${i%.flac}".m4a; done

But some tags are not exported. I tried to use the -map_metadata 0 -id3v2_version 2 flag but it does not change anything.

Here you can find the tags that are copied (with or without the -map_metadata) :

• original tags
• tags copied

When I use XLD Mac software it works perfectly but for some reasons I'd like to use CLI to convert flac files.

Answer 1

Something you can do, to help ensure proper tagging, is the conversion separate from the tagging.

#!/bin/bash

for i in *.flac; do
    filename="${i%.*}"
    ffmpeg -i "$i" -an -f ffmetadata "$filename".id3
    ffmpeg -i "$i" -y -c:a alac -map_metadata -1 no_tag_"$filename".m4a
    ffmpeg -i no_tag_"$filename".m4a -c:a copy -i "$filename".id3 -map_metadata 1 -id3v2_version 3 "$filename".m4a
done

rm *.id3 no_tag_*

exit 0

Save: manual_tags.sh
Make executable: chmod +x manual_tags.sh
Usage: ./manual_tags.sh