CLI options that use ffmpeg currently aren't allowed to run for non-mp3 files because of this check. ID3 tags are supported by other file types, so it would be nice to widen that restriction to include a few other common file types found in podcast feeds.
I tested it out locally with a few .m4a files, and writing metadata works fine. I can make the change if you're okay with it.
CLI options that use ffmpeg currently aren't allowed to run for non-mp3 files because of this check. ID3 tags are supported by other file types, so it would be nice to widen that restriction to include a few other common file types found in podcast feeds.
I tested it out locally with a few .m4a files, and writing metadata works fine. I can make the change if you're okay with it.