flac2opus.sh recursively encodes a directory of flac format files to opus, recreating the same directory structure in the output directory. It makes use of all CPU cores (or as many as you would like). The tool does partial updates, so that only new or modified files are (re-)encoded. Encodes are removed if the original no longer exists. Album art is copied to the encoded directory if its name matches {cover,folder}.{jpg,png}.

Usage:
    ./flac2opus.sh [options] <FLAC_DIR> <LOSSY_DIR>

Options:
    -h          Print this help page
    -b <kbit/s> Set which bitrate to encode to
    -f          Rename cover images to folder.{png,jpg} (these are recognized as album art on Android)
    -j <jobs>   Run up to <jobs> encoder processes in parallel.

Flac, opus-tools, bash.