flacsync makes it easy to keep up-to-date copies of MP3 files in music
directories containing flacs.
See flacsync.py -h for usage information (you can change the directory to parse
with -d and the number of worker threads with -n).
It tries to copy as many FLAC tags to MP3 tags as possible. If there are
photos in the same folder, it will try to embed them into the MP3 based on
the filename (e.g. images containing the word "front" are embedded and given
the "Front Cover" tag.
A tool for automatically creating (and keeping up-to-date) MP3s from FLACs