convaudi is a handy tool to massively convert audio files of various formats into other formats. It is built on (and supports all formats supported by) FFmpeg.
FFmpeg has to exist in your PATH. Also, the following gems have to be installed: popen4, thread_storm, progressbar.
$ ruby convaudi.rb [options] Available options: -c, --concurrency [NUM_OF_CPUS] The number of threads executing conversion at any given point. Default: 2 -q, --quality [QUALITY] The quality in which to transform the converted files. Default: 320k -p, --pretend Show only what the script is going to do: do not really convert or touch any file. Default: false -d, --delete Whether to delete the original file upon successful (only) converion. Default: false -i, --input [EXTENSIONS] The filetypes that will be converted. Default: .mpc,.flac,.wma -o, --output-format [EXTENSION] The output filetype. Default: .m4a --help Show this help message