LAME (recursive acronym Lame ain't an MP3 encoder) has been an exceptional application for creating MP3 audio files from other formats (e.g., WAV, FLAC, MPEG-1, MPEG-2) or even for re-encoding existing MP3 files. Creating MP3 files is popular due to their extensive use in portable media players, as they combine an impressive reduction in file size with minimal loss from uncompressed audio. LAME was first released 27 years ago, has been in regular development since, and is now bundled with the very popular audio editor, Audacity, and other excellent audio conversion applications like FFmpeg. The following are several examples of how to use LAME on the command line, convert files, and automate this process, along with the use of cdparanoia and ffmpeg. This might be handy if you want to (for example) back up a collection of CDs.

To extract files from existing media, use cdparanoia, a delightfully old and stable tool where the last release was September 2008 and the front-end for libparanoia, which is also used in the cdrtools suite, which can be used for the creation of audio and data CDs. To use cdparanoia to extract files from disk, first use the command to get the information about what drives you have, i.e., $ cdparanoia -vsQ, a verbose search and query. Then, to extract the files, simply use $ cdparanoia -B, batch mode, saving each track to a separate file. The default format is WAV; if one wants RAW, use $ cdparanoia -rB.

Using LAME to convert files, the simplest action is to convert a file with no options. e.g., $ lame input.wav output.mp3. This can be extended with the numerous options offered by LAME. Perhaps the most common is the -V% (variable bit rate) (e.g., $ lame -V0 input.wav output.mp3. Values are from 0 to 9, where 0 is the highest quality (but largest file size), which is good for very high-fidelity recording, whilst 9.999 is the lowest one, which is fine for low fidelity needs (e.g., a monophonic voice recording); the default is 4. Run a test on a WAV file to see if you can detect the difference in audio quality and check the file size differences. Note that despite being a good encoder, LAME is not recommended for archives; use a lossless audio codec (e.g., FLAC).

If one has multiple files to convert, a short loop is an effective strategy (e.g., $ for item in *.wav; do lame "$item" "${item%.wav}.mp3"; done). This is certainly preferable to opening files with a GUI application and running the conversion one file at a time. If one has a number of large files, then use of GNU Parallel is an excellent choice (e.g., $ parallel lame -V0 {} {.}.mp3 ::: *.wav). On a sample CD, the loop conversion took 57.201 seconds; with parallel, 13.264 seconds; it is fairly clear how this makes a difference if you have a large number of CDs. Note that with a smaller number and size of files, the use of GNU Parallel will actually take a longer time than a loop due to the overhead of splitting up the tasks. Certainly, if you are converting the WAV files from a CD, use GNU Parallel. Note that GNU Parallel will use all the cores available on a system; the number of concurrent jobs can be limited with the -j option (e.g., parallel -j2 lame -V0 {} {.}.mp3 ::: *.wav).

Finally, there is a great little tool called mp3wrap, which can wrap multiple MP3 files into a single MP3, but keeps filenames and metadata information, which can be later split back to original files (using the mp3splt command). The output file will be named OUTPUTFILE_MP3WRAP.mp3; keep the MP3WRAP string so that the split program detects that the file is wrapped with this utility. To create a single file, simply use $mp3wrap album.mp3 track*.mp3.