Just some stuff about me.
FLAC (Free Lossless Audio Codec) is another free audio codec and container that is known for it’s lossless audio quality. Oddly enough, FLAC is also maintained and developed by the xiph.org foundation. Other than FLACs inconvenience of player support, audiophiles consider FLAC to be one of the best formats for it’s Hi-Res audio.
Although this might be a superior audio quality for some, mp3 is just more convenient and thus converting a FLAC to mp3 is as follows:
$ ffmpeg -i input.flac -ab 320k output.mp3
In this example, the introduction of -ab or bitrate can be noted. The higher the bitrate the higher the quality but larger the file.
Note: this conversion will automatically keep metadata (FFMPEG 3.2 +)