Encode FLAC audio to MP3

Low quality encoding:
128Kbps CBR + 2 channels + 44100Hz sampling frequency.
It should be good enough for listening on your car, on the bus with your smartphone and headphones, etc. avconv -i input.flac -ab 128k -ac 2 -ar 44100 output.mp3

High quality encoding:
 avconv -i input.flac -ab 196k -ac 2 -ar 48000 output.mp3