Thread: Three main types of bitrate

The three main types of bitrate are constant (CBR), variable (VBR) and average (ABR). CBR maintains a constant sound quality, and is not as optimal as VBR, which adjusts the bitrate according to the requirements of each part of a track. ABR restricts the size of the output file, so the bitrate is calculated to that target. LAME, however offers only the former two options. Ripping is permanent, so to increase the quality or decrease the file size, you'll need the original CD. Re-encoding an existing MP3 file to a different bitrate will result in lower quality.