MP3
        An older-generation MPEG1 audio codec, now the most popular audio codec in the world. AAC and Vorbis are better quality, but nearly every device in existence supports MP3.
        
            Options
            
                - 
                    VBR Quality (0 - 9)
 Set a specific audio quality (recommended). Default is 4. Lower numbers are higher quality.
 vbr-quality=2
 
- 
                    Bitrate (number)
 Set a specific bitrate in kbps to control file size. Default is 128.
 bitrate=196
 
- 
                   Variable Bitrate (number)
 Set bitrate mode.
 
                       - none: constant bitrate (default)
- old: old VBR algorithm
- abr: VBR average bitrate
- new: Lame's new VBR algorithm (recommended)
 vbr=new