You may need to use converter software to convert your MP3 files to the required codec version (MPEG version 2) and bit rate (48 kbps). One option for this is a command-line tool, FFmpeg. The following command converts the provided
<input-file> to an MP3 file that works with the
ffmpeg -i <input-file> -ac 2 -codec:a libmp3lame -b:a 48k -ar 16000 <output-file.mp3>
Another option is Audacity:
- Open the file to convert.
- Set the Project Rate in the lower-left corner to
- Click File > Export Audio and change the Save as type to
- Click Options, set the Quality to
48 kbpsand the Bit Rate Mode to
This requires the Lame library, which can be found at: http://lame.buanzo.org/#lamewindl.