Rescuing ringtones from the 2000s
Old memory cards and phone backups are full of .mmf files: the ringtone you had for years, a voice tone recorded by a friend, the alarm that woke you up at school. Modern phones and computers cannot play them. To convert MMF to MP3, the converter reads the audio stored in the SMAF file and encodes it as MP3, which plays everywhere.
Which files work
SMAF files store either recorded audio or synthesizer notes, and sometimes both. The converter handles the recorded audio (Yamaha ADPCM or PCM). Typical examples are voice ringtones, sound effects and "true tone" music clips.
Classic polyphonic melody ringtones, however, were often pure note data played by the phone's synthesizer chip. Such files have no recording inside, and this converter cannot render them; they will fail to open or produce silence. If you still have a phone that plays them, the practical way to keep them is to record the phone's speaker with the Audio Recorder in a quiet room.
Settings
The audio in MMF files is modest: usually mono, 8–16 kHz, 4 bits per sample. A good MP3 for it is small:
- 64 kbps mono covers 8 kHz tones fully, at about 0.5 MB per minute.
- 96 kbps mono for 16–22 kHz tones with music.
- Stereo or 320 kbps adds size without adding sound.
The MP3 can be written at 44.1 kHz for compatibility, or kept near the original rate. Either way, the converter cannot recreate high frequencies that the phone format never stored, so the tone will still sound like a phone from that era.
Making them sound better
Old tones are often quiet or noisy. Normalize brings them to a consistent level, and gentle Noise Reduction can soften the hiss typical of 4-bit audio. A little EQ in the middle frequencies can make a voice tone clearer. Add your whole ringtone folder at once to convert it in one batch, and give the files clear names, because MMF files rarely contain titles.