Upload M4R file from your device memory or cloud or via URL
Once uploading is complete, press the convert button
Wait until the end of the conversion and download new MMF fileL
M4A is an audio file compressed using MPEG-4 technology, which has a lossy compression algorithm. The M4R file contains the ringtone in the M4A MPEG-4 file format, which uses the default audio format to store the song in the iPhone. The M4R format, like M4A, is designed to download audio to Apple devices through iTunes. Such a file can be created by converting other formats or uploading it from the official iTunes store. You don't have to look for converters or special programs, you can make m4r from m4a using standard tools of any operating system by changing the last letter of the extension manually. But for this to work like an iPhone ringtone, remember that it can only be created from songs purchased from the iTunes music store.
The MMF format was created for mobile devices. These files most often store cell phone ringtones, although sometimes other objects such as graphics and text, as well as audio data can be found in them. Can be created from .WAV or .MID files using Yamaha SMAF Tools. There is no program to convert MP3 directly to MMF yet, so the MP3 file must first be converted to WAVE format (file with the .wav extension).