We recommend! The Mobile Media Converter is a free video and audio converter that uses ffmpeg to convert between popular desktop formats like MP3, Windows Media Audio (wma), Ogg Vorbis Audio (ogg), Wave Audio (wav), MPEG video, AVI, Windows Media Video (wmv), Flash Video (flv) and commonly used mobile phones formats like AMR audio (amr, awb) and 3GP video. Also, iPod/iPhone compatible MP4 video is also supported.
See Also: Backup & Restore your Mobile Phone with Mobical
Mobile Media Converter has a very easy-to-use and simple GUI (Graphical User Interface) that helps even the most amateur user. Most of the times, the only data that you must enter is the input file(s) or just drag and drop the input file! The 3GP and AMR formats are used by mobile phones for MMS, for video and sound recordings, etc.
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very good