MeGUI is the most comprehensive GUI based ISO MPEG-4 solution. It suports MPEG-4 ASP (XviD & libavcodec MPEG-4) using mencoder, MPEG-4 AVC (x264) using x264.exe or mencoder, (HE)AAC audio using BeSweet & Nero AAC encoder and MP4 muxing using mp4box.

The license of this software is Free, you can free download and free use this audio converter software.