無料オンラインMP4からWMAへのコンバーター

MP4 is an extension defined by MPEG-4 video standard and AAC audio standard. It is a container that supports all kinds of media such as video, audio, subtitles, 2D and 3D graphics. It is possible to open MP4 file with almost any player on Windows but on Mac you should use a plug-in or just convert the file to another format.

This is a proprietary format developed by Microsoft. Users have noticed low error resilience: sometimes insignificant damage to the file can cause the file not to play. Besides this, the closed format hampers its proliferation outside of Windows platforms.