The Windows Media Video codec (.WMV) is a subset of Microsoft's Advanced Systems Format (ASF) container format. WMV files can be played by players such as MPlayer or Windows Media Player. Mp4, short for MPEG-4 Part 14, is a multimedia container format standard specified as a part of MPEG-4. It is most commonly used to store digital audio and digital video streams, especially those defined by MPEG

Convertion

Of course we can convert wmv to mp4, we have the wmv to mp4 video converter for mac/ win.