File Juicer
File Juicer for macOS
Overview of Formats

Search & Extract


jpg jpeg 2000 gif png pdf wmf emf tiff eps pict bmp


mov mpeg avi wmv


mp3 wav System 7 au aiff


ascii rtf html


avi cab cache chm dmg doc emlx exe ithmb m4p mht mp3 pdf pps ppt raw swf wps xls zip and other formats

m4v - MPEG4 video

I have not seen mv4 files embedded inside other files, but File Juicer should be able to extract them should it occur. It will be identified as a mp4 extension though.

To convert m4v files to other formats you can use QffmpegX.

iTunes is set as the default application for m4v files, to sync them with the iPod video.