It should be enough if you just rename MP4 to M4V, as both are same format.
Convert MPEG-4 video file format to MPEG-4 video file format.
We have found 16 software records in our database eligible for .mp4 to .m4v file format conversion.
Microsoft Windows software - convert mp4 to m4v on Windows
A timeline-based video editing software from Adobe
Convert from mp4 file format
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned mp4 to m4v. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
A DRM remover and media converter
One of the most popular and succesfful free video conversion sofrware
A multimedia converter for formats suitable for iPad tablets
A Software for MP4/3GP file conversions
A fully-featured video conversion program
Universal All Purpose Free Media, Audio & Video Converter Player Recorder
A software video converter for Apple TV
Apple macOS / Mac OS X software - convert mp4 to m4v on OS X
A video converting tool for OS X
A multimedia converter software
A fully-featured video converter for Mac
Universal video converting software for Mac
Mac version of Adobe's prime video editing software
A multimedia importer for iTunes
Multiplatform software - convert mp4 to m4v on any platform
Program for multimedia streaming and conversion