Your best bet to convert M4V videoes to 264 format is to use Freemake Video Converter. It might also be possible using Adobe Premiere Pro or similar programs.
Convert MPEG-4 video file format to H.264/MPEG-4 AVC video data.
We found 4 software records in the database related to .m4v to .264 file format conversion.
Microsoft Windows software - convert m4v to 264 on Windows
One of the most popular and succesfful free video conversion sofrware
Convert from m4v file format
|Yes, Freemake Video Converter supports m4v file conversion as a source file type.||No||No||No||No||No||No||No|
|Yes, Freemake Video Converter supports 264 file conversion as a target file type.||No||No||No||No||No||No||No|
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 m4v to 264. 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 timeline-based video editing software from Adobe
Apple macOS / Mac OS X software - convert m4v to 264 on OS X
A video converting tool for OS X
Mac version of Adobe's prime video editing software