How to convert DRM protected iTunes 1080p/720p HD M4V Movies to MP4?

The M4V is actually a kind of MP4 file that adopts the H.264/AVC codec, has a high compression rate. All commercial movies/videos and television shows in the iTunes store are actually available in the M4V format, not only this Apple add DRM protection to the iTunes’ M4V files to prevent customers from re-distributing them onto Non-Apple media player