The M4V file format is a video file format developed by Apple and is very close to the MP4 format. The differences are the optional Apple’s DRM copy protection, and the treatment of AC3 (Dolby Digital) audio which is not standardized for the MP4 container.—WikiPedia
How to Convert M4V files to other video formats?
Apple uses the M4V files to encode TV episodes, movies, and music videos in the iTunes Store. The copyright of M4V files may be protected by using Apple’s FairPlay DRM copy protection. To play a protected M4V file, you must choose a reliable third part DRM removal software which can legally remove DRM protections from M4V videos. Here M4V Movie Converter is highly recommend. the DRM removal can help you remove M4V protection and convert the M4V videos to any video like MP4, AVI, MKV, ASF, MOV, WMV, DV etc.
Free download M4V Movie Converter, install and run it.
Simple guide: How to remove DRM from M4V file and Convert M4V to any video formats
Step 1. Import M4V media files
Run the M4V Movie Converter, Click “Add Video” and add your m4v files to the program. it can detect the DRM files automatically.
Step 2. Chooose output format
Select an output format which you preferred for your converted DRM M4V. You can either choose to save the videos to other video formats or get optimized videos for playback on your portable devices or editing on some video editing software. if you like, you can click “Setting” button and select t the video parameters (resolution, frame rate, encoder, and bit rate) or audio parameters (such as sample rate, channel, encoder and bit rate).
Step 3. Start the M4V to any video format Conversion
After a short setup, click the “Convert” button to begin the conversion process, After a successful conversion, click “Find Target” to locate the converted DRM-free video files and then transfer them to your tablets or Phones.