M4V

The M4V file format is a video container format developed by Apple and is very similar to the MP4 format. The primary difference is that M4V files may optionally be protected by DRM copy protection. Apple uses M4V to encode video files in its iTunes Store. Unauthorized reproduction of M4V files may be prevented using Apple's FairPlay copy protection. A FairPlay-protected M4V file can only be played on a computer authorized (using iTunes) with the account that was used to purchase the video.

- - Wikimedia

MP4

MPEG-4 Part 14 or MP4 is a digital multimedia container format most commonly used to store video and audio, but it can also be used to store other data such as subtitles and still images. Like most modern container formats, it allows streaming over the Internet. The only official filename extension for MPEG-4 Part 14 files is .mp4. MPEG-4 Part 14 (formally ISO/IEC 14496-14:2003) is a standard specified as a part of MPEG-4.

- - Wikimedia

Step-By-Step to Convert M4V to MP4

Interface

Step 1. Download and install the program, then double click it to run it, and then you'll see the main interface of the program.

Load Files

Step 2. Click "Add File(s)" button. Here you can select "Add Video" or "Add Folder" button to add files as you like.

Profile

Step 3. Click the drop-down arrow right beside the "Profile" column and select your desired video format from the drop-down list.

Edit

Step 4. Click "Edit" button to customize the output video like Effect, Trim, Crop, 3D Settings and Watermark.

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