Img_3147.m4v
Download VLC Media Player . It is free, open-source, and plays almost any file format without needing extra codecs.
Here is a blog-style guide on how to handle files like . What is an .M4V file? IMG_3147.M4V
Use a tool like Handbrake to re-encode the video into a standard MP4 format. Why is my computer showing this name? Download VLC Media Player
Surprisingly, you can often just change the extension from .m4v to .mp4 manually, and most players will still read it. IMG_3147.M4V