Convert m4v to nist

What is the difference between .m4v and .nist?

Description: The M4V file format is a video container format developed by Apple and is very similar to the MP4 format, with the primary difference being the optional Apple Digital Rights Management (DRM) protection. M4V files are commonly used for TV episodes, movies, and music videos in the iTunes Store. These files can be played on Apple devices such as iPhones, iPads, and iPods, as well as on PCs using iTunes or other compatible media players.; SPHERE (SPeech HEader Resources) is a file format defined by NIST (National Institute of Standards and Technology) and is used with speech audio. SoX can read these files when they contain μ-law and PCM data. It will ignore any header information that says the data is compressed using shorten compression and will treat the data as either μ-law or PCM. This will allow SoX and the command line shorten program to be run together using pipes to encompasses the data and then pass the result to SoX for processing.