Scramble/Encrypt/Protect MP4 or other popular types of video?

[gilius2k14]

I'm looking for a way to encrypt a video that scrambles the picture with the possibility of unscrambling based on, say, an encryption key?

This is different from zipping up a file as I want to be able to play back the video in a scrambled state without the video player knowing that it's encrypted.

It's kind of similar to DRM protection, but should ideally require decoding before the picture displays correctly.

Any ideas if such a thing exists? If not then which software is used for DRM protection and is it free?

[Cornucopia]

Sentence 2 makes no sense. Every player that works with DRM and encryption KNOWS it and has to do many things behind the scenes in order for the file to be decrypted, decoded and displayed, in real time.

What you're describing IS drm. And all successful forms of drm are the opposite of free.

Scott

[LigH.de]

Some of you may have noticed that Microsoft abandoned Zune. Now all the music you once bought for this DRM system, you wasted your money on. Please buy another copy for another DRM system.

So who would possibly want DRM? Certainly not even one consumer with a minimum of common sense.