How hard (and expensive) would it be to copy-protect a 15MB MP4 video sold as a download off a web site? Admittedly, this isn't my area -- I make video, not sell it. I'd like to do what the iTunes Music Store does, which is sell content to play on a limited number (four or five) devices/computers.

Any information is greatly appreciated!

T.J.

I'm not an expert - far from it but what your asking doesn't exsist easily as far as i know.

The only way to have a form of copy protection that I know that anyone (kinda) do is WMV with DRM.

itunes doesn't let people sell unless your big - at least i've never heard any independants get videos on it. WMV allows you to setup a DRM server or get someone else to host the DRM server and every time you play the file it checks the DRM server. WMV with DRM isn't cross plateform as far as i know and requires a windows server computer with DRM server extensions.

So in short, i don't know of a way that can do the DRM your looking for easily or at the file level. If someone does it would be awesome to hear about it.

EDIT:

I suggested this before but use the online pornography companies as an example. The easiest way to do this is to setup a streaming server and have a members area. They can't save (unless they are really smart) but can watch as much as they want - at the cost of a server and bandwidth

Thanks, Keith. That's what I was afraid of :(

the porno companies are so good with drm these days that they charge by the minute, lol... and i think that it's all wmv.

when you say mp4, are you referring to h.264? great codec... if you must have mp4, how about the fairplay drm that apple uses?