Cycles not rendering image or movie clip used as background in the viewport First time I've used cycles rendering engine.  I'm using a movie clip as the background in short animation. Selected RBGA under Property Tab, and Transparent under Film Tab.  It looks good and individual frames in OpenGL active viewport render, and looks fine.

When I try to get it to spit out PNG files of the finished animation the objects render out fine, except no movie clip background as Blender Render engine did when using Paper Sky setting.  Operator error, or am I trying to do something Cycles won't do?  Haven't found an answer in my searches so far.  Can anyone point me in the right direction please. 

Addition:  I think I found my problem after a couple more hours of research.  Post should read "operator ignorance" instead of operator error.  Too tired to try the solution tonight, everything looks better in the morning. Thanks anyway.

Sorry, I just saw your posts.  Really tired.  Much appreciation.
Images (of movie clips) used as background in the 3D viewport are primarily meant to be used as reference and will not render.
Here are a couple of alternatives:

Using the compositor

Add an Input&gt;Movie Clip node, and use an alpha over node to compose the render layers over it.

For single images use an Input&gt;Image node.

If you are using cycles make sure that you enable Film Transparent, so that the rendered layers render with a transparent background:
ver 2.8X and newer

(for ver 2.79 and earlier)


Without the compositor

Without using additional geometry or compositing, you can use the image as background for the world. Set the Texture coordinates to Window.

In this case disable Film&gt;Transparent