Cling MediaRenderer Screenshots
The following snapshot shows the Cling MediaRenderer window on the top:

For debugging you can expand the logger panel as shown, or minimize the application when you only want to watch video or have music streamed to the renderer in the background.
At the bottom there are two videos playing, the instance identifiers are "0" and "1", respectively. The first instance plays the the Big Buck Bunny trailer from a local source. The renderer understands file://... URLs, so you can instruct it to play a file that is available on the local filesystem. This also works if you want to mount your media through SMB, when you don't have a UPnP/DLNA compatible MediaServer.
The second instance is playing a continous Motion-JPEG stream with 24 fps from an Axis web/security camera. The image data is streamed over an HTTP transport.

