CouchPotato is a command-line utility that can be used to capture Real Time Streaming Protocol or H.264 video streams, typically from a networked cameras.
It can be run from outside the network, provided that there is no block on the place from where it is being run. Else, one needs to run it from a machine within a network.
The tool can save what it collects either as still images provided an image in one frame differs from a previously captured frame or as a stream in the .avi format.
The documentation says that the image hashing algorithm pHash is incorporated into ffmpeg's image2 demuxer to provide image change detection capabilities.
CouchPotato has to be launched in an ICE v3 Fire and Collect compatible loader.