Dealing with webcams that are offline

I love the plugin however there is one issue, if the webcam I am pointing to is offline e.g down for maintenance I just get a broken image, what would be great would be a function to allow a previously captured image to be be substituted so I could add some text, or just the text “Offline” so I don’t get a broken appearance, other than that great plugin

https://www.ads-software.com/plugins/netcam-live-stream/