Create image without a camera device

[Eugeny1]

This is suggestion.

Rationale: when cam has been disconnected or failed (no device which can be used) I need a picture saying "NO CAMERA" or "CAMERA FAILED" with title/subtitle/current timestamp/info as usual. It may technically be created by just specifying png file as "input device" which will then appear in the place of camera image. Thus the job is to open the "device" and see if it is device file or regular file, if it is regular file, do not touch any physical device and just copy image into the output. Resizing/cropping and other effects must still apply as usual for the image. Doable?