I am looking for ideas on how to achieve the following:
1. A video camera streams feed continuously, but it is not recorded
2. An event occurs - e.g a door is opened, triggering a switch
3. The video from 30s before the event and up to 30s after the event is captured and saved to disk
4. The system waits for any subsequent events and repeats the process.
The video stream is going to be VGA standard at 25fps - any hints?