What needs to happen is a few things.
- When the SD card is removed OR added, then send a notification. Also, if after a power off and on the SD card changed between. Then send a notification.
- If the power is out for 5 min or the cam can’t see the net for 5 min, then send a notification. Once it can, then let the owner know (similar to smartthings)
For 1, the reason you want to know when one is added or changed is cyber security along with you might of not of put the SD card in their to start with.
If you actually have a buffering period when events happen. I doubt it, but it might be possible to actually have an image of what happen before the power problem. But realistically, the best way to handle this is by when it disconnects from the net. Where when the camera isn’t seen by the servers for more than 5 min, you will be notified. And then have it where you are notified when the camera comes back online.
But it might be possible to have it where if there is a buffering in the system. When the camera loses power, it detects this and quickly saves the last frames and timestamp. Then when the camera comes back on, it sends this out to the user as a notification. Even if saving a picture isn’t possible, it lets the user know the camera lost power and came back and the times.