Recording to a circular stream

On the Raspberry Pi you have a feature to keep an in-memory stream containing the last x seconds of video recorded. A typical use-case for this sort of storage would be an external event triggered by a GPIO input event which will trigger OpenMV to store the 5 seconds prior to and 5 seconds after the GPIO event. Has anyone done such an implementation? Any available examples?

We don’t have enough ram to do that. Maybe in future versions of the product. We have been wanting to build a version of the system which has DRAM. But, as we are a bootstrapped company without any major investment we can’t add RAM to the system because of the BOM increase that would occur. We are thinking about building a higher end (and higher cost camera) that would have these features however as cost is the main reason for our current build simplicity.

Note that OpenMV has very low latency compared to RPi.