I use the sensor ov7740 and f429 (and h743 (openmv4)).
I compiled your project under f429 (openmv2).
But I do not get an interrupt HAL_DCMI_FrameEventCallback().
The h743 have this interrupt.

What could be the problem?

Hi, we don’t provide support for you building the system on your own using different parts. An infinite amount of things could be wrong. You need to be good enough to debug the system on your own if you are doing this.