We currently create an iterator count the number of entries to returns to compute the number of entries a database stores.

There is a better way that is not O(n) which is using the num_entries field of the Stat struct that is returned by [the mdb_stat function](https://

Let's consider the code:

...
lirs::V4L2VideoCapture capture("/dev/video0", ...);
if (capture.IsOpened()) {
    capture.StartStreaming();
    // formats, frame, etc. rate are negotiated, buffers are allocated
    capture.Set(lirs::CaptureParams::FPS, 60);   // change the frame
}

In the code above frame rate is being changed during streaming process.
Currently, this change wil