Try to capture from arducam on RPI as fast as possible.

capture_fast.cpp

#include "arducam_mipicamera.h"
#include <linux/v4l2-controls.h>
#include <stdio.h>
#include <sys/time.h>

void capture_image(CAMERA_INSTANCE camera_instance) {
    IMAGE_FORMAT fmt = {IMAGE_ENCODING_RAW_BAYER, 0};
    BUFFER *buffer = arducam_capture(camera_instance, &fmt, 6000);
    arducam_release_buffer(buffer);
}

unsigned long long millis() {
    struct timeval tv;
    gettimeofday(&tv, NULL);
    return (unsigned long long)(tv.tv_sec) * 1000 +
        (unsigned long long)(tv.tv_usec) / 1000;
}

int main(int argc, char **argv) {
    CAMERA_INSTANCE camera_instance;
    int width = 4656, height = 3496;
    unsigned int n = 20;

    arducam_init_camera(&camera_instance);
    arducam_set_resolution(camera_instance, &width, &height);
    arducam_software_auto_exposure(camera_instance, 0);
    arducam_software_auto_white_balance(camera_instance, 1);
    arducam_set_control(camera_instance, V4L2_CID_EXPOSURE, 200);
    arducam_set_control(camera_instance, V4L2_CID_FOCUS_ABSOLUTE, 100);
    arducam_write_sensor_reg(camera_instance, 0x0307, 74);

    // first image capture is slow
    capture_image(camera_instance);

    unsigned long long start = millis();
    for (int i = 0; i < n; i++) {
        capture_image(camera_instance);
    }
    unsigned long long end = millis();
    float duration = end - start;
    printf("average duration: %f ms\n", duration / n);
    printf("average framerate: %f fps\n", 1000 * n / duration);

    arducam_close_camera(camera_instance);

    return 0;
}