megapixels/tools/test_camera.c

#include "camera.h"
#include "device.h"
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

double get_time()
{
    struct timeval t;
    struct timezone tzp;
    gettimeofday(&t, &tzp);
    return t.tv_sec + t.tv_usec*1e-6;
}

void on_capture(MPImage image, void *user_data)
{
    size_t num_bytes = mp_pixel_format_width_to_bytes(image.pixel_format, image.width) * image.height;
    uint8_t *data = malloc(num_bytes);
    memcpy(data, image.data, num_bytes);

    printf("      first byte: %d.", data[0]);

    free(data);
}

int main(int argc, char *argv[])
{
    if (argc != 2 && argc != 3) {
        printf("Usage: ./test_camera <media_device_name> [<sub_device_name>]\n");
        return 1;
    }

    char *video_name = argv[1];
    char *subdev_name = NULL;
    if (argc == 3) {
        subdev_name = argv[2];
    }

    double find_start = get_time();

    // First find the device
    MPDevice *device = mp_device_find(video_name);
    if (!device) {
        printf("Device not found\n");
        return 1;
    }

    double find_end = get_time();

    printf("Finding the device took %fms\n", (find_end - find_start) * 1000);

    int video_fd;
    uint32_t video_entity_id;
    {
        const struct media_v2_entity *entity = mp_device_find_entity(device, video_name);
        if (!entity) {
            printf("Unable to find video device interface\n");
            return 1;
        }

        video_entity_id = entity->id;

        const struct media_v2_interface *iface = mp_device_find_entity_interface(device, video_entity_id);

        char buf[256];
        if (!mp_find_device_path(iface->devnode, buf, 256)) {
            printf("Unable to find video device path\n");
            return 1;
        }

        video_fd = open(buf, O_RDWR);
        if (video_fd == -1) {
            printf("Unable to open video device\n");
            return 1;
        }
    }

    int subdev_fd = -1;
    if (subdev_name)
    {
        const struct media_v2_entity *entity = mp_device_find_entity(device, subdev_name);
        if (!entity) {
            printf("Unable to find sub-device\n");
            return 1;
        }

        const struct media_v2_pad *source_pad = mp_device_get_pad_from_entity(device, entity->id);
        const struct media_v2_pad *sink_pad = mp_device_get_pad_from_entity(device, video_entity_id);

        // Disable other links
        const struct media_v2_entity *entities = mp_device_get_entities(device);
        for (int i = 0; i < mp_device_get_num_entities(device); ++i) {
            if (entities[i].id != video_entity_id && entities[i].id != entity->id) {
                const struct media_v2_pad *pad = mp_device_get_pad_from_entity(device, entities[i].id);
                mp_device_setup_link(device, pad->id, sink_pad->id, false);
            }
        }

        // Then enable ours
        mp_device_setup_link(device, source_pad->id, sink_pad->id, true);

        const struct media_v2_interface *iface = mp_device_find_entity_interface(device, entity->id);

        char buf[256];
        if (!mp_find_device_path(iface->devnode, buf, 256)) {
            printf("Unable to find sub-device path\n");
            return 1;
        }

        subdev_fd = open(buf, O_RDWR);
        if (subdev_fd == -1) {
            printf("Unable to open sub-device\n");
            return 1;
        }
    }

    double open_end = get_time();

    printf("Opening the device took %fms\n", (open_end - find_end) * 1000);

    MPCamera *camera = mp_camera_new(video_fd, subdev_fd);

    MPCameraModeList *modes = mp_camera_list_available_modes(camera);

    double list_end = get_time();

    printf("Available modes: (took %fms)\n", (list_end - open_end) * 1000);
    for (MPCameraModeList *mode = modes; mode; mode = mp_camera_mode_list_next(mode)) {
        MPCameraMode *m = mp_camera_mode_list_get(mode);
        printf("  %dx%d interval:%d/%d fmt:%s\n", m->width, m->height, m->frame_interval.numerator, m->frame_interval.denominator, mp_pixel_format_to_str(m->pixel_format));

        if (m->frame_interval.denominator < 15 || m->frame_interval.denominator > 30) {
            printf("    Skipping…\n");
            continue;
        }

        double start_capture = get_time();

        mp_camera_set_mode(camera, m);
        mp_camera_start_capture(camera);

        double last = get_time();
        printf("    Testing 10 captures, starting took %fms\n", (last - start_capture) * 1000);

        for (int i = 0; i < 10; ++i) {
            mp_camera_capture_image(camera, on_capture, NULL);

            double now = get_time();
            printf(" capture took %fms\n", (now - last) * 1000);
            last = now;
        }

        mp_camera_stop_capture(camera);
    }

    double cleanup_start = get_time();

    mp_camera_free(camera);

    close(video_fd);
    if (subdev_fd != -1)
        close(subdev_fd);

    mp_device_close(device);

    double cleanup_end = get_time();

    printf("Cleanup took %fms\n", (cleanup_end - cleanup_start) * 1000);
}