camera_feedback.cpp

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/**
 * @file camera_feedback.cpp
 *
 * Online and offline geotagging from camera feedback
 *
 * @author Mohammed Kabir <kabir@uasys.io>
 */

#include "camera_feedback.hpp"

namespace camera_feedback
{
CameraFeedback  *g_camera_feedback;
}

CameraFeedback::CameraFeedback() :
    _task_should_exit(false),
    _main_task(-1),
    _trigger_sub(-1),
    _gpos_sub(-1),
    _att_sub(-1),
    _capture_pub(nullptr),
    _camera_capture_feedback(false)
{

    // Parameters
    _p_camera_capture_feedback = param_find("CAM_CAP_FBACK");

    param_get(_p_camera_capture_feedback, (int32_t *)&_camera_capture_feedback);

}

CameraFeedback::~CameraFeedback()
{

    if (_main_task != -1) {

        /* task wakes up every 100ms or so at the longest */
        _task_should_exit = true;

        /* wait for a second for the task to quit at our request */
        unsigned i = 0;

        do {
            /* wait 20ms */
            px4_usleep(20000);

            /* if we have given up, kill it */
            if (++i > 50) {
                px4_task_delete(_main_task);
                break;
            }
        } while (_main_task != -1);
    }

    camera_feedback::g_camera_feedback = nullptr;
}

int
CameraFeedback::start()
{

    /* start the task */
    _main_task = px4_task_spawn_cmd("camera_feedback",
                    SCHED_DEFAULT,
                    SCHED_PRIORITY_DEFAULT + 15,
                    1600,
                    (px4_main_t)&CameraFeedback::task_main_trampoline,
                    nullptr);

    if (_main_task < 0) {
        warn("task start failed");
        return -errno;
    }

    return OK;

}

void
CameraFeedback::stop()
{
    if (camera_feedback::g_camera_feedback != nullptr) {
        delete (camera_feedback::g_camera_feedback);
    }
}


void
CameraFeedback::task_main()
{
    _trigger_sub = orb_subscribe(ORB_ID(camera_trigger));

    // Polling sources
    struct camera_trigger_s trig = {};

    px4_pollfd_struct_t fds[1] = {};
    fds[0].fd = _trigger_sub;
    fds[0].events = POLLIN;

    // Geotagging subscriptions
    _gpos_sub = orb_subscribe(ORB_ID(vehicle_global_position));
    _att_sub = orb_subscribe(ORB_ID(vehicle_attitude));
    struct vehicle_global_position_s gpos = {};
    struct vehicle_attitude_s att = {};

    bool updated = false;

    while (!_task_should_exit) {

        /* wait for up to 20ms for data */
        int pret = px4_poll(&fds[0], (sizeof(fds) / sizeof(fds[0])), 20);

        if (pret < 0) {
            PX4_WARN("poll error %d, %d", pret, errno);
            continue;
        }

        /* trigger subscription updated */
        if (fds[0].revents & POLLIN) {

            orb_copy(ORB_ID(camera_trigger), _trigger_sub, &trig);

            /* update geotagging subscriptions */
            orb_check(_gpos_sub, &updated);

            if (updated) {
                orb_copy(ORB_ID(vehicle_global_position), _gpos_sub, &gpos);
            }

            orb_check(_att_sub, &updated);

            if (updated) {
                orb_copy(ORB_ID(vehicle_attitude), _att_sub, &att);
            }

            if (trig.timestamp == 0 ||
                gpos.timestamp == 0 ||
                att.timestamp == 0) {
                // reject until we have valid data
                continue;
            }

            struct camera_capture_s capture = {};

            // Fill timestamps
            capture.timestamp = trig.timestamp;

            capture.timestamp_utc = trig.timestamp_utc;

            // Fill image sequence
            capture.seq = trig.seq;

            // Fill position data
            capture.lat = gpos.lat;

            capture.lon = gpos.lon;

            capture.alt = gpos.alt;

            capture.ground_distance = gpos.terrain_alt_valid ? (gpos.alt - gpos.terrain_alt) : -1.0f;

            // Fill attitude data
            // TODO : this needs to be rotated by camera orientation or set to gimbal orientation when available
            capture.q[0] = att.q[0];

            capture.q[1] = att.q[1];

            capture.q[2] = att.q[2];

            capture.q[3] = att.q[3];

            // Indicate whether capture feedback from camera is available
            // What is case 0 for capture.result?
            if (!_camera_capture_feedback) {
                capture.result = -1;

            } else {
                capture.result = 1;
            }

            int instance_id;

            orb_publish_auto(ORB_ID(camera_capture), &_capture_pub, &capture, &instance_id, ORB_PRIO_DEFAULT);

        }

    }

    orb_unsubscribe(_trigger_sub);
    orb_unsubscribe(_gpos_sub);
    orb_unsubscribe(_att_sub);

    _main_task = -1;

}

int
CameraFeedback::task_main_trampoline(int argc, char *argv[])
{
    camera_feedback::g_camera_feedback->task_main();
    return 0;
}

static int usage()
{
    PX4_INFO("usage: camera_feedback {start|stop}\n");
    return 1;
}

extern "C" __EXPORT int camera_feedback_main(int argc, char *argv[]);

int camera_feedback_main(int argc, char *argv[])
{
    if (argc < 2) {
        return usage();
    }

    if (!strcmp(argv[1], "start")) {

        if (camera_feedback::g_camera_feedback != nullptr) {
            PX4_WARN("already running");
            return 0;
        }

        camera_feedback::g_camera_feedback = new CameraFeedback();

        if (camera_feedback::g_camera_feedback == nullptr) {
            PX4_WARN("alloc failed");
            return 1;
        }

        camera_feedback::g_camera_feedback->start();
        return 0;
    }

    if (camera_feedback::g_camera_feedback == nullptr) {
        PX4_WARN("not running");
        return 1;

    } else if (!strcmp(argv[1], "stop")) {
        camera_feedback::g_camera_feedback->stop();

    } else {
        return usage();
    }

    return 0;
}