从回调接口获取数据¶
API 提供了 SetStreamCallback()
SetMotionCallback()
函数,来设定各类数据的回调。
注意
一定不要阻塞回调。如果需要长时间处理数据,请将回调作为数据生产者。
参考代码片段:
auto &&api = API::Create(argc, argv);
// Attention: must not block the callbacks.
// Get left image from callback
std::atomic_uint left_count(0);
api->SetStreamCallback(
Stream::LEFT, [&left_count](const api::StreamData &data) {
CHECK_NOTNULL(data.img);
++left_count;
});
// Get depth image from callback
api->EnableStreamData(Stream::DEPTH);
std::atomic_uint depth_count(0);
cv::Mat depth;
std::mutex depth_mtx;
api->SetStreamCallback(
Stream::DEPTH,
[&depth_count, &depth, &depth_mtx](const api::StreamData &data) {
UNUSED(data)
++depth_count;
{
std::lock_guard<std::mutex> _(depth_mtx);
depth = data.frame;
}
});
// Get motion data from callback
std::atomic_uint imu_count(0);
std::shared_ptr<mynteye::ImuData> imu;
std::mutex imu_mtx;
api->SetMotionCallback(
[&imu_count, &imu, &imu_mtx](const api::MotionData &data) {
CHECK_NOTNULL(data.imu);
++imu_count;
{
std::lock_guard<std::mutex> _(imu_mtx);
imu = data.imu;
}
});
api->Start(Source::ALL);
CVPainter painter;
cv::namedWindow("frame");
cv::namedWindow("depth");
unsigned int depth_num = 0;
while (true) {
api->WaitForStreams();
auto &&left_data = api->GetStreamData(Stream::LEFT);
auto &&right_data = api->GetStreamData(Stream::RIGHT);
// Concat left and right as img
cv::Mat img;
cv::hconcat(left_data.frame, right_data.frame, img);
// Draw img data and size
painter.DrawImgData(img, *left_data.img);
// Draw imu data
if (imu) {
std::lock_guard<std::mutex> _(imu_mtx);
painter.DrawImuData(img, *imu);
}
// Draw counts
std::ostringstream ss;
ss << "left: " << left_count << ", depth: " << depth_count
<< ", imu: " << imu_count;
painter.DrawText(img, ss.str(), CVPainter::BOTTOM_RIGHT);
// Show img
cv::imshow("frame", img);
// Show depth
if (!depth.empty()) {
// Is the depth a new one?
if (depth_num != depth_count || depth_num == 0) {
std::lock_guard<std::mutex> _(depth_mtx);
depth_num = depth_count;
// LOG(INFO) << "depth_num: " << depth_num;
ss.str("");
ss.clear();
ss << "depth: " << depth_count;
painter.DrawText(depth, ss.str());
cv::imshow("depth", depth); // CV_16UC1
}
}
char key = static_cast<char>(cv::waitKey(1));
if (key == 27 || key == 'q' || key == 'Q') { // ESC/Q
break;
}
}
api->Stop(Source::ALL);
上述代码,用了 OpenCV 来显示图像和数据。选中显示窗口时,按 ESC/Q
就会结束程序。
完整代码样例,请见 get_from_callbacks.cc 。