There are two kinds of videoio backends: built-in backends and plugins which will be loaded at runtime (since OpenCV 4.1.1). Use functions cv::videoio_registry::getBackends, cv::videoio_registry::hasBackend and cv::videoio_registry::getBackendName to check actual presence of backend during runtime.
There are two kinds of videoio backends: built-in backends and plugins which will be loaded at runtime (since OpenCV 4.1.0). Use functions cv::videoio_registry::getBackends, cv::videoio_registry::hasBackend and cv::videoio_registry::getBackendName to check actual presence of backend during runtime.
To enable built-in videoio backends:
To enable built-in videoio backends:
1. Enable corresponding CMake option, e.g. `-DWITH_GSTREAMER=ON`
1. Enable corresponding CMake option, e.g. `-DWITH_GSTREAMER=ON`