How does `ICameraProvider::getCameraDevices` working?

[yuanyue11681]

Hi everyone, I think ICameraProvider::getCameraDevices is a pure virtual function, the declaration is

class ICameraProvider : public Interface {
     public:
         ....
         virtual Status getCameraDevices(std::vector<CameraDevice*>* devices) const = 0;
         ...
 };

but I saw some code in /usr/src/jetson_multimedia_api/samples/13_multi_camera/main.cpp like

    g_cameraProvider = UniqueObj<CameraProvider>(CameraProvider::create());
    ICameraProvider *iCameraProvider = interface_cast<ICameraProvider>(g_cameraProvider);
    ....
    std::vector<CameraDevice*> cameraDevices;
    iCameraProvider->getCameraDevices(&cameraDevices);
    if (cameraDevices.size() == 0)
        ORIGINATE_ERROR("No cameras available");

The interface_cast seem do something like cast CameraProvider to its parent class InterfaceProvider, then get Interface and cast to ICameraProvider , some abstract class cast things…

I don’t understand, how does the getCameraDevices( a pure virtual function) really working, where is its implement ?

[ShaneCCC]

It’s implement in the libnvargus.so that didn’t public the source code.

[yuanyue11681]

thank you for your reply