devela::_dep::sdl3::sys::camera

Function SDL_OpenCamera

pub unsafe extern "C" fn SDL_OpenCamera(
    instance_id: u32,
    spec: *const SDL_CameraSpec,
) -> *mut SDL_Camera
Available on crate feature dep_sdl3 only.
Expand description

Open a video recording device (a “camera”).

You can open the device with any reasonable spec, and if the hardware can’t directly support it, it will convert data seamlessly to the requested format. This might incur overhead, including scaling of image data.

If you would rather accept whatever format the device offers, you can pass a NULL spec here and it will choose one for you (and you can use SDL_Surface’s conversion/scaling functions directly if necessary).

You can call SDL_GetCameraFormat() to get the actual data format if passing a NULL spec here. You can see the exact specs a device can support without conversion with SDL_GetCameraSupportedFormats().

SDL will not attempt to emulate framerate; it will try to set the hardware to the rate closest to the requested speed, but it won’t attempt to limit or duplicate frames artificially; call SDL_GetCameraFormat() to see the actual framerate of the opened the device, and check your timestamps if this is crucial to your app!

Note that the camera is not usable until the user approves its use! On some platforms, the operating system will prompt the user to permit access to the camera, and they can choose Yes or No at that point. Until they do, the camera will not be usable. The app should either wait for an [SDL_EVENT_CAMERA_DEVICE_APPROVED] (or [SDL_EVENT_CAMERA_DEVICE_DENIED]) event, or poll SDL_GetCameraPermissionState() occasionally until it returns non-zero. On platforms that don’t require explicit user approval (and perhaps in places where the user previously permitted access), the approval event might come immediately, but it might come seconds, minutes, or hours later!

§Parameters

  • instance_id: the camera device instance ID.
  • spec: the desired format for data the device will provide. Can be NULL.

§Return value

Returns an SDL_Camera object or NULL on failure; call SDL_GetError() for more information.

§Thread safety

It is safe to call this function from any thread.

§Availability

This function is available since SDL 3.2.0.

§See also