Determines how much space (in btyes) is available to save video files to the camera roll.
camera_error_t camera_roll_available_video(camera_handle_t handle, long long *size)
The handle to the camera.
A pointer that is updated with the number of bytes available for saving the video.
The size argument is updated with the amount of space in bytes.
CAMERA_OK when the function successfully completes, otherwise another camera_error_t value that provides the reason that the call failed.