Determines how much space (in bytes) is available for new video files on the camera roll
#include <camera/camera_api.h>
camera_error_t camera_roll_available_video(camera_handle_t handle, long long *size)
The size argument is updated with the amount of free space in bytes.
CAMERA_EOK when the function successfully completes, otherwise another camera_error_t value that provides the reason that the call failed.