This video shows two extremely fast objects passing in front of a single engine aircraft. It was shot in Argentina in 2017. It is not a computer graphic and the objects are moving too fast to be ordinary drones or birds. That leaves unknown objects. But there are questions: why did the pilot happen to be filming at just that moment? Was he hanging a cellphone out of the cockpit? Why? There is no indication that the camera follows the fast-moving objects, but that actually adds to the possibility that this might be authentic. The object would almost certainly not have been picked up by the naked eye, especially in a windy cockpit.
This video records a possible unknown.https://www.youtube.com/watch?v=ae1DiT8Hs4k