I have shown this video before and it is an actual Mass Hollywood filmed for an actual movie. It is a small portion of "The Mass of the Ages," taken from the Deanna Durbin feature film, "Christmas Holiday." It was filmed at the former Los Angeles Cathedral, Saint Vibiana which was severely damaged by an earthquake. Even Protestants and secularists and non believers found this form of the Mass quite beautiful. It was quite the evangelizer!
What is stunning is that so much of this Christmas Midnight Mass is incorporated into the movie!
And please note that the communicants begin to approach the altar railing exactly at the point the priest is receiving His Holy Communion to complete the Sacrifice. Thus by the time the Confiteor is chanted for the congregation, communicants are kneeling at the altar railing and others are standing in the aisle. As soon as the priest turns toward them for the absolution, even those in the asile will kneel for it and the Ecce Agnus Dei and their Domini Non Sum dignus.
This is how I recall communicants approaching the railing prior to Vatican II!