Marvel Studios hasn't released any footage other than special trailers for various conventions, and the only thing the general public has seen is leaked images and gifs.
It's possible Disney/Marvel may have learned from Avengers: Age Of Ultron that you don't have to release three-quarters of the movie online prior to the release as not only has the Captain America: Civil War trailer not been released, but J.J. Abrams has also released only a limited amount of Star Wars: The Force Awakens material.
Regarding Avengers 2, really the only footage that wasn't released prior to the movie was the film's conclusion. A majority of us online follow all the news rather closely, so if you watched all the Age Of Ultron spots and trailers, it's a good bet the movie was spoiled for you, which may have resulted in a disappointing or lackluster viewing (raises hand).
There is a rumor going around that the Captain America: Civil War trailer is being attached to Sony's James Bond Spectre; however, according to Collider that isn't true.
It's also pointed out that the potential Russo Bros. Twitter account tweeted out a pic from a Star Wars poster, which in essence is confirming the Captain America: Civil War trailer with Star Wars: The Force Awakens in December.
Of course, the tweet could also be hinting at Taskmaster, but who knows.
"Star Wars: The Force Awakens" hits December 18th.
"Captain America: Civil War" has a May 6, 2016 release date directed by Anthony and Joe Russo starring Chris Evans, Robert Downey Jr., Scarlett Johansson, Jeremy Renner, Elizabeth Olsen, Sebastian Stan, Anthony Mackie, Frank Grillo, Paul Bettany, Don Cheadle, Emily VanCamp, William Hurt, Martin Freeman and Chadwick Boseman as Black Panther.
Captain America: Civil War picks up where Avengers: Age of Ultron left off, as Steve Rogers leads the new team of Avengers in their continued efforts to safeguard humanity. After another international incident involving the Avengers results in collateral damage, political pressure mounts to install a system of accountability and a governing body to determine when to enlist the services of the team. The new status quo fractures the Avengers while they try to protect the world from a new and nefarious villain.