Welcome back to ABC's Oscar headquarters. Imagine the pressure of an Oscar host. With a worldwide audience of hundreds of millions of people, it's high stakes for this year's academy awards. The one... See More
Welcome back to ABC's Oscar headquarters. Imagine the pressure of an Oscar host. With a worldwide audience of hundreds of millions of people, it's high stakes for this year's academy awards. The one and only Ellen DeGeneres. Robin Roberts sat down with the woman leading the show. She said she's going to step up her game. But how? It's one of the catchiest Oscar announcements in years. Fun, lively, and oh, so Ellen DeGeneres. Strutting in a tux and her hallmark tennis shoes. But make no mistake. The pressure is on Ellen. What's it look to look up and see yourself. That's normally in my yard. I moved it here to help them out. We just tweaked it and said oscars. Driving here is the first time I saw it and it's enormous. Indeed. This will be Ellen's second time hosting the oscars. Do you mind if I get a picture with you. Make sure we're both in, Steven. Reporter: Her upcoming performances places her in a pantheon alongside soft of the best actors in history. Steve martin to Billy crystal. With some 40 million people watching, it's a light hearted role she does not take lightly. It will be fun and silly in some parts, but it should be honored and it should be classy and respected. It's not a standup gig. It's the oscars. I do take it seriously. This is a big deal. It's the oscars, by golly. If I don't take it seriously, it's disrespectful. This is an institution, this is the 86th year. The first year they did it people were probably in their living rooms going someone should invent TV. You've got to have this musicality, theatricality to be an Oscar host. It's hard to pull it off and be successful. Others who have stepped in have delivered some memorable highs and, well, lows. Who would forget nine-time Oscar host Billy crystal's infamous Hannibal lecter skit in 1992. I'm having some of academy over for dinner. Care to join me? Whoopi Goldberg was the first woman and the first african-american to host solo. There haven't been this many women sweating over one woman since Heidi flies. Antihathaway and James Franco caught flak. I must say you look so beautiful and so hip. Oh, thank you, James. You look very appealing to a younger demographic as well. They had to go into hiding. People hated their hosting so much. Last year, Seth Mcfarlane's humor left some dumb struck. Kristen Stewart you saw your boobs. And monster, we saw charlicharliz Charlize Theron's. You know what they say. Three time is a charm. Twha? It's my second time? I want people to relax and I want people to have fun and I want people to think that three and a half hours went by like that. It's a hallmark style that comes to define her in her wildly popular talk show now in its 11th season. But Ellen says despite all her TV hosting experience, hosting the oscars is more terrifying than anything else. Hosting this is like bungee jumping. But you're in front of an audience all the time. What's the difference? It's not about me. I should be good enough that people talk the next day and go she was great. But I shouldn't stand out enough that it overshadows anything. Preparing for the larger stage, she say, is a welcome challenge. It's a different caliber of everything. I got to step it up. How are rehearsals going? Now I'm wornging on what I'm doing through the whole show. Isle be in the audience a lot. It's never been my humor to get a laugh at anyone el's expense. It's never going to be a mean joke. After last year's edgy but criticized host, Ellen is setting a difference course. My intentions are to make people happy and my intentions are to have compassion. How is Ellen expected to do in her Oscar encore? She keeps things loose and fun and fresh. I think Ellen is going to be a great host. I think she's going to knock it out of the park. She says she's honored to be part of Oscar's history. I established more than I I could have ever dreamt to accomplish in my life. Reporter: For "Nightline" I'm robin Roberts in Hollywood.
This transcript has been automatically generated and may not be 100% accurate.