user12477: I was watching a Twitch.TV stream of a panel of announcers discussing eSports live, and while all of the graphics, sets, backgrounds, lighting looked great, I thought it would be nice if the raw video of the announcers was also processed with composite editing, for a surreal, polished film effect. But I'm not sure: Can a video be composited fast enough to be streamed live, and are there tools capable of doing this?

user10931: The answer is yes, video can be composited fast enough to be streamed live.  The tool that does this is called a switcher.  Typically a switcher introduces a single frame delay from input to composited output.  By connecting the output to a streaming encoder, you can stream out your live, composited video.
For an example, see the Blackmagic Design ATEM System.

12477: <p>I was watching a Twitch.TV stream of a panel of announcers discussing eSports live, and while all of the graphics, sets, backgrounds, lighting looked great, I thought it would be nice if the raw video of the announcers was also processed with composite editing, for a surreal, polished film effect. But I'm not sure: Can a video be composited fast enough to be streamed live, and are there tools capable of doing this?</p>
 10931: <p>The answer is yes, video can be composited fast enough to be streamed live.  The tool that does this is called a switcher.  Typically a switcher introduces a single frame delay from input to composited output.  By connecting the output to a streaming encoder, you can stream out your live, composited video.</p>

<p>For an example, see the Blackmagic Design <a href="https://www.blackmagicdesign.com/products/atem" rel="nofollow">ATEM System</a>.</p>
