Multiple Simultaneous Live Video Streams
Live Control Room mode may be the most appealing option for true Olympics junkies. It lets you view up to four live streams of video at once, via one primary window and three smaller picture-in-picture windows. The primary video in this mode is presented at 320-by-176-pixel resolution, with a 350-kbps video stream; picture-in-picture views are presented at 128-by-96-pixel resolution, with a 50-kbps video stream.
Presenting multiple simultaneous video streams in the Live Control Room is a twofold technical challenge, says Matthew Rechs, chief technology officer at Schematic, the company that built the NBC player and that has also worked on presenting interactive content on HD DVD movie discs. "When we have multiple video images on the same screen, we have to add up the bit rates to see how much bandwidth it will take to display all of that video simultaneously, without impacting the system's performance," says Rechs. "You want to intelligently manage the total bandwidth available and distribute that across the various images. There are different modes for video playback, and each mode has different bit rates available to it."
The third mode, Popup, has a smaller interface that you can keep next to open work documents while you are at the office. The basic Popup player runs at 592-by-336-pixel resolution, with a 650-kbps stream for live events and a 1.1-mbps stream for on-demand events.
Silverlight's ability to handle text data and video helps the NBC player break with the standard design of media players that display video in your browser window. For example, with YouTube, you have a media player in one quadrant of the browser and supplemental info in other quadrants; the sections are not necessarily integrated or tied together. "Silverlight will make the player look more like a TV experience, and less like a data experience," Miller promises.
With the NBC Olympics player, the user interface leaves the Web browser window and enters the player itself, as navigation icons and extra content appear within the player window. You can obtain additional info--for example, athlete biographies tied to the competition you're watching--from within the player.
In all, eight video streams will be available for live video and six for on-demand video. And according to Rechs, the possible player and video stream permutations are so numerous that video can't be encoded natively for each scenario; instead, a video stream may be delivered at a resolution different from the one that the playback window is designed to use. "In these cases, we are shrinking or stretching the video slightly at playback time, but we have done extensive testing to ensure the integrity of the video image," says Rechs. The Silverlight player will automatically pick the right stream to present, given your bandwidth and your viewing choice.
Where the Content Will Come From
According to NBC, the video available for playback will hail from a mix of sources, including feeds from the International Olympic Committee's international pool of broadcasts, NBC's cameras, and NBC's studio commentary operations in Stamford, Connecticut, and at its New York City facilities.
Though the player application was still under development two months before the start of the Games, NBC officials described some of the more-impressive plans for the project. After a competition concludes, for example, you'll be able to click on the name of an athlete listed in the competition results and then view the athlete's performance at your leisure.
"We're assigning metadata with all of the video, so as the athletes perform, we're syncing up the metadata of their results with the time code of the video," says Miller. For example, while watching a recorded gymnastics video, you'll be able to navigate to the winning moment even while scrolling through athletes' biographies or through competition results. The same approach will be used to assemble the on-demand reels of highlights.
Naturally, NBC's hopes that these digital highlight reels--along with expanded profiles of the athletes--will attract new viewers to these sports, as well as encouraging fans to tune in to more coverage online or on TV.
Given the immense scale of this project, NBC has taken various precautions with regard to server infrastructure to ensure that it's prepared to handle the anticipated load of online viewers. "We've spent a great deal of time with Microsoft and their networking teams, since they're hosting our video," says Miller.
Mobile Streaming Video Planned
Access to NBC's multimedia streaming won't be limited to desktop PCs. NBC will have a dedicated live-streaming mobile channel, NBC-to-Go, that will carry feeds from NBC's television networks. However, the channel will be available only on AT&T cellular phones. Don't have an AT&T phone? Then you won't be able to watch live feeds--but you can access video highlights of various events via a WAP (Wireless Access Protocol) version of NBCOlympics.com on any WAP-enabled cellular phone.
Also in the works as of press time: NBC Olympics On-the-Go, which is designed to enable you to take prerecorded video content with you for viewing on your laptop when you travel.