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Metadata Spec Will Add VOD Tools

As cable on-demand systems grow increasingly sophisticated, metadata — the electronic librarian that maintains those systems’ virtual video card catalog — is playing a larger and more significant role than ever before. To keep pace, cable operators and content providers will soon have an expanded set of metadata tools thanks to new video-on-demand specification guidelines recently issued by CableLabs Inc.

Metadata refers to information related to a digital-video file apart from the video image itself. In the early days of VOD services, that was as simple as the title of the video. But it has since evolved to include a whole slew of critical information about content, from what descriptive text should be sent to the electronic programming guide, what search engine keywords should be associated with it, how long a video title is available for viewing and whether it can be digitally copied.

Fortunately for programmers like Home Box Office, in the U.S. there are consistent rules about on-demand metadata thanks to specifications issued by CableLabs, the industry’s technology consortium.

In fact, when VOD services were just getting off the ground several years ago, Time Warner Cable, HBO and several other cable players got together and came up with uniform guidelines that served as the basis for the original CableLabs Video-On-Demand Metadata specification.

Metadata is critical to drive on-demand services as they evolve, said Bob Zitter, HBO executive vice president and technology officer.

“In the old days, television was just video and audio,” Zitter said. “Now it is video, audio and metadata. The metadata provides information for the devices that handle television — and those devices may be in cable headends and they might be in the consumers’ homes.”


In April, CableLabs issued its new Video-On-Demand Metadata Content Specification 2.0 guidelines, adding several upgrades that will make it easier to knit together on-demand and standard TV search engines, as well as make it easier to insert ads and attach more descriptive information about a video title.

One key upgrade under VOD Metadata 2.0 separates the video from metadata assigned to it, allowing operators to better mix and match content.

Under the current system, if an operator wants to repackage a movie as part of a double-feature, the movie must be reprocessed and resaved to the server. Using Metadata 2.0, the content and metadata are stored as separate files, so when the movie is repackaged, only the metadata is changed, not the video. It also allows the operator to add a new trailer to an existing movie without having to resave the original file.

“Therefore, you can pitch that once and have it in the cable system, and then if you need to create different types of titling structures you can send the metadata and just attach it to the content,” said Yasser Syed, CableLabs project director for the metadata specification.

That also plays into the licensing window for video files. With Metadata 2.0, operators could offer a movie at a special price on Friday night, and then charge the original price on Saturday — again, by changing the metadata but not the video file. Or they could supply programming guide information about a title in several languages via multiple metadata files.

The reverse is also true. If a cable operator wants to create a video in high-definition and standard-definition versions, the two files can be assigned the same metadata file supplying information such as title descriptions and copyrights.

Most of the metadata improvements offered under the new specification will not be noticeable by the customer, but one place where they will see a change is the addition of chaptering similar to that of DVDs, according to C-COR senior vice president of global technology strategy Joe Matarese.


“We [now] have the ability to do what they have been able to do on DVDs for a while — allowing our subscribers to select where in a piece of content or what portion of the content they want to view,” Matarese said. “It also gives the ability to create playlists that contain multiple segments each, within a piece of content. We can create those playlists now to allow more sophisticated presentation of content in front of subscribers.”

While the new metadata specification does offer attractive improvements for VOD systems, it will create a more complex information base to manage. Armed with the new specification, it will be the job of on-demand systems, such as C-COR’s nAble software, to make sure that this more sophisticated metadata scheme doesn’t foul up on-demand services.

“Certainly when you add complexity, there is the opportunity to introduce more operational complexity,” Matarese said. In preparing for the Metadata 2.0 scheme, “the development in terms of our metadata management capabilities within our nAble product is largely done, except obviously the integration that needs to be accomplished with all of the folks that are distributing the content.”

One particularly tricky part will be funneling the new Metadata 2.0 systems to multiple interactive programming guides a cable operator may have fielded. For example, C-COR has deployments with Adelphia Communications Corp. and Charter Communications Inc. where some customers see a Digeo Inc. program guide and others see a guide supplied by Gemstar-TV Guide International Inc. The two guides may have differing ability to deal with added metadata information, Matarese said.

“We definitely have to make sure as we integrate systems so that those guide applications running on the set-top boxes at the end of the day present the title metadata,” he said. “We have to make sure that we send them information they can use and in a way that they can handle the information. If there is certain information in the metadata that they are not able to accept for whatever reason — or it doesn’t apply to them — we don’t end up pushing that information and cause confusion.”

Ultimately, it will be up to C-COR’s cable customers and content providers to decide when they want to upgrade their metadata systems. Matarese said most of those players will spend the next several months reviewing the new specification, and then start using it toward the end of the year or early in 2007.

“Flipping the switch — actually bringing content with the new metadata — as you can imagine there is a bit of a trick to that at times,” Matarese noted. “You have to make sure you are able to operate a system in a backwards compatibility mode for a certain period of time. That’s the sort of thing that has to be managed.”

Despite the potential issues, the expanding role of metadata shows that the cable on-demand systems are maturing and need more efficient technology underpinnings.

“VOD has been growing, and as it has been growing, metadata has been maturing. So this spec is showing the needs anticipated as VOD is evolving, and keep the metadata current with that,” Syed said.

HBO’s Zitter noted that going forward, it will govern a wider range of devices beyond the digital set-top.

“All types of equipment, which will only be expanding as consumer electronics people and cable people think about it, will need data to identify, for example, 'This is HBO and this is how I copy protect it,’ based on whatever the negotiated rules are,” he said.

“So whether television is linear, whether it is on-demand, whether it is going to a cell phone or whether it is going to cable, in the digital world metadata is as important as the picture or the sound,” said Zitter. “It tells the equipment what to do.”