Metadata is information about the content that users are interested in using. This content of interest can be referred to as the essence. The essence can be a small bit of audio or video, raw audio tracks, B roll or an entire program, a stereo mix or a 5.1 surround mix, an immersive audio mix, a single news piece or a newscast, a promo or a commercial ' anything that users are interested in using, saving, and finding again.

Metadata is useful if a user wants to send or broadcast the essence, and wants the receiver to gain information about the essence. Metadata may contain the author, shooter, date of creation, owner, an edit decision list for video or audio or both, technical details about the essence, where the essence has been used before, who to pay for its use, how to use the available audio channels, how to adjust audio playback level, and more.

Metadata is extremely valuable but, so far, it is most useful in closed systems. Metadata has, unfortunately, been difficult to maintain and manage since the beginning and thus has not been used to maximum advantage. It has, in fact, been quite one-dimensional. Metadata exchange has only been possible within a limited number of systems, where it is used to share a limited number of very specific bits of information.

In a closed system, there is some assurance that the essence and metadata will not be separated. Examples of this are playout systems that ingest content, associate metadata with the essence, store the essence and metadata, schedule playout, and archive the content. However, if ingest, scheduling, playout, and archiving are handled by systems from different manufacturers, the essence and metadata can become separated or the metadata may simply be discarded in one of the stages of the workflow.

The current ATSC broadcast system, used in North America and in some other countries around the world, reliably delivers Dolby metadata from transmission chain to consumer - in a single step. Although metadata is widely and successfully used for premium services, it has proven to be nearly impossible to assure metadata continuity from program creators to distributors to over-the-air broadcasters.

Any break in the metadata chain results in unpredictable results for the broadcast consumer; so values are kept static and the audio is, hopefully, adjusted to match.

This situation cannot continue. New possibilities for content delivery will include audio-level information, immersive audio, also called 3D and already in use in cinemas, home theater, games and music, personalized audio, and information for user interaction and commerce with broadcast and over-the-top (OTT) TV content.

The number of devices that viewers will use to consume TV content is growing and includes a variety of handheld, mobile, small, large, and very large screens, mono, stereo, in-ear, over-ear, small speaker, and multi-channel surround sound devices. It will be impossible to provide consumers with a great experience on all of these devices without reliably delivering metadata along with the content.

Metadata will provide new opportunities for broadcasters to create revenue streams while encouraging viewers to participate in broadcasts instead of simply watching them. Metadata will no longer be convenient; it will be indispensable, reliable, and necessary, to maximize both the monetization and the enjoyment of content.

The time for working around metadata is over. The time to embrace it is here and, thankfully, so are new methods and tools for delivering it.

The author Ken Tankel is a Platform Manager-Television at Linear Acoustic based in Lancaster, Pennsylvania, USA.