In today's world of digital media, metadata are inescapable. Metadata are pieces of information about other information — they are data about data. In a broadcast sense, they are descriptive information about program elements. In a tapeless world, metadata act as digital labels.
Content-management solutions are available from several vendors. Shown above is Virage’s VS Archive. Photo courtesy Virage.
Media-industry terminology generally describes content as consisting of essence (video, audio, data) plus metadata (descriptive information about the essence). An asset is thought of as content and its associated rights (who owns and controls the content). But, in this article, the scope of the term metadata includes rights-management information.
Broadly speaking, an asset's metadata comprise three distinct types of information: descriptions of the essence, technical parameters and rights obligations. Metadata provide the content descriptors used in media-asset-management (MAM) systems and, collectively, they enable indexed content storage and retrieval.
Metadata lifecycle
Figure 1 illustrates metadata's role in the production and distribution of programming for broadcast. The four phases in the lifecycle of metadata are (essence) creation, (program) assembly, (asset) distribution and (library) archiving. For each phase, the illustration lists associated open-standard metadata formats and offers representative examples of metadata attributes.
Figure 1. The four phases in the lifecycle of metadata are (essence) creation, (program) assembly, (asset) distribution and (library) archiving. For each phase, the illustration lists associated open-standard metadata formats and offers representative examples of metadata attributes. Click here to see an enlarged diagram.
Various metadata standards are best suited to a particular phase in the production and distribution processes. Some are open standards, intended to be freely available and compatible with each other. Others are proprietary, used by groups of OEMs and offering a turnkey solution to MAM. But no one standard covers all phases of the metadata lifecycle.
Creation
When creating graphics elements or ingesting programs, it is important to generate metadata that enables efficient authoring functions. Appropriate descriptive information such as time, date, location, talent, director, producer, etc. must be logged and associated with the newly created essence. Technical details pertinent to format conversion, color correction, equipment calibration, compression encoding, EDLs, transitions and steps taken in the editing process are all metadata that must be recorded for editing and assembly. Rights must be associated with particular elements so that individual contributors can receive production credits and royalty payments.
Assembly
The assembly phase brings together all the elements (video, audio and logo) into a program and makes them ready for distribution. From this point on, there is little use for much of the metadata pertinent to editing the original source material into a program element. Technical data necessary for decoding at the consumer's receiver/decoder will be placed into the program stream. Creators' contributions and copyright information must be catalogued in this stage and distribution-rights management (DRM) must be activated before publication and ultimate loss of control.
Distribution
It's in a master control room (MCR) that the program, commercials, logos and other elements go to air as scheduled on the playlist. Each of the three primary types of metadata are now contained in a single program stream. Technical information is conveyed in the MPEG video or AC3 audio packets. Program descriptions are communicated by PSIP. Redistribution-rights management is accomplished through the broadcast flag. All these packetized elementary streams are combined into a single transport stream. Transmission of the completed program can be through terrestrial, cable or satellite.
Individual program elements can easily be repurposed. For example, an audio clip can be used by radio or streamed on the Web. Individual video frames can be released in print. Clips or completed programs can be repurposed as streaming video over the Web. Video-on-demand services can offer previously aired programs over cable as pay-per-view service. These collateral distribution channels can provide added revenue to the program's creators.
Archiving
The networked homes (and world) of the future demand instant access to, and retrieval of, any desired media item. Recommender systems that sift through available media metadata to find just the kind of asset you personally like and alert you to its availability are necessary to maximize your use and enjoyment of the abundant media choices. There are efforts underway to expand today's libraries to media libraries, which the media industry should support. The National Digital Information Infrastructure and Preservation Program (NDIIPP) is an effort by the Library of Congress to build a national infrastructure for the collection and long-term preservation of digital content. Appropriate metadata, attached at various times during asset creation and distribution, should be compatible with this public archiving effort. Television broadcasts, after all, have historical value.
Workflow enhancements
The intelligent implementation of metadata in a MAM system, along with improvements in a digital infrastructure, can increase workflow efficiency and offer other benefits such as:
- Instantly accessible content — everyone can access it as it is ingested.
- Streamlined asset retrieval — intelligent metadata facilitates searches and saves time. You don't have to physically track down content.
- Facilitated re-editing — the original edit decisions are stored in metadata and source material can be easily traced and retrieved.
- Facilitated file transfer — not having to reformat files saves a time-consuming step.
- Simplified rights management — DRM embedded in an asset can simplify content rights clearance and payment, save time and ensure full control over an asset's use.
- Simplified office functions — integration with back-office functions and event scheduling eliminates manual logging of content, avoids clerical errors and automates billing and royalty payments.
Issues
The following paragraphs address some issues associated with implementing metadata in the workflow-enhancement process.
Element creation
Capturing metadata properly can be a significant task. The key is to automate the metadata process as much as possible, beginning at the point of creation. Start by carefully analyzing workflow and metadata requirements. Remember to transfer those processes across all departments to help prevent problems with asset management. It is extremely important to understand how the metadata will be used and propagated through the creation and distribution process.
Attribute naming conventions
You must establish properties, attributes and naming conventions as mandatory standards throughout a facility. For instance, is a tag “home run,” “homer” or “HR”? Your MAM search engine will need to know that each of these terms has the same meaning. Be consistent in your use of case, a “Home Run” may not be a “home run” across all platforms. Do not use illegal characters such as / or @. Whatever convention you decide upon must be applied and enforced enterprisewide or your assets will be unsearchable and virtually lost.
Flattening
As elements are created and assembled, and the finished program is distributed, it is important to include some, but not all, of the metadata pertinent to each phase. This parsing of the metadata is known as flattening. For example, the editing information used during element creation is of no use to a viewer and can be discarded. Conversely, copyright information is metadata that will have important uses after the program has left the control of the originator and should be persistent. So, while it's always possible to remove metadata, be sure you don't take out information that will be needed later.
Platform and file interoperability
Open standards vs. proprietary implementations are conflicting approaches to metadata standardization. Using different standards can result in an inherent lack of compatibility and cause difficulties when trying to create content with one vendor's application and then working on it with a different vendor's application. Even when different vendors implement the same metadata standard, problems with file compatibility still can occur. If you believe that multiple vendors may be involved in your solution, require them to demonstrate file transfer early.
Digital rights management
At the heart of the matter is revenue generation, and the key to this is rights administration and enforcement. Rights management of program elements during program creation and rights management of a completed program after dissemination to the consumer are two separate issues. Prior to distribution, copyright is the responsibility of the program originator. Tracking the rights of creative contributors is a legal responsibility. The recently mandated FCC broadcast flag is intended to stop unauthorized copying and distribution of programming once it reaches the consumer. There is an added benefit when repurposing content to other platforms. Copyright metadata must be persistent through all phases of creation, assembly, distribution and archiving.
A tower of metadata babel
Broadcasters can choose from numerous emerging metadata standards. But the interoperability of the available standards is in a developmental stage and has not been standardized. The goal for broadcasters is to coordinate metadata relevance through all phases of program creation, distribution and archiving. This will afford them the opportunity to realize new revenue streams through repurposing content.
For more information about ongoing metadata standardization efforts, visit the following Web sites: www.smpte.org, www.aes.org, www.iso.org, www.ebu.ch, www.pro-mpeg.org, www.atsc.org, www.digitalpreservation.gov, andwww.aafassociation.org.
Note: The reflections from Philip J. Cianci in this article represent his own opinions. Photos provided by vendors not necessarily associated with ESPN.
Philip J. Cianci is broadcast media engineer at ESPN.
