Digital asset management (DAM) is a popular topic on the conference and seminar circuit. Why should it be of interest to broadcasters, and what benefits does it deliver? The proponents of DAM suggest it offers many advantages for the handling of media files throughout the processes of production and distribution.
DAM has been readily adopted by many corporate sectors for managing their document and image archives. The print and publishing community makes extensive use of DAM. The legal profession uses DAM for control of its large document stores. Photo and image libraries use DAM at the core of their online vending portals.
The broadcast sector has not taken to DAM with the same enthusiasm. What is different about the moving image? As existing users of the latest digital technologies throughout the production chain, broadcasters have much to gain from the implementation of DAM. This article looks at the challenges facing broadcasters who are looking to use DAM as part of the migration to file-based workflows.
The vendors of DAM systems offer a wide range of products. Their facility and feature sets run from basic to complex enterprise-scale systems. By definition, DAM manages digital assets. Lawyers speak of an asset as an item of property. Digital assets are a sub-set, property that exists in digital form. Generally, this means a computer file.
Electronic documents form one large and important group of assets. These are the conventional files of any business: word processor documents, spreadsheets, presentations, white papers, contracts, quotes and invoices.
Media businesses use a further group of files that includes images, Web content and audio-visual files. Other sectors also use image files — CAD files, seismic surveys — and these can be just as large as a video file.
Television broadcasters have traditionally maintained assets in the form of film or videotape. This physical media can be managed just like a book. Each reel is allocated a unique number and stored on shelves in a library. A card index or computer database maintains a set of records for the reels. There are tried and trusted practices for viewing and withdrawing tapes (or films) from the vault.
In 1998, when the joint SMPTE/EBU Task Force looked at harmonizing standards for program interchange, it introduced the idea of an asset being defined as content plus rights (to use). In the context of broadcasting, the management of digital assets also includes rights management.
The components of a DAM system depend somewhat upon the application, but there are common elements. Assets are ingested, along rights information. At the ingest stage, the asset is indexed and then cataloged. The files are held on a storage network, possibly a mix of disks and data tapes. Control information and metadata is held in a conventional database. (See Figure 1.)
Once the assets have been cataloged and stored, then provision is made to browse the content using the catalog and index. In many systems, access control provides security to ensure assets can be viewed only by those with relevant permission.
The final, and perhaps most important, stage is publishing. Here, the assets can be turned into revenue by distribution over numerous channels: broadcast, cable, print, the Web and cellular phones. For the broadcaster, publishing may include editing, finishing, packaging and, finally, transmission.
Broadcasters have been migrating to file-based workflows since the introduction of the nonlinear editor. Digital processing islands have emerged in post-production, in the newsroom and in master control. Elsewhere, programs and commercials are still moved around as tape or live video streams. (See Figure 2.)
A DAM system has to replicate the processes used for handling videotape: cataloging, ordered storage, indexes, and check-in and check-out procedures. In any library, it is essential that content can be found easily and with the minimum of information. A traditional card index stores a range of metadata: program title, producer, editor, dates for shooting or transmission, etc. The list is endless. Such data has been formalized in documents such as the SMPTE metadata dictionary for use with computer databases and DAM.
In the file-based world, this same metadata can be carried over from the card index. There are more sophisticated systems that automatically log material. They can analyze the video and segment it into shots tagged with time code. With speech-to-text conversion, it is possible to provide automated transcripts. These are typically used for continuous agency feeds in news operations. Within the closed world of program production, the team may have no need for such systems; it has the shooting notes and the scripts.
In the tape-based world, viewing copies are made to avoid damage to the master tape. These can be clones in the same tape format, or copies on VHS or DVD. DAM uses low-resolution proxies for viewing. This is not to avoid damage to the master, but to save network loading. An uncompressed HD file (1.5Gb/s) can be viewed using a streaming media codec at perhaps 300kb/s. This concept is not new to television. The offline NLE uses a highly compressed copy of the original media — a proxy — for the rough cut. The original uncompressed files are then used for the online conform.
Just as the NLE uses proxies, in common with DAM, they also make extensive use of small images grabbed from the video track (thumbnails) to represent each scene. The automatic logging systems perform a similar task of creating the thumbnails for the DAM.
The latest generation of camcorders is offering alternatives to tape, with recordable optical disks and solid-state flash memory cards. The disks can be captured by an NLE over Ethernet or IEEE1394. The memory cards plug into a regular PC card slot in a laptop editor, or they can use a card reader with a desktop workstation. Because the media files are wrapped in the MXF format, it becomes easier to offer cross-vendor compatibility. These camcorders create a low-resolution MPEG-4 proxy, and some create a thumbnail for each scene as they record.
The camcorders incorporate many of the functions of a conventional ingest station, enabling direct ingest from the camera to the DAM system. The advantage to the broadcaster is twofold: lower costs, plus faster than real time ingest rates. For news operations, these are a real bonus.
Over the last 10 years, since the inception of reliable video servers, television channel playout has changed from tape to using files. The first change was to spots and interstitials. As disk capacity increased and the price dropped, it became viable to play long-form programs from disk. A number of DAM systems have evolved for this specialist application and meet network demands for 99.9999 percent reliability. A missed spot is lost revenue.
There are many reasons that broadcasters are wary of DAM. First, there is the old saying, “If it's not broken, don't fix it.” Workflows have evolved over many decades that deliver programs. In an arena of rapidly changing technology, that saying cannot hold. Other more specific reasons include lack of buy-in from the financial officer, a perceived lack of metadata standards and an unproven price or cost benefit.
The first two are partly an issue of education. DAM systems are complex. They are a blend of IT and media technologies, often including sophisticated cataloging engines. Major changes may have to be made to working practices before real cost benefits are realized. There is risk attached to these major changes, and that risk has to be balanced against the possible benefits.
If DAM is trusted to handle the revenue generation in playout, then why not roll it out across other areas of program creation and publishing?
Benefits of DAM
The business of television is in the middle of a step change in technology. Files are replacing tapes. Digital delivery includes IPTV, DVD, Web streaming and third-generation cell-phones. Real-time delivery via the STL to a tower is no longer the sole delivery channel for content. DAM has been designed from the ground up for this new environment.
The developments in delivery channels are creating demand for content that has been repurposed to suit the demands of the channel. For content publishers, a repurposing cycle is replacing the traditional linear workflow of television production. The globalization of the media providers adds the administrative complexity of managing multiple language soundtracks, subtitles and closed captions. (See Figure 3.)
The consolidation of call-letter stations into groups has led to a centralization of creative and technical resources. At group headquarters, finished media radiates to the local stations. The local stations are often solely an injection point for local news. Fiber networks act as spokes to deliver content as files. DAM can efficiently manage this server-to-server file exchange. The local stations can browse low-resolution proxies of media stored at group headquarters. Metadata exposes useful information about programs, commercials, interstitials and PSAs. To provide this same service in a tape-based world, we would need a full-time dubbing provision, plus the cost and delays of couriers.
With DAM, the media repository can be made available at the desktop to anyone within the group, even when separated by hundreds of miles.
Perhaps the biggest impediment to the adoption of DAM is fear of the new. Meanwhile, file-based workflows are being rapidly adopted. DAM delivers sensible management of the ephemeral media file. The familiar tape cassette is headed for the sole task of being a capture and archive medium.
David Austerberry is the editor of Broadcast Engineering's world edition, as well as a technical writer and consultant on video technologies. He is author of “Digital Asset Management: How to Realize the Value of Video and Image Libraries,” published by Focal Press.