Effective DAM system
May 1, 2007 12:00 PM, BY DAVID AUSTERBERRY
Workflow management and optimization are keys to creating effi cient broadcast processes.
Storage
The ingest room at Turner Broadcasting in London uses a TMD workstation to manage acquisition of videotape.
Unlike document management, the design of video storage systems is complex. At a reasonable cost, the system should be able to serve large files at high data rates. Systems over 50TB may well need special high-performance file systems, as office systems like NTFS and CIFS may not meet the requirements. A typical system may have four hierarchical layers: SCSI or Fibre Channel drives for editing full-resolution video, SATA or Serial Attached SCSI (SAS) for lower cost nearline spinning disks, an automated tape library for Super Advanced Intelligent Tape (SAIT) or LTO data tapes, and a low-cost deep archive of tapes on shelves.
These storage layers all need management that ensures what is needed is served in a timely manner. Conventional hierarchical storage management (HSM) is rarely suited to applications like playout, where large files may need to be recalled from tape rapidly. The HSM needs to be aware of the playlist to prioritize restoration to disk, which is a key function for a product developed especially for the broadcast industry, rather than for enterprise IT.
Publishing
Early DAM had simple publishing requirements, usually involving running out a file to Digital Betacam. Multiple delivery channels have made publishing more complex. A file may be needed as 1080i or 720p in MPEG-4 AVC, SD in MPEG-2 or 320 × 240 in a mobile codec. There have always been different frame rate requirements for 25fps and 30fps, with 24fps a new alternative.
It has become mandatory for DAM to include either an integral or third-party transcoding engine through Web services. Such engines also need control from the workflow to schedule jobs.
Infrastructure
Aside for the core functions, DAM will also include security and interfaces to messaging systems. Security provides a layer to control access to content, to authenticate users, and to group and assign roles to those users. A given role may be allowed a subset of functionality and limits to write access. Access can also be managed on a project basis.
Extra features
The essential extra features include NLE integration, links to program and artists' rights management, resource scheduling (human and hardware), transcoding and workflow automation. If DAM is used alongside playout, then links will be required to program, planning, traffic, sales and playout automation.
Once implemented, DAM is a great enabler. Review and approval requires little more than a Web portal. Program sales can be enhanced by exposing the archive to potential customers, and repurposing channels, such as for IPTV, becomes far more cost-effective.
It's not just audio and video
DAM has always stored metadata to aid searching and the production processes. Television production can carry large amounts of textual data from production notes through to scripts. As a product enters the post phase, it acquires graphics, such as Photoshop, animation and 3-D files. The asset management system must be able to handle all the common formats used in broadcast, which is not a short list.
Transcoding
Early systems encoded content at ingest as proxy at a low bite rate for browsing and an offline resolution for cuts-only editing. The content was simultaneously encoded at broadcast resolution as the primary digital asset.
As broadcasters optimize their systems, they want I-frame coding to support editing and long-GOP for long-term storage to make efficient use of their archives. Transcoding can also be used in content publishing applications as broadcasters deliver to a wider variety of devices like iPods and mobile TV receivers. This has led to a demand for transcoding engines as well as encoders. This part of the system design should be considered carefully to avoid the artifacts associated with concatenation when performing several transcodes.
Media assets
Few productions are entirely file-based. Film, videotapes, audiotapes and optical disks may all be used in the production process. These physical assets need to be integrated into a DAM system so they can be searched and retrieved in the same way as online digital assets. Traditional library software with bar codes provides the functionality, so a link via Web service should provide easy integration. Proxy viewing, however, assumes that the physical content has previously been digitized and indexed.
It's important to note that the distinction between media asset management (MAM) and DAM is blurred. Many products offer considerable overlap or even total support of physical and digital assets.
Implementation and change management
The most important question to ask when selecting asset management is, “Will it be the right system for my business?” It is not unheard of for businesses to be on their third vendor after products fail to live up to promises. Such issues can be avoided by running pilots, as the best way to become familiar with a system is to use it in earnest.
DAM touches all parts of a business. Therefore, selecting the right product is essential to the efficient operation of the business. A wrong decision will affect the bottom line and alienate staff.
There are four principle costs when deploying DAM:
- the product cost;
- the fees for the professional services to implement the DAM;
- the ongoing maintenance costs; and
- the staff time needed to implement the inevitable workflow changes when switching to file-based production.
The fourth cost is most difficult to measure. It is essential to employ proper change management to avoid unexpected costs. Change management should ensure the proper acceptance of DAM with attendant operational efficiencies that should lead to cost savings.
Digital asset management has progressed in the last few years to become a fully featured infrastructure for file-based production and broadcasting. Early products were little more than a fancy file manager. The current round of products has evolved to meet the real needs of broadcasters by adding to the basic toolbox. The integration of workflow management and control of video storage, alongside the release of more cost-effective products, means that asset management has become essential for broadcasters who want to lower costs, yet deliver more.
Summary
As more broadcasters use DAM, product costs will drop. This can only accelerate its acceptance.
The second edition of David Austerberry's book “Digital Asset Management”can be ordered directly from the publisher at www.focalpress.com. The book is available from several booksellers.
| Want to use this article? Click here for options! |  |
