Media-aware storage
Jan 1, 2009 12:00 PM, By Joey Faust
New video storage systems offer unique advantages.
There are challenges here, such as buffer management or dealing with GOP structures, but the benefit of storage that actively manages, assembles and disassembles clips for delivery to an application is undeniable. For example, this storage could be used to package an EDL automatically, below the application layer.
This type of system would be especially useful in facilities that have spent years perfecting a tape-based workflow and depend on the linear nature of tapes and certain video servers to prepare their media. This would also allow a facility to capture portions of a single asset over several sessions, or allow an editor to save just the changed portion of an asset.
Automatic cataloging
A storage system can also have an assumption of what metadata is useful to catalog. This would allow the metadata that can be automatically generated to collect at the storage layer instead of at the application or media asset management (MAM) layer. Media-aware storage could automatically catalog duration, format, source, frame rate, resolution, color depth or any data that live in the essence wrapper.
Storing this data in the file system provides faster recall than a database-style MAM system, which would store data in a separate file that must be kept consistent with the file system. Databases have become more efficient in the past 30 years, but cataloging asset metadata with the storage system can simplify the design of media management applications and prevent the need for a separate database.
Video processing components can be used at the storage layer to gather more metadata automatically, and other wrappers or VANC data can be leveraged as well. Rights data that is associated with the media asset could automatically inform the access control of the storage system by mapping the rights in the media asset to the users/groups of the system.
Proxy workflow
The concept of a proxy workflow already is well-understood in the media industry. By expanding the concept to include more than simply a low-resolution and a full-resolution version, the concept becomes less about saving bandwidth and processor power and more about providing the right version of the asset to the right user or application. Business rules at the storage level could be used to present different-sized assets to different applications.
By combining a storage system that manages proxies with a rich security infrastructure, a facility would be able to prevent unauthorized users/applications from accessing or even knowing about other available resolutions or formats of an asset.
Format independence
The ultimate goal is this: Different applications requesting the same media asset get different versions of that asset, depending on the resolution and format that the application is expecting, and the storage system is responsible for generating and managing that versioning.
Format independence like this is especially useful for the exploding world of new media distribution. Contemporary production houses must generate tens or hundreds of differently formatted media assets as they hypersyndicate their content. Distribution requires not only SD and HD versions of TV material, but also streaming and electronic sell-through versions for online distribution. If the storage system knows how these assets are derived from one another, it can present the appropriate format to the appropriate distribution channel with minimal involvement from production staff.
Service-oriented storage
As the concepts of media-aware storage are explored, a trend begins to emerge: The best way to service the complex storage needs of media facilities is to combine streamlined IT storage with value-added media services. “Services” in this context could describe an actor in a service-oriented architecture (SOA), wherein every component of the system has a purpose at the business level and acts independently of the other components. Transcoding to provide format independence, for example, is a service to the storage system, because it adds value to the media workflow and provides a basic, business-oriented building block for media facilities.
A key aspect to SOA is the technology-independent interoperability of services. A higher-level storage service composed of multiple infrastructure services providing capabilities such as basic metadata logging, media movement and transcoding should, according to the precepts of SOA, expose all of these interfaces programmatically to external systems in addition to leveraging them internally. Based on this exploration of media-aware storage, the services that could fall under the storage “umbrella” are as follows:
- archive;
- media movement;
- cataloging;
- transcoding and format conversion;
- metadata management;
- rights and clearances;
- versioning; and
- editorial (to a limited extent — mainly the storage and processing of EDLs).
This group of functionality could be termed the “media service.”
Future of media-aware storage
Moving forward, some of these models will, no doubt, have greater “sticking power” than others. In 10 or even five years, the status of media-aware storage in the industry will look very different than it does today. It is almost guaranteed that some of the technology trends surfacing this year will be out of vogue by that time, while others will be around and integrated into the industry's storage concept in a much more permanent way.
The concept of a media service is becoming increasingly necessary in a world where complex, file-based facilities are being constructed in less time for less cost. There is a strong need here, however, for standardization. Initially, every vendor will have its own definition of service-oriented storage, so the various solutions in this space will in no way be comparable.
The media equation is a complex one, so the generally-accepted IT principles about storage (including recent trends toward service orientation) do not necessarily mesh with the needs of the media world. Therefore, the best solution for the industry is a vertically-integrated one (a media service) that can, itself, interact in the horizontally-integrated world of the modern media facility.
Joey Faust is a consultant with National Teleconsultants and co-author of the 2008 book “The Service-Oriented Media Enterprise.” Faust presented a longer version of this article at the 2008 SMPTE convention. A copy of that version is available from www.smpte.org.
| Want to use this article? Click here for options! |  |
