Case Study: Multiplatform ITV Deployment

Case Study: Multiplatform ITV Deployment

Tim Halle, WGBH

One of the main problems in deploying an interactive television application is the wide variety of devices and the lack of shared standards between them. While this problem is widely discussed within the industry and steps are being taken to rectify it, as a practical matter it must be addressed for any deployment of ITV outside the laboratory.

One possible approach to this problem is to create code which adheres to a "lowest common denominator" of functionally across a number of platforms. Various attempts have been made at creating this kind of code, referred to in the industry as COPE (create once play everywhere), but this approach has unfortunately proven to be a practical impossibility. Accordingly, any real world deployment of ITV content across multiple platforms requires that a separate version of an ITV application must be generated for each platform.

An additional problem, one separate from the issue of non-standardization, is the issue of production time. Creating content for a daily or weekly television show over a wide range of platforms, each necessitating its own separate version of code, is a huge and expensive undertaking, beyond the reach of all but the largest production houses.

Our strategy for dealing with these issues was to repurpose existing web site assets, to reduce production time, and to create an open source ETV content publication system consisting of a database to house these assets and an application which drew assets from the data base and created a series of templated pages for each platform, to enable multi platform deployment. Details and source code for this applications is provided later in this document.

screenshot The production process

Antiques Roadshow is an excellent property for ITV. Each episode is divided into discreet segments, there is a mature web site to draw material from and an established "look and feel" to draw design elements from. Upon reviewing the show and the web site, we determined that we would create five different enhancements for each segment: Antique Speak, Tips of the Trade, an Appraise It Yourself game, Appraiser Biography, and a search function.

We then set work on the design of the pages in order to determine sizing and positioning of assets and text elements. Careful attention was paid to the traditional graphics issues associated with ITV, notably screen size (something of a non issue as this would be handled by the templates), text size (important in terms of both readability and how much text we could reasonably fit on a page) and color representation in the NTSC color space. More information on these subjects can be found here.

Once we had determined generally what the enhancements would be and how they would look, we reviewed the show and the website to determine more specifically what the content of the enhancements would be. Each segment was reviewed for repurposeable material from the web site for each category of enhancement.

In this process we discovered, and addressed, a number of issues. In some cases, while there was material on the web site pertaining to the object in a a particular segment, much of it was too long for use with in an ITV application and needed to be edited to an appropriate length. Other segments did not have any material on the web site pertaining to the object and these needed to be written. Finally some segments of the show are very short and do not allow adequate time for a viewer to review enhancements. It was decided that we would only "enhance" segments of two minutes or longer. This dropped the number of segments requiring enhancements from 23 to 15.

screenshot Once we had a firm grasp on what the specific enhancements would be, we then roughed out the needed database fields the enhancement assets. On this basis, we generated a spreadsheet which contained the needed fields. These included the time code of each segment, the necessary assets for each enhancement, a text transcript of each segment (for searching) and other miscellaneous information such as prices for the "Appraise it Yourself" game. Once necessary fields were defined, a database was created to house the assets. Asssets were then gatered and loaded into the database.

The open source ETV content publication system

Once we had the assets and design elements in place we began to work on our open source ETV content publication system. This system, implemented using Antiques Roadshow content, was designed to provide a framework suitable for content producers to create synchronized enhancements for video content without the need for substantial investment in ETV developer programs or training. There are four main components to this system:

1) The content database: As mentioned above, the database was populated with text and image assets to be used in the application. Images are associated with text which is then associated with timecode within a particular episode. This system was implemented using the open source MySQL database server, though almost any SQL-compliant system would work.
2) The core publishing system: This code, written in Perl, is the backbone of the system. It provides device-agnostic methods for accessing the content database, publishing HTML files, generating real-time search results, and outputting ATVEF trigger data.
3) Device-specific modules: For each ATVEF-capable device, code must be written to meet its specific needs (read: quirks). This includes both static HTML (such as the search form) as well as a Perl module to translate the output of the core publishing system into device-specific HTML. Our system includes modules to support Device Mosaic, WebTV, and AOLTV, plus an HTML 3.2 compliant default for unrecognized devices.
4) Device detection: There is also a central "browser-sniffing" HTML page (currently implemented using XSSI functionality of the open source Apache web server) to send devices to their appropriate set of HTML pages.

Source code and user information is provided here. This code is open source and freely avalible to all interested parties. However, while we encourage use and modification of this code, please note that this code is not supported.

While yet to be deployed, the resulting ARS application worked on all targeted platforms and was demonstrated in December of 2002 at the Broadband Plus show in Anahiem Caliornia.

Some additional thoughts

In this trial we supported Device Mosaic (specifically the version installed on the Sony TG-55 set top box), WebTV, and AOLTV, plus an HTML 3.2 compliant default for unrecognized devices. Furthermore this approach can be extended to non html based ITV systems thin client systems such as OpenTV and Wink. Finally this scheme can support devices besides interactive television receivers, for example wireless hand held devices such as PDAs and cell phones.

While time and funding were too short to fully develop it, using the same database we could create an application for wireless hand held devices such as PDAs or cel phones. This application, called "Antiquers Assistant", would allow searchable access of the archive of ARS material generated for the ITV platforms enabling users to look up information on a particular antique from a yard sale or antique store.

Another issue that was not fully explored was the possible role of asset management systems in a real world deployment of this application. Because we were only dealing with a single show for demonstration purposes, and were not involved in an actual production scenario, we did noty have to addess the realities of a production timeline. Clearly in a real world deployment it would be necessary to integrate the content generation with the overall website production process. Accordingly in such a scenario our tool would have to be modified to interface directly with whatever system was housing the web content.