DVD provides a broad range of capabilities for delivering a great viewing experience with high-quality video and surround-sound audio. Yet authoring the interactive interface for DVDs is heavily constrained by the capabilities of low-cost set-top players that were targeted when the standard originally was developed. Even worse, these constraints resulted in a rather idiosyncratic authoring design, with limited programmability, a bunch of special-purpose registers, restricted modes and states, and severely limited graphics overlays.

As a result, even today's professional tools hide much of the interesting potential of the DVD specification under kinder and gentler "abstraction" layers that package up commonly used functions. And while the highest-end tools do expose all of the gory detail of the raw spec, they then require laborious manual work to code up and set all of the required operations and modes. Even worse, none of this hard-earned knowledge for DVD design then transfers to (or from) other types of multimedia authoring.

Enter the next generation of DVD: high-definition blue-laser discs that raise the bar on the playback experience with beautiful HD video. It's not just the pretty picture; this new generation of DVDs also promises a significantly more powerful platform for authoring interactive presentations, including general programmability and built-in communications with other devices and the Internet. After all, if even today's cell phones can communicate over multiple channels, play 3D games, and stream video and audio, it's reasonable to expect a next-gen DVD player to provide much more sophisticated multimedia experiences, such as those we have come to expect from Web applications.

One note before we proceed. This story will focus on authoring on Blu-ray discs, which of course support HD. The competing format that aims to put HD on a DVD is called--either confusingly or conveniently, depending on your position--simply HD DVD. In this story, I'll refer to both formats as being capable of putting "HD on DVD," but don't confuse it with the specific format.

Figure 1 - Here's an example of what the next generation of Blu-ray disc authoring will look like to users. This is the first-level interface, known as the Video layer. All of the images are frames from motion video (note the motion in the clip on the right), and the background graphics also are animated as separate layers.

We're looking at Blu-ray in this story because the Blu-ray Disc Association was willing to speak publicly about the next wave of authoring. Based on my discussions with HD DVD representatives, we can expect the general capabilities of HD DVD authoring to be similar. For more information on Blu-ray versus HD DVD, see the "HD on DVD Formats" sidebar.

Even though the formal specifications for the new HD on DVD formats are currently being developed, enough information is available from public demonstrations of design concepts and discussions with the sponsors to provide this preview of how to start thinking about next-generation authoring.

For today's midrange developers-corporate DVD, for example--the good news is that it's quite reasonable to imagine that today's "abstraction" layer tools could be adapted to support authoring of at least the straightforward HD DVDs that have much the same workflow and interactivity as today's discs.

For more advanced productions, authoring will require a new set of skills based on programming, and draw more on expertise from developing interactive Web applications and more traditional multimedia authoring tools.

The examples of next-generation interactive DVD interfaces shown are provided by the Blu-ray Disc Association (www.blu-raydisc.com), and were captured as screen shots from recent conference demonstrations. These were developed as examples of possible scenarios in order to solicit feedback and discussion; the actual interactivity specification for Blu-ray was due to be completed by the end of 2004.

The application format for HD DVD is under a similar discussion by the DVD Forum, although no specific information is yet available on HD DVD authoring. Junko Furuta of the Toshiba International Media Relations Group was able to provide some perspective, saying that they also anticipate some kind of programming capability and are considering interactivity, including Web connectivity. They expect that new tools will be required for HD DVD authoring; however, "We will fully utilize current authoring tool assets to minimize additional investment."

Figure 2 - The next wave of DVD authoring will allow for much more interactive scene selection, which doesn't require users to step in and out of pages of static images that contain only about six scenes. The interaction can be fully programmable. In this example, scenes are chosen by scrolling through the dynamic list between the two arrows.

One decision already made for Blu-ray authoring is that it is being designed in two layers: a base Video layer much like existing DVDs, and an Interactive layer using Java and including Internet connectivity.

The Video layer provides constructs similar to today's DVDs--video, menus, and navigation--but without the irritating modal constraints and frustrating limitations. The Video layer also has more motion and interactivity built in. The intent is for this layer to be authored with software much like today's authoring tools, in a similar way to what Sonic has done in adapting its DVD Producer tool to support authoring HD Windows Media Video DVDs (www.sonic.com/products/dvdproducer; see the December 2004 issue of DV). "One key objective for the BD [i.e., Blu-ray Disc] group is to keep the authoring environment as close to DVD as possible," says Andy Parsons, senior vice president of product development and technical support at Pioneer Electronics, "so that the process can follow a similar path, although obviously with more sophisticated features."

The Interactive layer is based on a Java programming environment and includes a communications interface that accesses external devices and the Internet. Unlike with current DVD, the interactive layer can run in parallel with video playback, permitting not only menus to display along with playing video, but also full interactive applications.

The basic Video layer for Blu-ray is intended to provide full-color HD interactive menus that combine motion video, animated background elements, and dynamic text overlays. In Figure 1, the yellow background behind the menu buttons is animated with multiple graphics layers, and the video thumbnails below play continuously. The interface is still designed for interaction with a remote control instead of a keyboard, but now it's much more responsive: the buttons animate and can have click sounds.

Even this base Video layer escapes the frustrating constraints of current DVD authoring. First, it removes the arbitrary distinction between menu and video display modes, so you can display menus with full video (not just brief repeating clips) and display pop-up menus over video (e.g., to conveniently enable a director's commentary without interrupting video playback). In addition, the base Video layer eliminates the severely limited color palette of DVD's current single subpicture overlay layer, which is used for both menu button highlights and video subtitles. Instead, it permits arbitrary text and graphics to be composed with video-think Web-like or Flash-like interaction, with arbitrary highlighting effects and even built-in page transitions.

Existing authoring tools could be redesigned to target this new Video layer, providing an interface similar to today's discs while also removing at least some of the DVD constraints. Workflow could also be simplified because menus are composited more dynamically, instead of needing to be flattened into a single pregenerated video sequence.

The additional Interactive layer provides the full flexibility of programming in Java, so even tasks like scene selection can become more responsive and convenient. Today's DVDs typically lay out scene thumbnails over a linked set of sequential menus that covers several separate screens because only six or so images will comfortably fit on a single screen.

To access a specific screen, the user has to navigate through two interfaces on the same menu design, first moving through the group of menus to get on the correct menu and then selecting the desired thumbnail. This also has the unfortunate effect of cutting off and then restarting the background audio when linking from one menu to the next.

In this example with a Java-based interface, the scene selection menu can simply scroll through all of the scene thumbnails on the same menu (Figure 2). Motion video and audio can play continuously instead of just short loops, and the menu can display more detail for the current selection. The audio itself can be layered with a background track, plus audio from the selected scene, plus sounds on user actions.

Figure 3 - Expect DVDs to be Internet connected. Here's an example of a disc simultaneously accessing info both from the local disc and over the Internet. Note the up-to-the-minute info available in "studio news," as well as downloadable games.

Of course, as with Web interfaces, access to Java programming means the interactive experience can break the bounds of menu presentation and instead be used for games or other interactive applications. This again eliminates the frustrating constraints of current DVDs: The arbitrary distinction of DVD-Video versus DVD-ROM content is gone, along with the need to implement different interfaces and experiences for viewing on the televisions versus PCs. The full interactive, connected PC experience will now be available on a broadband-connected DVD device.

This integration of video playback and interaction in the same interface also permits merging the two layers. The Java layer is fully programmable, so it doesn't have to be playing DVD content at all, or viewers can have multiple simultaneous experiences like playing a game while a movie continues in the background. In the latter scenario, the remote control serves as the input device and scores can be stored in persistent memory on the device. Beyond the local device, DVD applications will also be able to link out to the Web for dynamic content or even for multiperson games and activities.

Beyond programmability, the Interactive layer provides connectivity over the Internet, and over a local network to computers and other consumer electronic devices. Through this connection, studios can make additional content available to consumers, including clips, games, new releases, and even enhanced subtitles.

In Figure 3, the menu has been dynamically updated to include both the content available on the local disc, plus up-to-the-minute information available over the Internet such as news, trailers, Java games, or an online store.

Figure 4 - Future DVDs will certainly make use of Internet access to allow viewers to shop at online stores. Here's an example of a user going online to purchase tickets to a movie sequel.

This connectivity offers the potential to more tightly integrate the movie studios with the playback of their own films, so they can offer bonus information and merchandising associated with the DVD as it is played. For example, a pop-up menu might offer featured products for purchase. Similarly, the publisher could offer up-to-the-minute discounts on related products such as movies currently showing in theaters or concert tours (Figure 4).

Figure 5 demonstrates how connectivity capabilities can further extend the potential of a disc-based product, blurring the current line between the set-top DVD playback experience and PC-based access to DVD-ROM materials. Instead of requiring the user to go to a PC to search the disc's directories or run a special application to access computer-readable materials, the set-top device can open up a network connection and transfer the files directly from the player to the PC.

In addition, today's DVDs require jumping off to a new full-screen menu to present each set of options, which can be disconcerting and confusing as the viewers lose their context in the navigational flow (unlike Web sites that usually display the nested hierarchy). Instead, next-gen DVD players can present these options in a pop-up menu that floats above the main disc menu.

Figure 5 also suggests that digital rights management information can be controlled from the disc and player. This will be an interesting issue that must be addressed for next-generation DVD, especially when discs can run arbitrary programs that can download and upload any data stream, including other media files and applications (or viruses).

These "conceptual demonstrations" of DVD authoring concepts from the Blu-ray Disc Association provide a helpful preview of the direction that next-generation high-def DVDs are heading. High-def DVD will clearly offer a much broader canvas for developers, with more options and flexibility through enhanced interactivity and communications. We should see more details by the end of 2004 with the release of the Blu-ray interactivity specification, and both camps promise products on the market later in 2005.

But what does this future mean for DVD authors, and for authoring tool developers? It's clear that moving to a much more flexible and programmable interface will require significant adjustments for current DVD authors, who are used to laying out menus and links manually and optimizing the use of subpicture colors. There also will be new opportunities for Web and desktop multimedia developers to move into DVD production.

As with all new systems, this change also will require the development of a new generation of authoring tools. The Blu-ray Disc Association reports that initial tools are being developed internally by its members, and by other authoring tool manufacturers (for example, Sonic has joined the BDA).

Figure 5 - Internet connectivity will mean much more than a disc grabbing current data off the Web. It will also mean that downloads of large media files will be possible. Here is an example of copying footage from the DVD player to a PC over the local network. As set-top DVD players get smarter and more connected, they become more prone to hacking and viruses, however.

It's reasonable to expect that the first tools could be adapted from existing midrange DVD authoring products that simplify and package the DVD specification under an "abstraction" layer. With some modifications, the same interface could be used to create basic HD productions similar to current DVDs (i.e., targeting the BD Video layer). This provides a quick path to take advantage of the larger capacity and distribute HD content, especially for corporate users and early adopters.

However, more interactive productions will require Java programming skills more along the lines of Web application development. This probably also means a new industry of authoring tools and components developing for HD on DVD. DVD authors then could program to common user interface and communications libraries (e.g., for pop-up menus or network transfer) or have the flexibility to roll their own custom interface. Or multimedia tools like Flash might be targeted to the high-def DVD interface.

This move to programmability will clearly be a dramatic change, as today's passive DVD viewer transforms into an active user, and today's DVD authors will need to think more like software developers. Time to brush up on your Java programming skills and to keep an eye on what's happening with tools like Macromedia Flash and Director.

Blu-ray Disc Association (BDA)
www.blu-raydisc.com

DVD Forum (HD DVD)
www.dvdforum.com

Sonic Solutions - DVD Producer
www.sonic.com/products/dvdproducer

As seems to be the rule for DVD formats, there are again competing formats for the next generation of HD discs: Blu-ray Disc (BD), driven by Sony and an alliance of major companies (www.blu-raydisc.com), and HD DVD, developed by Toshiba and NEC and endorsed by the DVD Forum (www.dvdforum.com).

The fundamental differ-ence driving these different designs is storage capacity. HD DVD is a more incremental improvement that supports a 15 GB single-layer or a 30 GB dual-layer disc, while Blu-ray is a more aggressive design that supports 25 GB for single- and 50 GB for dual-layer discs (with different capacities for recordable formats).

HD DVD supporters argue that its more conservative design will make the product easier to manufacture and enhance backward compatibility, and that the capacity is sufficient for its intended use for delivering HD movies on DVD. But more bytes (and especially more gigabytes) are always welcome for other applications, such as HD video recorders or computer storage. On the PC side, "You really can't have too much capacity," says Brian Zuker, technology strategist with Dell (a Blu-ray supporter). He points out that today's higher-end desktops ship with 400 GB hard disks, so that just as the CD replaced the floppy diskette years ago for storage and archiving, advances in mass storage require significantly larger optical media capacity.

For the HD content, both formats have adopted the same basic video formats (MPEG-2, MPEG-4, and Windows Media), and similar audio formats, including variants of Dolby Digital. The manufacturers expect the first HD on DVD consumer electronics products to support recording as well as playback, avoiding the current distinction between DVD players and recorders by providing a single VCR-like solution for both recording HDTV and playing prerecorded HD content.

Dell is targeting early 2006 for the availability of PC Blu-ray drives, and expects rapid growth (and associated price reductions) due to the pent-up demand across the markets, from HD recording to PC archiving.

The other major issue that must be resolved before these products can be marketed is providing strong enough content protection to satisfy broadcasters and studios.

In the battle for supporters, Sony took an early lead with Blu-ray because it owns Columbia Pictures and is acquiring MGM. As we were going to press, HD DVD announced the support of several major studios: Paramount, Universal Studios, Warner Bros., and New Line Cinema, but this support wasn't necessarily exclusive.

Stand by for a full-up format war--the details of the video content and even the interactivity may well be very similar, but the physical discs are not.