Tips on DVD Authoring and DVD Duplication
DVD Authoring - Introduction The postproduction business has certainly come a long way in the past decade or so. This includes the duplication/authoring aspect of post, as home theater systems are becoming more common and high-definition (HD) television sales continue to rise. In fact, a new generation is growing up with a completely different perspective on home entertainment. Instead of simply viewing films in their homes in the same way they were shown in movie theaters, people can now quickly jump to specific scenes, watch behind-the-scenes interviews and deleted scenes, and even play games. That s all created by DVD authoring and digital technology. DVD authoring is the process of collecting audio, video, menus, subtitles, and photographs and putting those pieces into an interactive branching structure that eventually becomes a playable DVD. It s much more than just burning a DVD of various files. Since there are multiple items, creating an interactive DVD with attractive menus allows viewers to navigate the contents easily. The process of authoring is similar to building a Web site. The menu screen on a DVD is comparable to the home page of a Web site, as it contains links to all the content on the DVD. Recent TrendWatch surveys report that 67 percent of U.S. corporate facilities use DVDs as a storage media. Half of corporate studios also perform DVD authoring. U.S. corporate film and video studios rank DVDs among their top projects that bring in new business, according to TrendWatch. A recent study asked staff at corporate facilities about their top new business opportunities. Sixty-eight percent said corporate and industrial videos brought in new business. Eighteen percent said DVDs and other multimedia projects provided a new business opportunity.
Benefits to DVD Authoring DVD is a practical option for a variety of reasons many of which are obvious. A DVD s 500 lines of resolution and 16- to 24- bit stereo digital audio give it increased clarity, detail, picture sharpness, and improved audio compared to VHS, which has a maximum resolution of only 240 lines. DVD provides a broad range of capabilities for delivering great viewing experiences with high-quality video and surround-sound audio. The inherent advantages of digital technology create added benefits for authoring. Multiple video files and photo slide shows using images from a digital camera, complete with pan-and-zoom effects and synchronized background music and narration, can be incorporated into DVDs. Chapter points in longer videos and place buttons on the menu can also be created, allowing viewers to jump directly to certain scenes. Other inherent advantages created by the digital domain include the fact that DVDs will not break, jam, or wear out as VHS tapes often do. DVDs can be played repeatedly without any loss of sound quality or picture. Viewers now have a new way to enjoy watching movies now, thanks to DVD authoring. Wide-screen DVDs can be created that completely fill a television screen and, when coupled with the improved video and audio quality, create a theater atmosphere. DVDs provide the ability to quickly navigate through program material and offer clear and fluid slow motion, multiple audio and video tracks, different languages, subtitles, Internet interactivity, games, DVD-ROM content, and 5.1 surround sound audio. There are two to four hours of broadcast quality video and audio when using DVD technology. DVDs also allow the user to jump to any scene or content instantly. Parental controls can also be used to create locked areas of the disc for security. Interesting video menus provide a useful means of accessing content. To realize all the technical benefits of DVDs, the human element cannot be underestimated. Forming collaborative working relationships with clients and understanding a client s vision for the finished DVD are critical elements of the DVD authoring process for postproduction houses.
Benefits to DVD Authoring Continued Design is another element that is an integral part of DVD authoring. This includes designing and creating still and motion elements, as well as DVD menus, special features, and introductions. Menu screens usually link to the main feature, chapters within the feature, additional scenes not contained in the feature, photographic slideshows, and additional audio content. The main menu screen can also contain links to submenus, which help avoid cluttering the main menu with too many options. Now, back to the technology. Conversion is another key feature to DVD authoring. Converting film or video material to MPEG2 format and converting audio to Dolby Digital format also is needed. MPEG2 video is the heart of the DVD. Everything that is seen on a DVD goes through the MPEG2 video encoding process. It is an essential step because if it doesn t go through the process, the disc would hold less than five minutes of video. An MPEG is a series of JPEGs. One frame about every half second is an I-frame, which is similar to a JPEG. Using that technique alone, called spatial compression, would fit only about 20 minutes of video on a DVD. As a result, a second technique called temporal compression is also used. Temporal compression relies on the fact that most video frames are quite similar to the frames immediately before and after them. MPEG then stores most of its frames ( B and P frames) with just information on what is different, rather than re-encoding everything. As a result, MPEG is more efficient with video containing modest motion and change, such as a conversation. It is also less efficient on rapid motion, such as a close shot of a baseball pitch. The more efficient the encoding is, the better quality will be achieved in a given number of bytes. The greater the quanitity of footage needed to store on a DVD is, the harder the encoder is will have to work to maintain quality. 4
Benefits to DVD Authoring Continued DVD authoring also allows the setup of additional features such as subtitles. Subtitle channels can be made so that the DVD can be used throughout the world in many different languages. Within the authoring application, each item is given the metaphor of a container. A container can hold any type of supported content and is linked to a menu selection, either on the main menu or a submenu. DVD authoring applications also usually support the creation of multiangle content, which is where viewers can decide to watch a different passage of video within the same soundtrack and subtitles. Multiple camera angles allow the user to direct the video. It also supports Dolby 5.1 Surround Sound. Writing scripts that enable and enhance the DVD allows for greater user activity and easier DVD navigation. Authoring occurs when all of the above elements are combined to form the final DVD. The audio and video pieces, as well as the menus and scripts, are combined. Chapter markers are created for DVD navigation, and remote control elements are programmed. Copy protection is added, and the DVD is tested and proofed. This is when the content is multiplexed, or linked together, and the master disc can be burned. Duplication The principle behind duplication has not changed, even as technology presses on. As was the case with VHS in 1995, duplication in 2005 focuses on making multiple copies from a master in a costeffective manner. Today, duplication refers to the procedure of creating more DVD-R copies of a DVD. It is a process that is done to manufacture smaller runs typically 500 or less of DVDs. The DVD-R media is loaded into burners. The information is digitally extracted from the DVD-R master source and transferred to blank discs. The information is then verified and the copy is accepted. 5