Introduction to HD DVD Authoring

 

Christopher Diggins

Microsoft Corporation

April 2006

 

Applies to:

   Microsoft® HD DVD Interactivity Jumpstart

 

Summary: Explains the basics of high-definition digital video disc (HD DVD) content authoring and workflow using the HD DVD Interactivity Jumpstart on a desktop computer. This document assumes some familiarity with the basics of DVD content authoring.

 

Contents

Introduction

HD DVD Advanced Content

HD DVD Video Disc Contents

Workflow

   Plan the Video Experience

   Acquire and Examine the Assets

   Implement the Interactive Experience

   Test and Debug

   Create Output

For More Information

Introduction

High Definition DVD (HD DVD) is a next-generation DVD format with the ability to play High Definition (HD) video content and to offer enhanced user experiences.

The production process and workflow for HD DVD is similar to classic DVD, however the technology for authoring the user experience has been completely modernized.

This document covers the basic steps for developing and testing HD DVD applications on a desktop computer, and provides an overview of the workflow.

HD DVD Advanced Content

Advanced Content refers to the dramatically improved graphics, interactivity, and animation capabilities that are available for content authors in HD DVD.

The technology for authoring Advanced Content is based on the open-standard technologies of ECMAScript (also known as JScript) and XML, which are also used in the construction of Web pages. This was done specifically so that HD DVD content authoring would be easier to learn for experienced Web page designers.

XML is a markup language, like HTML, which is more flexible and can be used to describe virtually any kind of data. In an Advanced Application, XML is used to describe the contents of the video disc, the order and timing of animated elements, the style and positioning of graphical and technical elements, and so forth.

The ECMAScript component of Advanced Content offers an even finer level of control over the user experience than can be achieved by XML alone, although technically, an entire HD DVD application could be designed without the use of any script.

ECMAScript is often referred to as JScript or JavaScript, although technically these two languages are both extensions of the ECMA-262 standard. HD DVD uses its own subset of the ECMAScript 3rd Edition Compact Profile (ES-CP).

HD DVD Video Disc Contents

An HD DVD Advanced Application is organized using a Windows-style directory system to store all necessary files (video, graphic, script, mark-up, and so on). The HD DVD application has a root directory containing two primary subdirectories. These subdirectories are named HVDVD_TS and ADV_OBJ. The HVDVD_TS directory contains the primary video title sets. The ADV_OBJ directory contains the DISCID.DAT configuration file, secondary video set, playlist files, application files (manifest files, mark-up files, and script files), advanced subtitles, and non-video assets (graphics, audio files, and fonts), which can be arranged as desired in subdirectories of the ADV_OBJ directory.

Workflow

The process of creating HD DVD Advanced Content involves a somewhat different workflow from classic DVD. The following topics outline the steps involved in producing a category 2 HD DVD.

  • Plan the Video Experience
  • Acquire and Examine the Assets
  • Implement the Interactive Experience
  • Test and Debug
  • Create Output

Plan the Video Experience

Planning the user experience for HD DVD is even more important than for classic DVD. With the increased opportunity for user interaction, careful planning becomes more important. You want to catch design errors or inconsistencies in the early phases of development, when they are less expensive to fix.

The first step in planning the video experience is to create a model using a storyboard or flowchart. A model is useful for detecting states that are difficult or impossible to reach, or states that are dead ends and offer no opportunity to return to a previous state.

While planning the user experience, consider the following:

  • FBI warning screens - The FBI warning screen should not be skippable.
  • Studio logo - The studio logo can be made not skippable as well.
  • Previews - The previews should be skippable.
  • Extras - Will you include things like bloopers, trailers, music-videos, mini-games, a "making-of" video, and so on?
  • Languages - You need to choose the languages that will be supported by the menus, audio tracks, extras, and subtitles.
  • Director's commentary - With HD DVD, the director's commentary can be turned on or off during playback, and can support advanced functionality such as picture-in-picture with sliding controls for transparency, positioning, size, and audio volume.
  • Bookmarking system - HD DVD enables you to create a bookmarking system, so that the user can easily return to a previous favorite position in the video.

Another useful step in planning the experience of videos is to create visual prototypes and motion graphics using tools like Microsoft Expressions, Adobe After Effects, or MacroMedia Director. These help reduce costs during the design process by providing a storyboard of what the user will experience. Graphical elements can also be cut directly from the prototypes and motion graphics after they are approved, and used in the final product if they are of sufficiently high resolution.

Acquire and Examine the Assets

Acquiring the assets for a video disc should be done as early as possible, so that they can be verified and encoded. The typical assets for an HD DVD are:

  • Video - Video assets can be in the following formats: SMPTE VC-1, MPEG-4 AVC, or MPEG-2 HL (a higher resolution version of MPEG-2 ML). Typically, the main video will be in 1920 x 1080p resolution, and secondary video (such as picture-in-picture) will be standard definition.
  • Audio - Audio assets can be in the following formats: linear PCM, Dolby TrueHD, DTS HD, and MPEG Audio.
  • Graphics - Graphics can be in JPEG, PNG, or MNG format.
  • Fonts - All fonts used must be included on the disc in an OpenType (.TTF or .OTF) format. Font files may require licensing.

Due to the high resolution of HD DVD players and displays, the graphics and video assets need to be of the highest possible quality. HD displays can reveal flaws that are not perceptible on SD displays.

Implement the Interactive Experience

An Advanced Application is implemented using a combination of XML markup files and optional ECMAScript script files (.JS). The XML markup files consist of playlist files (.XPL), application manifest files (.XMF), application markup files (.XMU), and advanced subtitle files (.XAS).

Microsoft offers downloadable utilities for simulating and validating HD DVD applications. For more information about these tools, see For More Information.

The HDDVDValidator.exe program validates the markup and script, and can be used to identify and fix many common errors. This tool comes with a separate file, jscript.dll, which, when installed, enables more detailed error reporting. 

The iHDSim.exe program is an Advanced Content simulator. It simulates an HD DVD Advanced Application on the desktop computer. This enables testing of the Advanced Content as it is being developed. The iHDSim.exe is not intended as a video playback mechanism, an optical disc simulator, performance simulator, or replacement for consumer electronics players. It is only an aid to make the authoring of interactive experiences easier.

The only official documentation for developing HD DVD applications is the HD DVD specification, released by the DVD Format / Logo Licensing Corporation. An HD DVD Programming Guide is also available, from Microsoft. For information about both of these documents, see For More Information.

Test and Debug

You should test as early as possible during development, and do so frequently.

Some hints for testing and debugging:

  • Use placeholder video to improve playback performance.
  • Use a script debugger such as the Microsoft Script Debugger. To download this tool, see For More Information.

Create Output

When an HD DVD application is completed, the multiplexing, mastering, formatting, and replication stages of the process can be performed by a service company or by using commercial third-party tools.

For More Information

  • For more information about XML, see the W3C XML Web page (http://www.w3.org/XML/).
  • For more information about ECMAScript 3rd Edition Compact Profile, see ECMA International Standards Web page (http://www.ecma-international.org/publications/standards/Ecma-327.htm).
  • To order the official HD DVD specification, see the (http://www.dvdfllc.co.jp/).
  • For the latest validation and simulation tools, online discussion forums, and an HD DVD Programming Guide, see the Microsoft HD DVD Web page (http://go.microsoft.com/fwlink/?linkid=64494).
  • For more technical information on HD DVD, see the DVD Forum site (http://www.dvdforum.org/hddvd-tech.htm).

Web addresses can change, so you might be unable to connect to the Web site or sites mentioned here.

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