PATENT DOCUMENT

Publication Number: US-8208789-B2
Application Number: US-53588506-A
Country: US
Kind Code: B2

Title: Video program authoring systems and methods

Abstract:
Video program authoring systems and methods in a processor-based system removes an author from consideration of low-level configuration functions during authoring. The authoring systems and methods provide an authoring engine having an interactive graphical authoring interface, a data management engine, an emulator, a compiler, a multiplexer and a simulator. Using summary authoring data, the compiler builds a skeleton-faun layout structure comprising abstracted components that include movie chapters, menu buttons and command segements. The compiler then resolves abstracted connections between combinations of the abstracted components to produce a video program. Instructions associated with the command segments and a configuration of the command segments within a video program video space and domain structure are abstracted.

Claims:
1. A method for compiling an authored video program comprising the steps of: generating a predetermined program chain (“PGC”) data structure from a plurality of command segments associated with a plurality of user abstraction components, wherein the user abstraction components comprise high level command segments not disclosed in an authoring standard, and wherein a PGC data structure defines a set of low-level command combinations in accordance with the authoring standard; and authoring a video program by resolving abstracted connections between combinations of user abstracted components and respective extracted PGC&#39;s from the plurality of user abstracted components, wherein the plurality of user abstracted components includes menu buttons, movie chapters and interconnected command segments, and instructions associated with the plurality of command segments and a configuration of the command segments within a video program video space and domain structure are abstracted. 
     
     
       2. A method according to  claim 1 , wherein the menu buttons are associated with one or more authored menus, and wherein the step of creating includes: quantifying the one or more authored menus, and quantifying the menu buttons associated with each authored menu; and forming the PGC data structure from an integer multiple of command segments for each authored menu, wherein each of the multiple command segments includes at least one instruction for each menu button in each authored menu. 
     
     
       3. A method according to  claim 2 , wherein the step of authoring includes: receiving connection information including authored source and destination designations for the one or more authored menus and the menu buttons, and merging the connection information into the abstracted instructions in corresponding abstracted command segments to produce the video program. 
     
     
       4. A method according to  claim 3 , wherein the step of receiving connection information includes querying at least one of a button and a chapter for source and target information. 
     
     
       5. A method according to  claim 4 , wherein the step of merging includes replacing instructions with corresponding source and target information. 
     
     
       6. A method according to  claim 4 , wherein the step of receiving connection information further includes: obtaining a connection object having a source index referring to a button; querying the connection object for a target index based on the source index; and querying at least one of a button and a chapter for source and target information based on the source and target indices. 
     
     
       7. A method according to  claim 3 , wherein the abstracted instructions include a predetermined value until the step of merging replaces the predetermined value with corresponding connection information. 
     
     
       8. A method according to  claim 7 , wherein the predetermined value is a no operation value. 
     
     
       9. A method according to  claim 3 , further comprising the step of replacing the connection information with a corresponding connected element identifier. 
     
     
       10. A method according to  claim 8 , wherein the integer multiple is independently defined for each of the one or more PGC data structures and wherein each of the plurality of command segments includes a video manager domain associated with at least one of the one or more authored menus. 
     
     
       11. A method according to  claim 2 , wherein the integer is independently defined for each of the one or more authored menus and wherein the integer is 1 for at least one authored menu. 
     
     
       12. A method according to  claim 1 , wherein the step of creating includes: forming the PGC data structure having indices therein; resolving connections associated with the indices to obtain element identifiers; and replacing the indices in the PGC data structure with the element identifiers. 
     
     
       13. A method according to  claim 12 , wherein the indices are formed with a predetermined value. 
     
     
       14. A method according to  claim 13 , wherein the predetermined value is a no-op value. 
     
     
       15. A method according to  claim 13 , wherein replacing each of the indices with an associated element identifier comprises replacing the predetermined value with the associated element identifier. 
     
     
       16. A method according to any of  claim 12 , wherein resolving connections includes: determining a connection object referencing a button as its source; obtaining a pointer associated with the connection object for identifying a target index of the button; and determining source and target identifiers corresponding to the source and target indices. 
     
     
       17. A method according to  claim 16 , wherein the step of replacing the indices includes replacing two of the indices with corresponding source and target identifiers. 
     
     
       18. A method according to  claim 1 , wherein the PGC data structure comprises: command segments having predetermined command structures including: at least one movie router command segment, a plurality of menu command segments corresponding to authored menus associated with the menu buttons; a plurality of end command router command segments, each end command router command segment corresponding to an authored movie; one or more movie display command segments each movie display command segment corresponding to an authored movie; and a plurality of remote key router command segments, each remote key router command segment corresponding to an authored menu key response. 
     
     
       19. A method according to  claim 18 , wherein each of the menu command segments comprises a menu display command segment for displaying a menu and a button router command segment for initiating an authored action when a corresponding user menu button is depressed. 
     
     
       20. A method according to  claim 18 , wherein the PGC data structure further comprises a video manager and wherein the video manager includes the at least one movie router command segment, the plurality of menu command segments and the plurality of end command router command segments. 
     
     
       21. A method according to  claim 18 , wherein a presentation command segment is formed for each authored movie and wherein each presentation command segment comprises a movie display command segment and a number of remote key router command segments corresponding to a total number of chapters authored in a corresponding movie. 
     
     
       22. A method according to  claim 18 , wherein each of the plurality of remote key router command segments corresponds to a related chapter point in a corresponding movie. 
     
     
       23. A system for video program authoring, the system comprising: means for generating a predetermined program chain (“PGC”) data structure from a plurality of command segments associated with a plurality of user abstraction components, wherein the user abstraction components comprise high level command segments not disclosed in an authoring standard, and wherein a PGC data structure defines a set of low-level command combinations in accordance with the authoring standard; and means for authoring a video program by resolving abstracted connections between combinations of user abstracted components and respective extracted PGC&#39;s from the plurality of user abstracted components, wherein the plurality of user abstracted components includes menu buttons, movie chapters and interconnected command segments, and instructions associated with the plurality of command segments and a configuration of the command segments within a video space and domain structure of the video program are abstracted. 
     
     
       24. A system according to  claim 23 , wherein the menu buttons are associated with one or more authored menus, and wherein the means for creating the PGC data structure is for: quantifying the one or more authored menus, quantifying the menu buttons associated with each of the one or more menus, and forming the PGC data structure from an integer multiple of command segments for each authored menu, wherein each of the multiple command segments includes at least one instruction for each menu button in the each authored menu. 
     
     
       25. A system according to  claim 24 , wherein the authoring means is for receiving connection information including authored source and destination designations for the one or more authored menus and the menu buttons, and merging the connection information into instructions in corresponding command segments to produce the video program. 
     
     
       26. A system according to  claim 23 , wherein the PGC data structure initially has indices therein, wherein the indices in the PGC data structure are associated with element identifiers. 
     
     
       27. A system according to  claim 23 , wherein the PGC data structure comprises: command segments having predetermined command structures including: at least one movie router command segment; a plurality of menu command segments corresponding to authored menus associated with the menu buttons; a plurality of end command router command segments, each command router command segment corresponding to an authored movie; one or more movie display command segments each movie display command segment corresponding to an authored movie; and a plurality of remote key router command segments, each remote key router command segment corresponding to an authored menu key response. 
     
     
       28. A system according to  claim 27 , wherein each of the menu command segments comprises a menu display command segment for displaying a menu and a button router command segment for initiating an authored action when a corresponding user menu button is depressed. 
     
     
       29. A system according to  claim 27 , wherein the PGC data structure further comprises a video manager wherein the video manager includes the at last one movie roster command segment, the plurality of menu command segments and the plurality of end command router command segments. 
     
     
       30. According to  claim 27 , wherein each authored movie is associated with a presentation command segment and wherein each presentation command segment comprises a movie display command segment and a number of remote key router command segments corresponding to a total number of chapters authored in a corresponding movie.

Description:
CLAIM OF PRIORITY 
     This is a continuation of U.S. application Ser. No. 10/213,025 filed Aug. 5, 2002, which issued as U.S. Pat. No. 7,200,836, which is a continuation of U.S. application Ser. No. 09/010,267 filed Jan. 21, 1998, which issued as U.S. Pat. No. 6,453,459, all of which are incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to mass data storage and retrieval, and more particularly to apparatus and methods for authoring a digital versatile disk. 
     BACKGROUND OF THE INVENTION 
     New mass data storage means provide not only for storing greater amounts of multimedia and other information, but also for more interactive data retrieval by consumers. For example, one such storage means is espoused by the “DVD Specification for Read-Only Disc, Physical, File Format and Video Specifications” (DVD Consortium 1997), hereinafter referred to as the “DVD Specification”. Other examples include further DVD-related technologies (e.g. DVD-Audio, DVD-RAM, etc.) as well as non-DVD technologies. 
     The Physical and File System portions of the DVD Specification defines the physical encoding and organization of data for storage on read-only digital versatile disk (“DVD ROM”) media. The Video portion of the DVD Specification defines a data set (“DVD-Video data set”) with which pre-recorded DVD-Video discs must confirm in order to assure proper reading, decoding and playback when inserted into a media reader/decoder (“DVD-player”). More specifically, the Video portion specifies how “control data” and audio/video “presentation data” are encoded and ordered within the data set. The control data determines how presentation of audio/video data will proceed when the disc is played back on a DVD-player and consists of low-level state information, data structures and instruction sets which govern what kinds of functions and user operations a DVD player can perform. 
     The DVD Specification is further hereby fully incorporated herein by reference as if repeated verbatim immediately hereinafter. 
     The process of encoding and authoring a DVD movie title, as currently practiced, includes a number of separate and distinct steps requiring similarly separate and distinct expertise. After movie production, raw film and/or video footage is edited, the soundtrack is edited and mixed, and a movie film or video master is created. This master is subsequently digitized, encoded as video and audio streams and stored as data files. In accordance with the DVD Specification, the Moving Pictures Expert Group (“MPEG-1 or MPEG-2”) format is used to encode the video streams and any one or more of a number of specified formats (e.g. MPEG-1 or MPEG-2 Audio, Dolby AC-3, PCM) is used to encode the audio streams. Graphic data (i.e. still or moving images for creating menus and other presentation data) is also created and stored in conventional graphic files. Finally, authoring guidelines, the encoded audio and video stream files and the graphic files are gathered for the authoring phase. 
     During authoring, a DVD author utilizes the guidelines and file information to construct a DVD movie-title. The authored movie-title determines what a user of a resultant movie title will see and hear, and what kinds of interactions the user can command when the movie title is played back by a DVD-player. The author organizes the video, audio and (often author-created) subtitle files, divides the movie into segments (“chapters”), creates menus, and specifies low-level instructions. The low-level instructions will set parameters, define fixed or optional jump points and their destinations and determine the order and options by which playback of still pictures, movie chapters and associated audio tracks will proceed based on the user&#39;s menu selections and/or use of other DVD-player controls (i.e. typically using a remote control device). 
     Once authored, the author&#39;s organizational decisions, subtitle, chapter and menu decisions, and low-level instructions are compiled into control data, and the encoded video, audio and subtitle streams, as well as the graphic data files, are multiplexed into presentation data, which together constitute the DVD-Video data set. Finally, this DVD-Video data is converted into a “disc image layout” file, which can be used to burn a “write-once DVD-R” disc, or can be stored onto a tape to send to a DVD-ROM manufacturing plant for creating a “master” disc, which can then be used for replication. 
     Conventional DVD authoring systems comprise a computer system running an application-specific DVD authoring program. An exemplary, widely used conventional DVD authoring system is Scenarist-II. 
     Scenarist-II is essentially an attempted, nearly direct embodiment of the DVD Specification. Using Scenarist-II, an author organizes data streams, and constructs menus and DVD structures according to the DVD Specification. Top level structures (i.e. up to 99 “VTSs” and “VTSMs”, a “VMG” and a VMGM”) are constructed by selecting the structure type and then populating the structure with one or more low-level command segments (“program chains” or “PGCs”) including movie or menu references. Throughout this process, the author also selects from among available data formats, as well as from among the numerous DVD options and requisite parameters, using a number of provided lists and other data and parameter representations. Stated alternatively, all structures and PGC parameters, capabilities and references must be fully specified by the author on an ongoing basis during authoring. 
     Unfortunately, the DVD Specification is very complex, as are the conventional programs that attempt to embody it. Available options are extensive, as are the numerous listings of options and parameters within programs such as Scenarist-II. The potential combinations of structures and PGCs are also extensive, and many such combinations will not ultimately result in functional DVD movie-titles. 
     To make matters more difficult, the PGCs (i.e. basic and frequent constructs of the DVD Specification and therefore of programs such as Scenarist-II) are counter-intuitive. Often, many PGCs (including both operative and so-called “dummy” PGCs) must be used in specific combinations to provide a DVD consumer with even the most basic control capabilities. Limitations imposed by the DVD Specification must also be considered throughout the process. Thus, errors in planning and/or programming might well remain undetected until after a substantial number of structures are formed. In addition, given the sheer number of structures, PGCs, commands, options and parameters involved, identifying, locating and correcting errors is difficult and time-consuming. 
     Consequently, while providing extensive low-level control and an expedient authoring-to-compilation correspondence, conventional authoring systems require an extensive expertise with regard to both the DVD Specification and the authoring system itself. Further, even assuming such expertise, authoring is extremely time-consuming and is therefore typically very costly. In addition, even assuming resolution of other factors, the time and expertise required would likely prevent authoring of even a preliminary movie-title as a directorial aid during the movie production process. 
     A further disadvantage of conventional authoring systems is that experimentation and all but necessary modification are often compromised due to time and cost considerations. Thus, many DVD movie titles (due to limited budget to support expensive authoring time) provide a DVD consumer with only minimal playback control, navigation flexibility and interactivity. 
     Accordingly, there is a need for an authoring system and method that enables DVD authoring in a manner removed from the structures and low-level instruction sets of the DVD Specification, thereby reducing the time, cost and complexity of the authoring process. 
     There is further a need for such an apparatus and method whereby authoring can be conducted in an intuitive manner, while maximizing flexibility and access to features provided by or otherwise not in conflict with the DVD Specification. 
     SUMMARY OF THE INVENTION 
     The present invention provides a data processing-system based authoring system and method that essentially removes an author from consideration of the structures and low-level instruction sets of the DVD Specification. More specifically, the present authoring system removes the ordered tasks associated with creating DVD structures and programming PGCs, and replaces them instead with an interactive, intuitive and graphical authoring environment. 
     The present invention further provides for flexible program flow in response to control events. Many interactive controls, menu button destinations and other features that are possible in accordance with the DVD Specification can be specified by an author in multiple instances and according to quick, intuitive and interactively modifiable selections. Thus the invention facilitates authoring of a DVD movie title by even an inexperienced author with context sensitive responsiveness to DVD consumer instructions and other DVD player-generated events. 
     Accordingly, a preferred embodiment of the present invention comprises an authoring engine having an integrated interface with which an author performs the above tasks a data management engine for storing and recalling authoring information, a simulator for viewing progressive and/or comparatively authored movie titles prior to compiling, a compiler, a multiplexer and an emulator for viewing authored movie titles after compiling and multiplexing. 
     Included within and facilitating the ability of these elements to remove an author from the DVD Specification are several abstractions. Preferably, the interface provides such “user abstractions” as arranging movies (i.e. data streams including video, audio, subtitles, chapter points and other elements), creating menu layouts (i.e. menus, menu buttons and still or moving images with or without sound) and specifying connections among these arrangements and layouts, each in a simple and intuitive, yet highly flexible way. Further abstractions include a network or connection-switching abstraction and a number of control and router PGC abstractions from which the connection-switching abstraction is constructed. 
     Authoring instructions entered through the interface are preferably broken down into component parts and stored by the data management engine. The invoked compiler, using only summary authoring information, preferably constructs a skeleton form PGC layout structure comprised of PGC abstractions corresponding to the number of authored movie elements. The compiler then completes the layout structure according to author-selected and default source-target connections. 
     Further according to a preferred embodiment, during playback of a resultant DVD movie title, a source PGC abstraction is invoked in response to DVD player and/or consumer instructions. The source PGC abstraction determines target information and transfers control, through necessary router PGC abstractions, to a target PGC abstraction. The target, in accordance with the target information, plays a movie chapter, displays a menu, or sets and/or modifies one or more DVD parameter. 
     These and other objects, advantages and benefits of the present invention will become apparent from the drawings and specification that follow. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is functional block diagram generally illustrating an authoring system according to a preferred embodiment of the invention; 
         FIG. 2  is a functional block diagram illustrating in more detail a preferred authoring program of the authoring system shown in  FIG. 1 , according to the invention; 
         FIG. 3  is a screenshot of a preferred performance element arrangement interface portion of the  FIG. 2  authoring program, according to the invention; 
         FIG. 4  is a blowup of the  FIG. 3  screenshot showing, in more detail, a preferred authoring toolbar for accessing authoring program modules and functions; 
         FIG. 5  is a flowchart illustrating an exemplary method used by an author to create a performance element arrangement using the performance element arrangement interface portion of  FIG. 3 ; 
         FIG. 6   a  is a flowchart illustrating preferred responses of the authoring program to authoring while the performance element arrangement interface portion of  FIG. 3  is active; 
         FIG. 6   b  is a flowchart further illustrating preferred responses of the authoring engine to authoring while the performance element arrangement interface portion of  FIG. 3  is active; 
         FIG. 7  is a screenshot of a menu element layout interface portion of the  FIG. 2  authoring program, according to the invention; 
         FIG. 8  is a flowchart illustrating an exemplary method used by an author to create a menu layout using the menu element layout interface portion of  FIG. 7 ; 
         FIG. 9  is a screenshot of a preferred connections interface portion of the  FIG. 2  authoring program, according to the invention; 
         FIG. 10  is a screenshot of a preferred simulator interface portion of the  FIG. 2  authoring program, according to the invention; 
         FIG. 11  is a functional block diagram of a preferred data management engine according to the invention; 
         FIG. 12   a  is a flowchart showing generally the operation of a preferred compiler according to the invention; 
         FIG. 12   b  is a flowchart showing how a compiler according to the invention preferably constructs a skeleton-form PGC layout structure; 
         FIG. 12   c  is a flowchart showing how the compiler preferably resolves source-target connections and substitutes those connections for null operations in a preferred skeleton-form PGC layout structure, according to the invention; 
         FIG. 13  is a block diagram showing the format of a preferred PGC layout structure according to the invention; 
         FIG. 14  is a functional block diagram showing a preferred connection-switching abstraction according to the invention; 
         FIG. 15  is a flowchart showing a preferred operation of the connection-switching abstraction of  FIG. 14 , according to the invention; 
     
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
     For clarity sake, the discussed embodiment herein will be directed primarily toward storage according to the DVD Specification, and more specifically at authoring motion picture DVD ROMS (“movie titles”). It should be understood, however, that the present invention relates to a broad range of program and data storage and retrieval utilizing a variety of media, only a subset of which will be specifically identified herein. The types of DVD ROMS which can be authored are further in no way limited to movie titles. Other examples include but are not limited to music videos, documentaries, educational videos, corporate training, medical applications and other continuous play or interactive information which utilizes audio, video and/or other presentation data. 
     As illustrated in  FIG. 1 , a preferred embodiment of authoring system  100  according to the invention preferably comprises electrically connected hardware elements including input devices  110 , processor  115 , memory  120 , storage  125 , MPEG encoder/decoder  130 , video I/O device  135  and audio I/O device  140 . Authoring system  100  further comprises software elements including operating system  150 , authoring engine  160 , data management engine  165 , compiler  170 , simulator  175 , emulator  180  and multiplexer  185 . 
     It will be apparent to those skilled in the art that several variations of the authoring system elements are contemplated and within the intended scope of the present invention. For example, given processor and computer performance variations and ongoing technological advancements, hardware elements such as MPEG encoder/decoder  130  may be embodied in software or in a combination of hardware and software. Similarly, software elements such as multiplexer  185  may be embodied in hardware or in a combination of hardware and software. Further, while connection to other computing devices is indicated as network I/O  145 , wired, wireless, modem and/or other connection or connections to other computing devices (including but not limited to local area networks, wide area networks and the internet) might be utilized. A further example is that the use of distributed processing, multiple site viewing, information forwarding, collaboration, remote information retrieval and merging, and related capabilities are each contemplated. Various operating systems and data processing systems can also be utilized, however at least a conventional multitasking operating system such as Windows95® or Windows NT® (trademarks of Microsoft, Inc.) running on an IBM® (trademark to International Business Machines) compatible computer is preferred and will be presumed for the discussion herein. Input devices  110  can comprise any number of devices and/or device types for inputting commands and/or data, including but not limited to a keyboard, mouse, and/or speech recognition. (The use of a keyboard and a mouse are exemplified throughout the discussion that follows.) 
     The  FIG. 2  block diagram illustrates in greater functional detail an authoring program  201  of the preferred authoring system of  FIG. 1 . As shown, authoring program  201  comprises authoring engine  160  (which includes interface  160   a ), data management engine  165 , compiler  170 , simulator  175 , emulator  180 , multiplexer  185 , output DVD data storage  290  and layout formatter  187 , user abstractions  285  and PGC abstractions  287 . 
     It is discovered through examination of the features supported by DVD players that the basic presentation data types and consumer controls available to an author of DVD movie titles can be generalized and then reconstructed as abstracted user data types and controls. Further, despite the complexity of the DVD Specification, many of its programming constructs can also be generalized and then reconstructed as abstracted DVD program chains (“PGCs”) operating within a further abstracted network or connection-switching superstructure. Such user abstractions  285  and PGC abstractions  287 , as integrated into authoring engine  160 , data management engine  165  and compiler  170  (as illustrated), effectively remove an author using authoring program  201  from consideration of DVD Specification  205 . These abstractions further remove such consideration without unduly limiting, for most practical purposes, authoring flexibility, PGC efficiency or interactive responsiveness of a resultant DVD-ROM, among other factors. In addition, these abstractions provide a framework of re-useable components that are readily adaptable to further modification for providing improvements, and for re-use in a variety other DVD and non-DVD applications. 
     Authoring program  201  is preferably implemented in C++, an object-oriented language, for reliability, updateability and other known generalized advantages of object-oriented programming. Those skilled in the computer arts will appreciate however, that despite such advantages, other environments and/or programming languages of various object-oriented and non-object-oriented types can also be utilized. 
     Operationally, an author enters authoring information and instructions for activating and controlling authoring program  201  through interface portion  160   a  of authoring engine  160 . Authoring engine  160  interactively receives entered information and commands by correspondingly adjusting interface portion  160   a , invoking a further authoring program module, sending entered authoring information to data management engine  165 , retrieving authored information from data management engine  165 , and sending and/or retrieving presentation data from presentation data storage  203 . Data management engine  165  responds to authoring engine  160  by receiving and storing authored information from authoring engine  160  and/or sending information, which it retrieves from storage (and/or from a remote source), to authoring engine  160 . Simulator  175  responds to authoring engine  160  by retrieving authoring data from data management engine  165 , retrieving multiplexed presentation data from multiplexer, and simulating an authored DVD-ROM in conjunction with interface  160   a.    
     Compiler  170  responds to authoring engine  160  by retrieving authored information from data management engine  165 , compiling the information and storing the compiled information (“.ifo files”) in output DVD data storage  290 . Emulator  180  responds to authoring engine  160  by retrieving compiled data from output DVD data storage  290 , retrieving multiplexed data from output DVD data storage  290  and emulating an authored DVD-ROM in conjunction with interface  160   a . Multiplexer  185  responds to authoring engine  160  by receiving DVD parameter information from compiler  170 , retrieving presentation data from presentation data storage  203  and combining the retrieved information and data in accordance DVD Specification  205 . Multiplexer  185  then stores the combined information and data (“DVD data stream” or “.vob file”) in output DVD data storage  290 . Layout formatter  187  retrieves the vob files and ifo files from output DVD data storage  290  and combines these files into a single “disc image” file, which it then stores in disc image file storage  207 . The disc image file can then be sent through network I/O  145  ( FIG. 1 ) to additional apparatus for further review, processing and/or for burning one or more DVD-ROMs  207 . 
       FIGS. 3 through 10 , with reference to  FIG. 2 , illustrate how an interface according to the invention enables an author to assemble a movie title essentially removed from DVD programming specifications  207  ( FIG. 2 ) of the DVD Specification. Preferred interface  160   a  is illustrated as an application running under a Windows95® or Windows NT® (trademark of Microsoft, Corp.) operating system. 
     The  FIG. 3  screenshot illustrates a preferred authoring window  300 , which an author can utilize to select an arrangement of audio-visual material including video segments (“video clips”), audio segments (“audio clips”) and subtitles (hereinafter referred to collectively as “performance data”). 
     Authoring window  300  is divided into movable, modifiable and replaceable groupings or “views” and “panels” including presentation data panel  301 , performance assembly panel  302 , assembled elements panel  307 , log panel  308  and preview video panel  309 . Assembly panel  302  is further divided into video assembly portion  320 , audio assembly portion  330  and subtitle assembly portion  340  (which are collectively referred to herein as performance view  303 ), and performance tools portion  360 . Authoring window  300  also includes authoring toolbar  399   a  and menu bar  399   b . For clarity sake, the following discussion assumes that a single, continuous movie is being authored (i.e. a movie having component video, audio and subtitle data streams each of which begins at the start of the movie and ends at the conclusion of the movie). 
     Presentation data panel  301  provides a display listing for each presentation data file that an author has selected and loaded for use in assembling movies and menus either during a current authoring session or when continuing a re-initiated, prior authoring session. File listings include file name  311 , file duration  313 , and file type  315  parameters. File name  311  lists the name of a file. File duration  313  lists the playback duration of files such as video data files and audio data files. File type  315  alternatively lists a file format, which is generally indicated by a filename extension, or a recognized data type such as “video” data or “audio” data. As will be further discussed, presentation data file listings can be used interactively during an authoring session. 
     Performance assembly view  303  of performance assembly panel  302  is used by an author to graphically and interactively assemble loaded video and/or audio data, to add and assemble subtitles, and/or to add chapter points. For these purposes, performance view  303  includes video assembly portion  320 , audio assembly portion  330 , subtitle assembly portion  340  and chapter assembly portion  350  respectively. Video assembly portion  320  is used by an author to assemble graphic objects referencing stored video data files (“video clips”). As discussed, these files, once initially selected, are listed in presentation data panel  301 . Video frame thumbnails  323   a  and  323   b  are indicative of chapter points as will be further discussed herein. 
     Audio assembly portion  330  of performance assembly panel  302  is used by an author to receive graphic objects referencing stored audio data files (“audio clips”). As with video clips, audio clips, once selected for use, are listed in and selected from presentation data panel  301  for arrangement purposes. Up to eight (alternate language) audio data streams or audio “tracks”, exemplified by audio tracks  331   a  through  331   c , are available in accordance with DVD Specification  205  ( FIG. 2 ). Audio bars  332   a  and  332   b , which represent author-arranged audio clips, have a length that reflects the playback time of the audio data represented. Separators  333  are further indicators of chapter points, as with video frame thumbnails  323   a  and  323   b  of video assembly portion  320 . Audio tracks  332   a  through  332   c  further include audio encoding indicators  334   a  audio format indicators  334   b , track number indicators  335  and selected language indicators  336 , which are indicative respectively of audio data file encoding and playback format, selectable audio track number  336  and modifiable language label  335 . Language labels  335  can be set by author selection or, as is expected, automatically by recognition of languages spoken in a recorded dialog of a respective audio track. 
     Subtitle assembly portion  340  provides for entry, retrieval and/or editing of up to thirty-two (alternate language) frame-based subtitle sequences, as exemplified by tracks  341   a  and  341   b . Exemplary subtitle frames  342   a  and  342   b  illustrate textual subtitle contents. Subtitles are entered in a conventional manner using a conventional text editor (not shown) which is invoked by activating a subtitle flame (e.g. by menu selection or double-clicking) and/or by retrieving a pre-existing subtitle file using, for example, presentation data panel  301 . As with audio assembly portion  330 , subtitle portion  340  includes selectable track numbers and modifiable language label indicators. 
     Performance assembly view  303  also includes chapter assembly portion  350 , which is used by an author to graphically and interactively assemble chapter points. Chapter assembly portion  350  includes wall clock  351 , reference offset clock  352 , author-assembled chapter indicators  353   a  through  353   c , chapter time indicators  354   a  through  354   c  and reference time indicators  355   a  through  355   c . Wall clock  351  indicates a time within a video clip corresponding to a cursor position over chapter portion  350  of assembly panel  302 . Offset clock  352  indicates the start time of a currently indicated video clip according to the reference timecode of a master tape (i.e. from which the video data file was created). Chapter indicators  353   a  through  353   c  show chapter points (i.e. points to which a DVD-ROM consumer can advance) as arranged during authoring. Chapter time indicators  354   a  through  354   c  and reference time indicators  355   a  through  355   c  display the elapsed time of corresponding selected chapter points from the start of a movie and from the start of a clip respectively. Reference times are typically recorded (and thus can be selectively retrieved and displayed) utilizing Society of Motion Pictures and Television (“SMPTE”) timecode. 
     As noted earlier, performance assembly panel  302  and the other panels and views of authoring window  300  are replaceable. Tabs  302   a  provide one alternative control structure for selectively switching between initiated or “open” authoring tasks, for example, to alternate between assembling presentation data of multiple movies, for creating menu layouts, and/or for other authoring tasks. Other control structures include menu options (not shown) for selectively decoupling panels and transport enabling controls ( 362   a  through  362   c  and  363   a  through  363   b ), and further for re-coupling in the illustrated default arrangement, in an author-selectable arrangement and/or interactively by an author. Panels can be resized and/or re-arranged among other window capabilities, as will be understood by those skilled in the art in view of the discussion herein. 
     Assembly tools portion  360  of performance assembly panel  302  comprises selectable zoom controls  361   a  through  361   c , preview transport buttons including stop  362   a , play  362   b  and frame advance  362   c , preview transport start time selector  363   a  and stop time selector  363   b , selected clip indicator  364   a  and total clips indicator  364   b . Zoom controls  361   a  through  361   c  are used respectively for increasing the viewable data range of a selected area within performance assembly view  303  of performance assembly panel  302 , for selecting a portion of performance assembly view  302  for such viewing, and for decreasing the viewable data range. Transport controls  362   a  through  362   c  provide video playback control when previewing a video clip, audio clip and/or subtitle data using preview video panel  309 , or when selecting a representative video frame in a video clip as a preview thumbnail (as with exemplary thumbnails  323   a  and  323   b ). Transport control  362   a  halts video, audio and/or subtitle playback, transport control  362   b  initiates/continues playback and transport control  362   c  provides for per-frame (“step”) viewing, as will be understood by those skilled in the art. Start and end time selectors  363   a  and  363   b  are used respectively for selecting and monitoring video, audio and/or subtitle playback position and for setting and monitoring a playback stop time. 
     Assembled elements panel  306  provides interactive and selectable listings of authored contents of a current movie title, including but not limited to movie volume  361 , movies  362  and menus  363 . 
     Log panel  308  provides selectable progress reports and other information relating to decoding/encoding of presentation data, compiling and layout of a disk file format according to DVD disk format specifications  205  ( FIG. 2 ). These reports are automatically created and can be accessed using log tabs exemplified by tabs  381  and  383 . 
     Preview video panel  303  selectively displays a video frame corresponding to a cursor position over assembly panel chapter portion  350 , video assembly portion  320 , audio assembly portion  330 , subtitle portion  340  and/or chapter portion  350  of assembly panel  302 . In addition, preview video panel is used for previewing video data using transport controls  362   a  through  362   c , start and stop time selectors  363   a  and  363   b  or directly invoking the panel using selection or drag-and-drop capabilities. (As will be understood by those skilled in the art, encoded video and audio files are decoded and buffered, as needed, for playback in a conventional manner using MPEG encoder/decoder  130  of  FIG. 1 .) 
     The following toolbar chart lists the respective elements of toolbar  399 . It will be understood by those skilled in the art, in view of the discussion herein, that the toolbar elements can vary substantially and includes user-defined expandable and replaceable elements. The elements shown are provided as defaults. 
     
       
         
           
               
               
               
             
               
                   
               
               
                 Label 
                 Referenced as 
                 Description 
               
               
                   
               
             
            
               
                 401 
                 New volume 
                 Loads default values and adjusts the 
               
               
                   
                   
                 interface for a new movie title. 
               
               
                 403 
                 New menu 
                 Loads default values and adjusts the 
               
               
                   
                   
                 interface for a new menu layout. 
               
               
                 405 
                 New movie 
                 Loads default values and adjusts the 
               
               
                   
                   
                 interface for authoring a new movie. 
               
               
                 407 
                 Connections 
                 Switches to an existing connections 
               
               
                   
                   
                 interface or adjusts the interface, 
               
               
                   
                   
                 according to default values for initially 
               
               
                   
                   
                 setting connections. 
               
               
                 413-415 
                 Cut, copy and paste 
                 Provide conventional functions except 
               
               
                   
                   
                 as described herein for connections. 
               
               
                 421 
                 Compile start 
                 Initiating compiler operation. 
               
               
                 423 
                 Compiler stop 
                 Interrupts compiler operation. 
               
               
                 425 
                 DVD Layout 
                 Invokes DVD Disk layout operation. 
               
               
                 427 
                 Write Tape 
                 Provides for output of multiplexed 
               
               
                   
                   
                 data stream to tape. 
               
               
                 429 
                 Simulator 
                 Invokes simulator 
               
               
                   
               
            
           
         
       
     
     The  FIG. 5  flowchart illustrates, by way of example and with reference to  FIGS. 3 and 4 , how an interface in accordance with the invention enables an author to assemble performance data and objects without consideration for structures, commands or ordered tasks imposed by DVD programming specifications  207  ( FIG. 2 ). Select, open and drag-and-drop, among other operations, and clicking, double-clicking, click-and-drag and other user actions associated with graphic interfaces are well known and will not be further expounded upon herein. 
     As shown, in step  505 , an author initiates a new project (“volume”) by selecting new volume  401  ( FIG. 4 ). In step  510 , the author initiates a new movie by selecting new movie  405 . In step  515 , the author adds video and audio files to presentation data panel  301  ( FIG. 3 ) for potential use in the volume by movies and menus. In step  520 , the author can preview a video file in preview panel  304  by dragging its icon in presentation data panel  301  to preview panel  304  and/or, if desired, by invoking transport controls  362   a  through  362   c , preview timer  393  and/or other playback-related controls. In step  525 , the author adds a selected video clip to the currently opened movie by double-clicking its icon in presentation data panel  301  or by dragging the icon from presentation data panel  301  to video assembly portion  320  of performance view  303 . In step  530 , the author can select a video frame thumbnail other than a first frame for reference viewing by dragging the pointer of thumbnail timer  325   a  and/or by using transport controls  362   a  through  362   b.    
     In step  535 , the author can preview an audio file by selecting its icon in presentation data panel  301  and using controls including stop  362 , play  362   b , using start time and end time selectors  363   a  and  363   b  and/or using other play-related controls. In step  540 , the author adds a selected audio clip to a next available track of the currently opened movie by double-clicking its icon in presentation data panel  301 . (Alternatively, the author can add a selected audio clip to a specific audio track by dragging the icon from presentation data panel  301  to a selected track in audio assembly portion  330  of performance view  303 . In step  545 , the author selects a language label by selecting selected language indicator  335  and selecting a listed element. 
     In step  550 , the author opens a subtitle frame and enters subtitle information for display in a video frame during playback of video clips. In step  555 , the author selects a language label corresponding to the subtitle track containing the subtitle frame. If, in step  560 , the author elects to add more performance data, then the author returns to step  520 . 
     In step  565 , the author moves a cursor within chapter assembly portion  350  of performance view  303  to view video frames available as chapter points. In step  570 , the author selects a chapter point. If, in step  575 , the author elects to add more chapter points, then the author continues at step  565 . 
     In step  580 , the author selects an audio track number and optionally selects a subtitle track number and/or playback start and/or end times before selecting play button  362   b  to preview playback of the video clip and the audio clip referenced by the selected track number. 
     The  FIGS. 6   a  and  6   b  flowchart (with reference to  FIGS. 2 and 3 ) generally illustrates responses by the preferred authoring program  201  to an author&#39;s actions according to the invention. As shown, if in step  602  an author selects a movie assembled in a prior authoring session, then, in step  604 , data management engine  165  ( FIG. 2 ) loads related parameters and, in step  606 , sends the parameters to authoring engine  160 . Otherwise, default parameters for a new movie are loaded in step  608 . 
     In step  609 , authoring engine  160  updates assembled elements panel  307  ( FIG. 3 ) and other affected interface  160   a  elements to indicate the movie parameters. If, in step  612 , the author selects presentation data files, then data management engine  165  loads and sends the respective presentation data file parameters to authoring engine  160  in step  614 , which updates presentation data panel  301  in step  616 . If, in step  622 , the author assembles one of the selected video clips, then authoring engine  160  accordingly updates video assembly portion  320 , chapter assembly portion  350  and offset clock  352  in step  624 , updates assembled elements panel  307  in step  626 , and sends the video clip parameters to data management engine  165  for storage in step  628 . Similarly, if the author assembles one of the selected audio clips in step  632 , then authoring engine  160  updates the selected track of audio assembly portion  320  in step  634 , updates assembled elements panel  307  in step  636 , and sends the audio clip parameters to data management engine  165  in step  638 . If, in step  642 , the author assembles subtitle data, then authoring engine  165  updates subtitle assembly portion  340  in step  644 , updates assembled elements  307  in step  646 , and sends subtitle data and parameters to data management engine  160  in step  628 . 
     If, in step  652 , the author moves an interface  160   a  pointer (e.g. a mouse pointer) within chapter assembly portion  360 , then in step  654  authoring engine  160  updates wallclock  351 , finds an I-frame (i.e. a video frame that is completely described without reference to other frames) within the video clip corresponding to the mouse pointer position and displays the I-frame in preview video panel  309 . If, in step  672 , the author assembles a chapter point, then authoring engine  160  updates video assembly portion  340  and chapter assembly portion  350  in step  674 , updates assembled elements panel  307  in step  676 , and sends corresponding chapter parameters to data management engine  165  in step  678 . 
     The  FIG. 7  screenshot illustrates the preferred authoring window  300  of  FIG. 3  with the performance data assembly panels replaced by panels for allowing an author to layout menus. More particularly, menu layout panel  701  and menu tools panel  702  are selected, sized and positioned to replace performance view  303  of  FIG. 3 . An exemplary menu layout including graphic and textural images is shown in menu layout panel  701  for purposes of illustration. Menu layout panel  701  is used visually and interactively by an author to retrieve, add, place and modify menu elements using menu tools panel  702  selections. 
     In accordance with the DVD Specification, menu elements presentable to a DVD consumer can include a background image (“background”), an overlay image (“subpicture”) and up to twenty-five buttons. For the present example, author-selected background  710  is a multicolor design, and author-selected subpicture  711  includes the textural information, Dolby Demo 1, Dolby Demo 2, Play Both Demos and Main Menu. Four author-created buttons  720   a  through  720   d  including button frames  721   a  through  721   d  are also shown. Each of button numbers  722   a  through  722   d  is added by authoring program  201  ( FIG. 2 ) in response to creation of a respective button for identification purposes (i.e. during authoring and for use in compilation). 
     Menu tools panel  702  comprises controls for implementing selectable menu element parameters and for selectably altering the display characteristics of elements within menu layout panel  701  during an authoring session. For example, color selection boxes  732 ,  734 ,  736  and  738  allow an author to choose a button outline color for display (in a consumer viewing scenario) when a button is not selected (“normal”), when a consumer points at the button (“selection”) and when a button is invoked (“action”) respectively. An author can also select the opacity of the buttons for these cases using opacity sliders  733 ,  735 , and  737  respectively. Similarly, an author can select button shapes and other characteristics by selecting one of the layout feature tabs  739  and utilizing the tool sets that appear in a respective tool set panel (not shown). An author might, for example, utilize prior button shape, color, texture, opacity and/or normal, selection and activation color combinations used with a prior authoring session as either a starting point for further changes or without further modification. Other parameter combinations might also be utilized. Safe area toggle  755   a  allows an author to selectively display safe area indicator  755   b  of menu layout panel  701  (which bounds an area that is assured to be displayed on a consumer television). Display controls  751  and  752  provide for altering the characteristics indicated which, in light of the prior discussion, will be understood by those skilled in the art without further edification. 
     Layout feature tabs  749  also provide access to button ordering tools (not shown). As with other authoring parameters, an author can selectively utilize an existing order of buttons that will be traversed in a currently displayed menu when a consumer pushes directional buttons on a remote control device. An alternative order can also be set using any number of methods including but not limited to using a displayed remote control device or dragging an arrow from a starting point to an ending point. Such features and their operational characteristics, given the foregoing, will be understood by those skilled in the art without further edification. 
     The  FIG. 8  flowchart shows how the actions required for laying out a menu are consistent with those for assembling performance data. Once again, authoring is visually and interactively achieved without requiring any specific ordering of actions. Therefore, as with performance data assembly, the specific ordering of actions is given for purposes of illustration only. 
     As shown, in step  805 , the author selects background and subpicture files for inclusion in a menu layout. Selected files will appear in presentation data panel  301  ( FIG. 7 ). In step  810 , an author adds a background and a subpicture to the current menu by double-clicking on file listings, dragging the files to menu layout panel  701  or by using a similar method. In step  815 , the author draws (i.e. drags a box) around subpicture text forming a button frame, thereby indicating button placement directly in menu layout panel  701 . If, in step  820 , more button flames remain to be added, then the author returns to step  815 . 
     In step  825 , the author selects a button and sets shape, size, opacity and other parameters using preset combinations and/or color selection boxes  732 ,  734 ,  736  and  738 , opacity sliders  733 ,  735 , and  737  and/or other tools. In step  830 , the author sets the intra-menu button order in the manner already described. If, in step  840 , more menus remain to be created, then the author selects add menu button  413  in step  840 , and returns to step  805 . New elements appear in assembled elements panel  307  and control data (i.e. relating to added elements and their layout characteristics) are sent to data management engine  165  ( FIG. 2 ) as with performance data assembly. 
     The  FIG. 9  screenshot illustrates a further selectable configuration of the  FIG. 3  interface for linking together presentation data, menu layouts, buttons within menu layouts and available control functions of a DVD player. As shown, connection view  901  includes available targets panel  903  and linking panel  905 . Linking panel  905  further includes available sources portion  950  and connected targets portion  960 . While connections view  901  is active, assembled elements panel  307  can further be used as a selection means for navigating more quickly to a desired target within available targets panel  903 . 
     Operationally, an author forms a link or “available connection” simply by copying (i.e. performing a copy action or dragging) a target from available targets portion  903  to a position in connected targets portion  960  that is in the same row as a desired source in available sources view  950 . As with assembling a movie and menu layouts, an author can interactively remove, move or otherwise modify links in a conventional manner. For example, a link can be removed by deletion or a target can be moved or copied to another row in linking portion  905 . 
     As with arranging performance data and forming menu layouts, an author has easy and complete flexibility in adding interactivity to a consumer&#39;s viewing experience. A DVD movie can be authored, for example, such that entry and exit from a menu can be controlled by any available event. Referring also to the  FIG. 10  simulator window  1000 , any menu button can further be linked to any DVD event, including but not limited to a chapter point (e.g. chapter point  953 ), the end of chapter playback or depressing a DVD remote control device menu button  1020  and  1040  ( FIG. 10 ). A particular menu button can also be used as a target in multiple instances, as might be creatively appropriate. 
     Thus, for example, a consumer interface can be quickly and easily created which is interactively responsive (“context sensitive”) to a consumer&#39;s actions. Stated alternatively, an interface can be authored such that, for example, the conclusion of a specific chapter playback or menu button activation will determine a next chapter playback, a next menu or even a next menu wherein an author-selected menu button is highlighted. 
     Among the reasons for such ease and flexibility is that, contrary to conventionally authored DVD movies, program chains are not created during the authoring process. Similarly, connections specified during authoring are not permanent (“hard wired”). Rather, program chains are not created until compilation and available connections are not fully resolved until playback, each according to additional abstractions of the invention, as will be further discussed herein. 
     The  FIG. 11  block diagram illustrates the structure of a preferred data management engine  165  ( FIG. 1 ) according to the invention. As illustrated, data management engine  165  only partially reflects the interface constructs and the structures of the DVD Specification. While reflecting interface abstractions (e.g. a movie, menu and connection based movie-title description) and DVD Specification requirements (e.g. first play jump source), data management engine  165  is further structured as a flexible network of data storage and distribution objects that also reflects other abstractions of the invention. 
     One further abstraction, for example, is a model of a DVD player, a consumer&#39;s controller and the compiled authoring instructions as an actively connection-switched network. Within this network, DVD program chains representative of action-oriented authoring instructions (“routers”), perform switching among available connections in response to DVD-player (i.e. consumer) instructions, thereby re-directing program flow and control. Control-receiving program chains then perform more localized tasks (e.g. such as displaying a menu). Stated alternatively, a router program chain resolves an available connection from a DVD-player control instruction to a receiving program chain, which again routes control or executes the instruction. Further abstractions also include models of program chains for performing a common base functionality in a same or similar manner using a derived common program chain structure. 
     Such an arrangement provides real world flexibility and efficiency. For example, data management engine  165  supports authoring flexibility with regard to source-target connections that are switchable. Further, given the power of even conventional computer systems, data management engine  165  is sufficiently robust to enable the interactive operation of interface  160   a  ( FIG. 2 ) as well as minimal compilation times of compiler  170  (i.e. only milliseconds) without direct interface or DVD program specification  205  correlation. Data management engine  165  is therefore also readily adaptable to interface variations and further interfaces, as well as to compiler variations and other compilers supporting other DVD and non-DVD data storage and/or retrieval applications. 
     Referring again to  FIG. 11  and with further reference to  FIG. 2 , data management engine  165  comprises a root volume object  1100 , which manages data management engine  165  communication and storage. Volume object  1100  provides an interface for communicating messaged data to and from its component parts, including title key jump source  1101 , first play jump source  1102 , media database  1103 , DVD layout properties  1104 , movies list  1105 , menus list  1106  and connections list  1107  (objects). Media database  1103  further includes media files list  1130 , which stores pointers to media files referred to by the performance data arrangement as a result of authoring. 
     In addition, each of the presentation data objects (i.e. movies list  1105  and menus list  1106 ) and a connection sets list object  1107  contain links to other data management engine objects in the form of an object tree. More specifically, movies list  1105  is linked to movie objects movie- 1   1150   a  through movie-M  1150   b , wherein M is the total number of movies authored for storage on a single DVD-ROM (“movie title”). Each movie object contains a respective track list object  1151  and a respective chapter list object  1152 . Each track list object  1151  contains respective track objects, track- 1   1153   a  through track-T  1153   b , wherein T is the total number of tracks authored within a respective movie. Track- 1  through track-T further contain clip lists, which in turn contain clip objects clip- 1   1154   a  through clip-CL  1154   b  (and wherein CL is the total number of clips in a given track within a given movie). Finally, each clip object contains a respective clip properties object, as exemplified by clip object  1155 . 
     Menu objects are structured in a manner similar to that of movie objects. Menus list object  1160  contains menu objects menu- 1   1160   a  through menu-N, wherein N is the total number of menus authored for storage on a given DVD-ROM. Each menu object further contains a respective button list object (e.g. object  1161 ), each button list object contains a respective button objects (button- 1   1162   a  through button-B  1162   b ) and each button object is linked to a button properties object (e.g. object  1163 ). B indicates a total number of buttons in a respective menu. 
     Finally, connections sets list  1107  contains respective connections lists (i.e. connect-list- 11170   a  through connect-list-CL  1170   b ), wherein CL is the total number of connections lists authored for storage on a given DVD-ROM. Each connect-list is further linked to respective connections objects (i.e. connect- 1   1171   a  through connect-CN), wherein CN is the total number of connections authored to facilitate flexible program flow and control. Each connections object ( 1171   a  through  1171   b ) represents an action-oriented switch between a respective source and a respective target (as indicated by source-pointer variable  1172  and target-pointer variable  1173 ), as will be discussed further herein. 
     Where applicable, each object includes an indexed object list having a pointer to each connected dependent object (i.e. an object “further down the tree” as illustrated), as well as a totals variable. The object list is updated to include new dependent objects as these objects are created (“instantiated”) to reflect, for example, an added chapter point or menu. Dependent objects are similarly removed from the object list according to authoring deletions. Totals variables are also updated during authoring to reflect each corresponding dependent object instantiation and deletion. Undo and redo operations are handled in a conventional manner using authoring instructions which are further conventionally stored within respective objects during each authoring session. 
     Using this structure, data management engine  165  breaks down or filters control data generated during authoring into its basic component parts for storage in a corresponding object&#39;s indexed data list. These basic component parts are then retrieved by authoring engine  160 , or retrieved and reconstructed into an applicable form by compiler  170 , as needed. 
     Operationally, data management engine  165  receives messages from authoring engine  160  in response to and reflecting each author modification of a performance assembly, menu layout or connection. Volume  1100  receives the message, polls its contained-objects list for a recipient object according to the message type, and sends the message to the matching recipient object. If the message includes a reference to a title key source or a first play source (which is author-selectable in connections view  901 ), then volume  1100  sends the message respectively to either title key jump source  1101  or first play jump source  1102 . Upon receipt, title key jump source  1101  or first play jump source  1102  will accordingly store included data, delete stored data or modify stored data. 
     If a received message includes a reference to a video, audio or subtitle file, then volume  1100  sends the message to media database  1103 . If the message contains an instruction to add a data element, then media database  1103  stores the data (which will include a pointer to a media file) in media files list  1130 . If the message contains an instruction to delete a stored pointer, then media database  1103  deletes the pointer. If the message contains an instruction to modify a stored pointer (e.g. if the file was moved to a new location), then media database  1103  locates and replaces the file pointer. Media database  1103  further updates its totals variable to reflect additions and deletions. 
     If a received message type relates to the content of a movie arrangement, menu layout or connection, then volume  1103  sends the message respectively to movies list  1105 , menus list  1106  or connections list  1107 . Each of movies list  1105 , menus list  1106  and connection sets list  1107  operates similarly to objects described thus far. Each parses through a received message for included control information, sends the message respectively to a corresponding movie object, menu object or connections list and adjusts its totals variable as needed. 
     A movie message, for example, will then progress down through the movie object tree, and, depending upon the message type, will be filtered, by track list  1152  track- 1   1153   a  and then handled a matching clip, or will be filtered by chapter list  1152  and then handled by corresponding chapter or by a clip properties object (i.e. as illustrated). Menu layout data will similarly progress (as illustrated) down through the menus list tree, being handled by a matching menu properties object, and connections data will progress down the connection sets list tree until it is handled by a connection object (with reference to its source pointer or destination pointer variables). Upon receipt, a clip properties, menu key, end key, menu properties or connection object will handle the message and store included data, delete stored data or modify stored data in a similar manner as with media database object  1103 . 
     Each respective storage object stores authoring modifications in a sequentially indexed list according to its type (i.e. each object name is illustrated to reflect the data type the object stores). Thus, for example, chapter points within a movie are stored from a first chapter point during playback to a final chapter point in the movie. (Playback will however, be determined by authored connections.) The list accommodates added, inserted or deleted data interactively by expanding or contracting about the addition, insertion or deletion point. 
     While other data structures might be utilized, interactively adjusted indexed lists and limited object definitions, using even a minimally equipped computer, are sufficiently robust to accommodate an author&#39;s input rate, given the relatively small amount of data stored in each list. Alternative structures that might be used, for example, include but are not limited to a lesser number of objects each containing a less restricted dataset and/or the addition of summary objects for storing total numbers of menus, buttons and system other status and/or statistical information. Such arrangements however, have been found to add complexity with only moderate gains in application-specific operational characteristics. Alternative data structures, including but not limited to multi-dimensional arrays, multiple queues and linked lists stored locally and/or remotely, present similar tradeoffs. 
     Data management engine  165  returns stored data to authoring engine  160  in a manner essentially the reverse of that for storing data. Volume  1100 , upon receipt of a request for stored data, parses the request call for a data type, searches its contained objects list for a corresponding object, and forwards the request to title key jump source  1101 , first play jump source  1102 , media database  1103 , DVD layout properties list  1105 , movies list  1106 , menus list  1107  or connection sets list  1107 . Movies list  1105 , menus list  1106  or connection sets list  1107 , upon receipt of such a request, parses its available objects list and forwards the message correspondingly to a movie object, menu object or connection list object, and so on, until the message is received by a last recipient object. The last recipient object then retrieves the requested data and sends the data in the reverse direction of request receipt until the data reaches volume  1100 . Volume  1100 , upon receipt of the data, sends the requested data to authoring engine  160 . (Error handling and messaging functionality are otherwise handled in a conventional manner.) 
     Data management engine  165  further responds to queries from authoring engine  160  for purposes such as totaling the number of data elements of a given type or for reviewing the contents of a particular object&#39;s data list. As with data storage and retrieval above, data management engine  165  receives a call from authoring engine  160  requesting information. Volume  1100  parses the message, polls its available objects list and sends the message to a corresponding object. For objects linked to a tree-structure, such as movies list  1105 , menus list  1106  and connection sets list  1107 , the message is forwarded down through respective objects as already discussed, and a last recipient object will respond. If the message requests, for example, a total number of data elements of a given type, then a last recipient will either poll its totals variable or, if necessary, poll its data list for corresponding data, count the number of corresponding occurrences and return a response including the total. The response is sent back through the tree structure to volume  1100 , which sends the message (including the total) to authoring engine  160 . Given the relatively small number of objects, alternatives (such as asynchronous multiple-messaging and, in particular, broadcast messages) add some expediency, but with unnecessarily added complexity. 
     As with the authoring engine interface objects, the object types, inter-object messaging protocol and data objects utilized in data management engine  165 , in view of the disclosure herein, will be apparent to those skilled in the computer arts. Preferably, available object libraries from Microsoft® are utilized. For example, the preferred available objects and data lists utilize Standard Template Libraries and, in particular, Expandable Indexed Buffered/Vectored Lists. Such objects provide robust response with the flexibility of expandable lists and indexed vectors for easy lookup in light of the typically small number of objects and datasets, among other factors. As noted earlier however, use of an object-oriented architecture and/or the specific data structures are not essential and many conventional alternatives can be utilized. 
     As discussed, the particular arrangement of objects of the preferred data management engine  165  is preferred according to its flexibility, performance and adaptability among other factors. It should be noted therefore, that any number of modifications will be apparent according to the teachings and within the spirit and scope of the invention. 
       FIGS. 12   a  through  15 , with reference to  FIGS. 2 and 11 , illustrate compilation according to a preferred embodiment of the invention. 
     As shown generally in  FIG. 12   a , compiler  170  ( FIG. 2 ) preferably operates on data entered through the authoring process into the interface  160   a  of authoring engine  160  ( FIG. 2 ) and stored by data management engine  165  in three stages. In step  1201 , compiler  170  builds an intermediate skeleton-form PGC layout data structure. The skeleton-form PGC layout data structure is preferably formed according to DVD program code segment (“program chain” or “PGC”) abstractions and a network abstraction according to the invention, utilizing only summary data gathered from data management engine  165 . Broadly stated, each PGC abstraction is preferably comprised of pre-determined command combinations, wherein the number of PGCs of a given type and the number of command combinations of a given type (e.g. button command combinations) are determined according to either a default value (e.g. typically one PGC) or according to the number of corresponding authored element types. (e.g. the number of menu buttons in a given menu). 
     In step  1203 , compiler  170  resolves source-target connections as indices to source and target identifier information within data management engine  165 . In step  1205 , compiler  170  replaces the indices with identifier information which is retrieved by further querying data management engine  165 . 
       FIG. 13  illustrates a preferred PGC layout structure according to the invention. As shown, the PGC layout structure is divided into a single first play PGC space  1301  (in accordance with the DVD Specification), a single video manager (“VMGM”) domain  1302 , and one or more video title set (“VTS”) domains (e.g.  1303  and  1304 ) according to the number of movies in the movie title. 
     The preferred VMGM domain PGC layout structure includes a single title key PGC abstraction,  1321  and a single movie router PGC abstraction  1322 . Thereafter, the VMGM PGC structure includes 2 menu PGC abstractions (e.g.  1323   a  and  1323   b ) for each authored menu and a single PGC abstraction for each end command (in each movie) that an author for which an author has specified a connection. As will be discussed further, each menu PGC abstraction pair includes a menu display PGC (e.g.  1323   a  and  1324   a ) and a menu button router PGC (e.g.  1323   b  and  1324   b ). 
     Each VTS domain PGC layout structure (e.g.  1303 ) includes a movie display PGC  1331  and a video title set menu (“VTSM”) area  1332 . VTSM area further consists of from one to four remote key router PGCs (e.g. remote key router PGCs  1332 ), depending upon the number of different remote key commands necessary, given the preferred layout structure, to realize the chapter target connections selected using connection view  901 . More specifically:
 
number of remote key router PGCs in a given VTSM=total number of chapter points in a corresponding movie/25 (rounded, if a non-integer, to a next higher integer value).
 
     In each case, an attempt has been made to minimize the number of PGCs without detrimental impact on flexibility. Thus, while the number of PGCs is as indicated above, complete authoring flexibility with regard to connecting menus, menu buttons and presentation data without concern for limitations of the DVD programming specification  207  ( FIG. 2 ) is provided. Further, the practical impact of resultant limitations is also minimized. 
     For example, the number of remote key router PGCs per VTSM area calculation reflects that each chapter point abstraction requires more than four commands. This in turn reflects that only one hundred twenty eight commands are allowable in a single PGC chain in accordance with the DVD programming specification  207 . While not essential, placing each abstraction completely within a separated chains and in equal numbers throughout like chains provides an efficiently symmetrical structure. Since DVD programming specifications  207  provide for up to ninety nine chapter points per movie, a maximum of four PGC abstractions is required without detrimental impact in terms of connectability. Considering the same parameters and calculations for menus however, it is seen that only twenty five menu buttons are available per menu without limitation on connectability. In practical terms however (i.e. displaying a menu on a conventional television set), this number does not present any practical detrimental effect. 
     The use of consecutive locations in the PGC layout structure greatly simplifies the task of finding specific PGCs relating to specific data types and further for resolving PGC connections. A movie title PGC will always be the first element, a movie router PGC will always be the second element, and a display menu PGC can always be located merely by adding a known constant plus two times the menu number, etc. 
     Those skilled in the art will appreciate however, in view of the discussion herein, that the PGC abstractions provide for other than consecutively arranged elements as an indexed list in memory  120  ( FIG. 1 ). Such alternatives, for example, include but are not limited to multiple lists, queues and/or multi-dimensional arrays stored in memory, in other media, and/or in more than one media either locally or in a distributed fashion, as with data management engine  165 . Such methods can be useful where more than one authoring location or other distributed environments are utilized. 
     The  FIG. 12   b  flowchart, with reference to  FIG. 13 , shows in greater detail how compiler  170  constructs a preferred PGC layout data structure in an initial skeleton form. As shown, compiler  170  begins by storing a first play PGC abstraction, a title key PGC abstraction and a menu router PGC abstraction into PGC layout structure  1300  ( FIG. 13 ) in steps  1207 ,  1208  and  1209  respectively. Next, in step  1213 , compiler  170  queries data management engine  165  for a total number, MenusTot, of menus authored and, in step  1214 , initializes a menu pointer, MenuPtr. In step  1215 , compiler  170  queries data management engine  165  for a total number, ButtonsTot, of buttons authored in a current menu (e.g. initially, a first menu). MenusTot will specify the number of pre-determined menu display and menu button router PGC abstractions (i.e. “menu PGC abstraction pairs”) that compiler  170  will add to the structure, while ButtonsTot will specify the number of commands that compiler  170  will add to each PGC of a current menu PGC abstraction pair. 
     In step  1216 , compiler  170  adds a menu PGC abstraction pair to VMGM PGC structure  1302  ( FIG. 13 ) corresponding to the existence of and the number of buttons in a current authored menu (e.g. initially, a first menu). If, in step  1217 , one or more menus are not yet added to VMGM PGC structure  1301 , then in step  1218 , compiler  170  increments the menu counter and returns to step  1211 . 
     At this point, compiler  170  lacks any authoring information other than MenusTot and a respective ButtonsTot value for each current menu. A similar same lack of further authoring details will also exist for other PGCs in the skeleton-form, PGC layout structure. The preferred PGC and network abstractions of the invention however, enable compiler  170  to accommodate missing authoring details merely by inserting null values (“no-ops”) into the commands of the abstracted PGCs for unknown connection information (i.e. source-target identification information). As discussed, compiler  170  will preferably resolve these no-ops later in compilation. These abstractions further enable menu PGCs to be created independently of movies and movie arrangements. Thus, independently created/conceived menu PGCs provide extensive flexibility, allowing an author to link any available menu button of any menu to any potential target using a user-friendly interface such as the preferred connection view  901 . 
     If instead, in step  1217 , all authored menu layouts are reflected by corresponding menu PGC abstraction pairs, then compiler  170  proceeds to step  1219 . In step  1219 , compiler  170  queries data management engine  165  for the total number, MovieTot, of movies, which compiler  170  will use to create end commands, VTSs and VTS contents. In step  1221 , compiler  170  initializes a current movie pointer (“MoviePtr”), as well as two counters, “EndTot” and “Remote”. Compiler  170  will use EndTot to count the number of available end-of-chapter conditions in each movie for which an author has specified connections and will use Remote to count the number of available playback interruption conditions (i.e. by a user pressing a DVD-player control, typically on a remote control device) for which an author has specified connections. 
     In step  1223 , compiler  170  queries data management engine  165  for the total number of chapters (“ChapterTot”) in a current movie (e.g. initially, the first movie) and, in step  1225 , initializes a current chapter pointer (“ChapterPtr”). If, in step  1227 , the author has specified a target for the current chapter, end-of-chapter condition (i.e. using connection view  901 ), then, in step  1229 , compiler  170  increments EndTot; otherwise, compiler  170  proceeds to step  1231 . Similarly, if, in step  1231 , the author has specified a target for the current chapter, remote-control key playback interruption (“remote-key”) condition, then, in step  1233 , compiler increments Remote; otherwise, compiler  170  proceeds to step  1235 . 
     The existence of authored connections is determined similarly for both end-of-chapter and remote-key conditions. Preferably, objects  1101 - 1163  ( FIG. 11 ) contain actual source and target identifier information (i.e. corresponding to authored sources and targets), while the connection objects (e.g.  1171   a ) contain pointers to data stored by these objects. Stated alternatively, as a new potential source is authored, a connection object is instantiated, including a source pointer that points to the potential source and a null-value target pointer; if an author later connects such a source, then the corresponding connection-object target pointer value is replaced by a pointer to the target object. (Subsequent editing by an author correspondingly deletes or instantiates a connection object and/or changes a source pointer or target pointer value.) 
     Therefore, compiler  170  determines the existence of a connected end command by first querying each connection object for a source pointer pointing to the currently selected chapter-object. Once found, compiler  170  checks the corresponding target pointer. A null-value target pointer indicates an unconnected end command while a non-null-value target pointer indicates the existence of a connection. Remote key (i.e. “menu key” in  FIG. 11 ) connections are similarly determined by finding an identifier in a current chapter menu key object (e.g.  1157 ), finding the corresponding source pointer in one of the connection objects, and then querying the connection object for the existence of a corresponding non-null-value target pointer. 
     Those skilled in the art, in view of the foregoing, will appreciate that considerable variation of the above structure will provide the same, related or similar functionality. For example, identifiers, labels and even complete movie tree, menu tree and/or other objects could well be contained within or duplicated within the connections-tree (i.e. objects  1107 - 1173 ). A single connection object could also be used (i.e. having a single list of all connections), as could connection objects that remain despite the deletion of a source. Other variations are also anticipated. The current structure is however, preferred in that it provides a compilation time of only a few milliseconds, minimizes memory usage and further facilitates debugging, emulation, simulation and overall symmetry by separating these objects (and their contained data). In simulation, for example, the restrictions imposed by the DVD Specification are not controlling and simulation can therefore more efficiently utilize authoring data directly from the preferred, non-integrated data management engine  165  object structure. 
     Returning now to  FIG. 12   b , if, in step  1235 , more chapters remain in the current movie, then compiler  170  increments ChapterPtr and returns to step  1227 ; otherwise, compiler  170  proceeds to step  1237 . In step  1237 , compiler  170  adds a 14 PGC, end command router PGC abstraction to layout structure  1300  ( FIG. 13 ). In step  1238 , compiler  170  creates a VTS domain for the current movie (i.e. including a VTSM), adding to the VTS domain a movie display PGC in step  1239  and adding a 1-4 PGC, remote key PGC abstraction in step  1240 . 
     If, in step  1241 , more movies remain in the current movie title (i.e. tested by comparing MovieTot with MoviePtr), then compiler increments moviePtr in step  1243 , re-initializes EndTot and Remote in step  1245  and returns to step  1223 . Otherwise, formation of a PGC layout structure in skeleton form has been completed. 
     The  FIG. 12   c  flowchart with reference to  FIG. 11  shows how compiler  170  replaces the no-ops in (skeleton form) PGC layout structure  1300  with indices (i.e. source or target pointers) to respective sources and targets, and then further replaces the indices with element identifiers. In step  1251 , compiler  170  initializes a movie pointer (“MoviePtr”) to a first movie, a chapter pointer (“ChapterPtr”) to a first chapter, a menu pointer (“MenuPtr”) to a first menu and a button pointer (“ButtonPtr”) to a first button. 
     In step  1253 , compiler  170  queries data management engine  165  (i.e. connection-objects) for a source-pointer to a next (initially, a first) author-connected button. As discussed earlier, the connection object checks its source-pointer for a corresponding source having a corresponding non-null-value target pointer. Since specific connection values (rather than the existence of a connection as with  FIG. 12   b ) are required in this case, the query utilized results in the return of such a source-pointer. In step  1255 , compiler  170  uses the returned source-pointer to query data management engine  165  for the corresponding target-pointer and, in step  1257 , compiler  170  uses the returned indices to query data management engine  165  (e.g. via volume  1100 , menu- 1   1160   a  and button list  1161  to button- 1   1162   a ) for the source and target identifiers corresponding to the source and target pointers. Then, in step  1259 , compiler  170  replaces the current button command no-ops (of the current menu PGC abstraction pair) with the returned identifiers. 
     If, in step  1261 , more buttons remain unresolved in the current menu, then compiler  170  increments ButtonPtr in step  1263  and returns to step  1253 ; otherwise, compiler  170  proceeds to step  1265 . If, in step  1265 , menus remain unresolved, then compiler  170  increments MenuPtr and resets ButtonPtr to one in step  1267 , and then returns to step  1253 ; otherwise, compiler  170  proceeds to step  1271 . 
     Having resolved and replaced all menu button no-ops, compiler  170  next resolves all chapter end-command and remote-key PGC abstraction no-ops in a similar manner. Compiler  170  queries data management engine  165  for a (next connected) current chapter end command source-pointer in step  1271 , uses the returned source-pointer to query data management engine  165  for a corresponding target-pointer in step  1272 , uses the pointers to query data management engine  165  for corresponding identifiers in step  1273  and replaces corresponding layout structure  1300  PGC commands with the returned identifiers in step  1274 . Similarly, compiler  170  queries data management engine  165  for a (next connected) current remote key source-pointer in step  1277 , uses the returned source-pointer to query data management engine  165  for a corresponding target-pointer in step  1278 , uses the pointers to query data management engine  165  for corresponding identifiers in step  1279  and replaces corresponding layout structure  1300  PGC commands with the returned identifiers in step  1280 . 
     If, in step  1283 , more chapters remain unresolved, then compiler  170  increments the chapter pointer in step  1285  and returns to step  1271 . If instead, no chapters remain unresolved in the current movie, then compiler  170  proceeds to step  1286 . In step  1286 , compiler  170  queries data management engine  165  (i.e. via volume  1100  to media database  1103  of  FIG. 11 ) for all audio and video file references which reference the current movie. In step  1287 , compiler  170  invokes multiplexer  185 , which retrieves the referenced audio and video files and outputs a resultant multiplexed data file in a conventional manner and in accordance with the DVD disk format specifications  205  ( FIG. 2 ) of the DVD Specification. 
     If, in step  1288  more movies remain unresolved in layout structure  1300 , then compiler  170  resets pointers for the next movie and first chapter in step  1289  and returns to step  1271 . Otherwise, compiler  170  (in a similar manner) resolves first play, title key jump source and menu router no-ops respectively in steps  1291 ,  1293  and  1295 . Then, in step  1297 , compiler  170  saves the PGC layout structure as a stored file. 
     With regard to  FIGS. 12   b  and  12   c , total authored element values (i.e. such as MenusTot and ButtonsTot) are maintained on an ongoing basis in a corresponding list object or the functional equivalent of a list object as already discussed. For example, movies-list object  1105  ( FIG. 11 ), in addition to a list for containing references to all instantiated movie objects, also contains a variable for updating the total number of movies in a current movie title during the course of one or more authoring sessions. Similarly, button-list object  1161  contains a list of instantiated button objects (e.g.  1162   a  through  1162   b ) as well as a variable indicating the total number of buttons in menu- 1 . Other list objects similarly include ongoing totals which are updated during the course of authoring. One reason is that some early-generation DVD-players limit the available memory space for storing PGCs, which correspondingly limits the number of elements (e.g. menus, menu buttons and chapters) that the invention permits to be authored. These limits and/or current totals are therefore selectively conveyed to an author through interface  160   a . Ongoing totals are also beneficial in that no time periods are required during compilation for calculating such totals. 
     As will be understood by those skilled in the art however, total values might become unimportant for other than compilation purposes as DVD-players are manufactured with increasing resources in conformance with the current DVD Specification, in accordance with expanded DVD capabilities and in accordance with the requirements of non-DVD systems. In such cases, totals can alternatively be calculated during compilation. 
     The use of preferably pre-determined PGC abstraction types comprising preferably pre-determined command combinations and the preferred PGC layout structure are thus factors in providing a maximized authoring flexibility and efficient compilation among other benefits. Available connections remain completely flexible during authoring and, in fact, until substitutions are made for no-ops during compilation. The preferred structures of PGC abstractions further add to compilation efficiency, since a skeleton can be formed with only summary authoring data, and then authoring details can be quickly added thereafter. 
       FIGS. 14 and 15 , with reference to  FIG. 13 , illustrate a preferred network or “connection-switching” abstraction according to the invention. The connection-switching abstraction, while operationally active only during playback of a movie-title, is also a factor in determining PGC abstractions produced by compiler  170  as well as the movie, menu and connection movie-title abstraction utilized by data management engine  165 , interface  160   a  and authoring engine  160  ( FIG. 2 ). 
     Details of the DVD Specification including but not limited to multiplexed data stream and DVD player configurations, data formats, protocols and loading of data are known to those skilled in the art and will therefore be discussed only to the extent required for an understanding of the invention. 
     DVD programming specifications  207  ( FIG. 2 ) provide that PGCs can reside (along with the corresponding presentation data) in virtual structures including a first play space, a video manager (“VMGM”) and any of 99 video title sets (“VTSs”), each of which includes a video title set menu space (“VTSM”). Among the limitations of this virtual structure however, is first that a PGC in an initial VTS or VTSM cannot directly trigger (i.e. jump to, using a DVD jump command) a PGC stored in another VTS (or VTSM). For example, while a PGC in an initial VTS can “playback a chapter of presentation data” and the conclusion of chapter playback can trigger a “followup” PGC, the followup PGC cannot be stored in a different VTS. Similarly, an initial PGC used to respond to DVD consumer menu-button activation cannot trigger a second PGC which is is stored in a different VTS. A further relevant limitation is that the format of performance data must remain constant within a given VTS. So, for example, a video data stream having one aspect ratio cannot be stored in the same VTS with another video data stream having a different aspect ratio. 
     The  FIG. 14  functional diagram illustrates how the preferred connection-switching abstraction provides a flexible and robust functional superstructure within which movie-title, DVD-player and interactively occurring consumer-control events are routed and executed. In the figure, VTS-A  1303  and VTS-A+1 exemplify any two different VTSs which have been created during compilation of a movie-title. It should also be noted that the illustrated connection arrows only denote the “path” from one box (i.e. PGC abstraction, PGC or command-set) to another that can result from an author&#39;s use of connection view  901  ( FIG. 9 ). Thus, fewer connections than those illustrated might be authored and each path from one box to another is accomplished individually using a single “jump command” or a single transfer of control by a DVD-player. (The use of multiple connected arrows and shared arrows is used only for clarity sake, since the alternative use of individual arrows between each pair of boxes might otherwise obscure the invention.) 
     Within each VTS, only a movie display PGC abstraction operates as a “control PGC” (i.e. directly controls menu and/or movie display). For example, VTS-A  1303  includes movie display PGC abstraction  1331  and (within its VTSM domain  1322 ) remote key PGC abstraction  1322   a  Movie display PGC abstraction  1331  comprises a single PGC which includes a command-set (“precommand”) for selecting a chapter and initiating playback of the chapter, as well as an end command “cell command” that initiates routing upon the occurrence of an end-of-chapter-playback condition. Remote menu key  1431   a , which denotes an automatic DVD player function, traps and forwards a remote-key condition (i.e. user depression of a remote menu key which interrupts playback). Remote menu key router PGC abstraction  1322   a  of VTSM-A  1322  sets the authored target for a corresponding remote menu key condition (i.e. where a consumer presses a remote menu key during playback) and then routes control to a corresponding movie PGC abstraction or menu PGC abstraction within VMGM  1302 . Other VTSs (e.g. VTS-A+1  1304 ) are similarly structured for each movie within the current DVD movie-title. 
     Each remote menu key router PGC abstraction includes up to 4 PGCs to accommodate the up to 99 chapter points per movie limitation of the DVD Specification. The first remote menu key PGC is always assigned as a root menu and is always a hardwired (i.e. unalterable) target for any remote menu key condition (in accordance with the DVD Specification). Therefore, in order to provide for chapter dependent routing of a remote menu key condition, a DVD-player system register must first be queried for the last played chapter. Using the returned last played chapter information, program execution is then diverted to the corresponding authored remote menu key router PGC. 
     VTSM  1302  comprises the discussed menu display PGC (e.g.  1322 ) and menu button router PGC (e.g.  1323   b ) abstraction pairs (for providing menu control), as well as the remaining router PGC abstractions. More specifically, movie router PGC abstraction  1322  acts as a playback bridge between VTS domains, receiving control from a remote key PGC in a first VTS (e.g. remote key PGC  1322   a  of VTS  1303 ) and then forwarding control to a movie display PGC abstraction in second VTS (e.g. movie play PGC  1341  of VTS  1304 ). In contrast, end router PGC abstractions (e.g.  1325  and  1326 ) can be author-connected to route control from an end-of-chapter condition to either a selected chapter in a selected movie, or to a selected menu button in a selected menu. 
     As shown, a separate PGC is provided for each author-connected end-of-chapter condition. Each end command router PGC abstraction is paired with (i.e. responds to) a specific end command such that each end-of-chapter condition for a given movie will be routed from the end command to a unique end router PGC abstraction. Separate end command PGCs are required due to a flaw in current generation DVD-players whereby the last played chapter is not reliably available at the end of chapter playback. Upon correction of this flaw in future generation DVD-players however, end command routing can be accomplished in a manner consistent with remote menu key PGC abstractions (i.e. using only up to four end-command router PGCs per movie). 
     A menu display PGC abstraction (e.g.  1323   a ), when it receives control as a target and thereafter while a consumer continues to depress menu navigation buttons, effectuates control by highlighting a menu button and displaying the menu. If however, a consumer activates a menu button, then the DVD-player initiates the corresponding router PGC abstraction (e.g.  1323   b ), which routes control (i.e. according to an authored connection) to either a movie display PGC or to a menu display PGC. 
     For clarity sake, the first play PGC abstraction  1301  and title key PGC abstraction  1321  ( FIG. 13 ) are not shown in  FIG. 14 . Each operates to transfer control to either a menu display PGC or a movie display PGC as with the end command router PGCs and menu router PGCs. First play PGC  1301  is stored in a separate DVD-player storage location, while title key PGC  1321  is stored in VMGM  1302 . 
     While those skilled in the art will appreciate, in view of the discussion herein, that considerable variation might be utilized, iterative experimentation with different connection-switching abstractions and DVD players has revealed a number of considerations. For example, command execution delays will necessarily occur as a result of PGC execution and greater delays typically result from transfer of control between a VTS (e.g.  1303  and  1304 ) and VMGM  1302 . Another example is that a delay occurring prior to the start of a movie is observed to be more acceptable than a similar delay during navigation through what can be a large number of menus. A still further example is that consistent delay periods for similar transitions is more acceptable than inconsistent delays for similar transitions. 
     Thus, the preferred connection-switching abstraction provides a generally symmetrical structure wherein delays are first minimized by source-router-target execution paths having a minimum number of PGCs and PGC commands. Movie display PGC abstractions are further placed similarly within each VTS, while menu PGC abstraction pairs are placed similarly within VMGM  1302 . (Note that an author typically only connects the end command of a last chapter within any given movie, such that the DVD-player will continuously play all chapters with the movie before control is routed outside the corresponding VTS). In addition, movie router  1322  is only used for VTS-to-VTS transitions This reflects, for example, that inconsistent delay between movie-to-movie playback and menu-to-movie playback is more acceptable than imposing further delay on menu-to-movie playback or other alternatives. (For example, further distribution and/or re-distribution of movie and/or menu routing functions have been observed to produce subjectively less acceptable results.) In addition, movie router  1322  complexity and PGC length is therefore reduced. It should be understood however, that these already short delay periods will further decrease as advances are made in DVD-player technology and that the resulting decreasing importance of such considerations might well contribute to further connection-switching abstraction variations. 
     The  FIG. 15  flowchart broadly illustrates the operation of preferred connection-switching abstraction  1400 . In step  1503 , first play PGC abstraction is invoked in response to insertion of a movie-title into a DVD-player. The first play PGC abstraction (i.e. now the current PGC abstraction) determines target information (i.e. a target identifier and, if needed, target parameters). If, in step  1505 , a router is required, then, the current PGC abstraction routes the target information and control to a next router abstraction in step  1507  and operation returns to step  1511 . If no router is required in step  1505 , then, in step  1509 , the current PGC abstraction routes the target information to the target PGC abstraction. 
     If, in step  1511 , the target is not a chapter (i.e. playback of a chapter is not the resultant authored event) then the target displays a menu (i.e. according to the target information) in step  1513  and the DVD-player waits for a menu button to be selected (i.e. step  1513  through  1515  act as a wait loop). If, in step  1515  a menu button is selected, then the current PGC abstraction sets authored target information for the selected button in step  1517  and operation returns to step  1505 . 
     If instead, in step  1511 , the target is a chapter, then the target initiates playback of the chapter. If further, in step  1525 , a consumer invokes the remote menu key during playback of the chapter, then the current PGC abstraction sets authored target information in step  1527  and operation returns to step  1505 . If, in step  1525 , the remote menu key is not invoked (i.e. the chapter plays uninterrupted to its conclusion) and a chapter end command target has been authored, then the current PGC abstraction sets the authored target information in step  1537  and operation returns to step  1505 . If, in step  1535 , a chapter end command target has not been authored, then operation continues in step  1545 . 
     If, in step  1545 , more chapters exist in the current movie, then the DVD player increments the chapter number in step  1543  and operation returns to step  1523 . If instead, in step  1545 , no more chapters remain unplayed in the current movie, then the player suspends playback and (in some models) switches itself off. 
     For clarity sake, the operation of preferred connection-switching abstraction  1400  will also be discussed, by way of example, with reference to  FIG. 14 . If, for example, an authored-connection for first play is set to begin playback of a first chapter of a first movie stored in VTS-A  1303 , then upon insertion of the DVD movie-title into a DVD-player, movie display PGC abstraction  1331  will be invoked. Movie display PGC  1331  will select and initiate playback of the first chapter. 
     If the first chapter playback is interrupted by a remote menu key condition, then the DVD-player will automatically trap the condition (i.e. box  1431   a ) and will initiate the root menu PGC of remote menu key router  1322   a  of VTSM-A  1322 . Assuming further that less than 25 chapters exist in the first movie, the root menu PGC of remote menu key router  1322   a  (i.e. now the current source PGC abstraction) will set the author-selected target for the first chapter remote menu key condition and will route control to either movie router  1322  or a menu display PGC (e.g.  1323  or  1324 ) within VMGM  1302 . If movie router  1322  receives control, then upon receipt, movie router further routes control to the author-connected movie display PGC, in this case, movie display PGC  1341  of VTS-A+1  1304 , which will set and initiates playback of the author-selected chapter of the VTS-A+1 movie. 
     If instead, playback of the first movie is not interrupted and only the last chapter of the first movie includes an author-connected end command, then the DVD-player will continue to play successive chapters of the first movie until the conclusion of the last movie. At the conclusion of the last movie, the DVD-player will execute cell command  1431   b  (i.e. end command), which will transfer control to the PGC in end router  1325  (in VTSM  1302 ) that corresponds with the chapter last chapter played. i.e. the last chapter of VTS-A movie. (Since, in this case, only one chapter in the VTS-A movie has a connected end-of-chapter playback condition, end router  1325  will include only the one corresponding PGC.) 
     Upon receipt of control from end command  1431 , end router  1325  (i.e. now the current source) will set the corresponding author-connected target included in end router  1325 . Assuming the target is the VTS-A+1 movie, end router  1325  will further route control to movie display PGC  1341  of VTS-A+1  1304 , which will set and initiate playback according to the chapter of the VTS-A+1 movie set by end router  1325 . (Since control is not being routed from one VTS to another VTS, movie router  1322  is not utilized.) 
     If instead, the current source PGC of end router  1325  (i.e. again, the only PGC in end router  1325  in this example) includes an author-selected connection to menu N  1323 , then end router  1325  will set target parameters and will route control to menu display PGC  1323   a . Menu display PGC  1323   a  will highlight the button of menu-N  1323  according to the received target parameters and will then display menu-N  1323 . Menu display PGC  1323   a  will thereafter continue to be invoked by the DVD-player and will continue to highlight a button and display menu-N  1323  correspondingly with each successive uninterrupted (i.e. by consumer selection of a conflicting DVD control function) consumer depression of a navigation button. If however, the consumer next activates a displayed menu button, then the DVD-player will invoke menu button router PGC  1323   b . Once invoked, menu button router PGC  1323   b  will set target parameters according to the author-selected connection for the activated button, and so on. 
     Attachment A attached hereto provides computer listings of preferred PGC abstractions source code according to the invention. For clarity sake, compilation has already been completed. Stated alternatively, the no-ops initially included in the skeleton-form PGC layout structure have been replaced by indices and the indices have been resolved to source and target identifiers using the discussed compiler and compilation methods. 
     As shown in attachment A, the preferred PGC abstractions utilize a number of DVD player registers. According to the DVD specification, each DVD player includes 16 general purpose registers (“GPs”), and 20 system registers (“SPs”). The GPs are functionally undefined and merely “available for use” by movie title control program PGCs. Conversely, the SPs have fully defined purposes consistent with DVD player operation and movie title control program interfacing. 
     The preferred GPs utilization and corresponding naming conventions according to the invention are indicated in the following chart. As shown, PGC abstractions exclusively utilize only 5 GPs, leaving a maximized number of remaining GPs available for adding further capabilities. 
     
       
         
           
               
               
               
             
               
                   
               
               
                 Register 
                 Referenced as 
                 Description 
               
               
                   
               
             
            
               
                 GP10 
                 Stream Select 
                 Bit 15 = Select audio stream on/off 
               
               
                   
                   
                 Bit 14 = Select subtitle stream on/off 
               
               
                   
                   
                 Bit 13 = Select angle stream on, off 
               
               
                   
                   
                 Bits 10-12 = Audio stream number 
               
               
                   
                   
                 Bits 7-9 = Angle stream number 
               
               
                   
                   
                 Bits 0-6 = Subtitle stream number 
               
               
                 GP12 
                 Target Movie Number 
                 Stored number = Movie number 
               
               
                 GP13 
                 Target Button Number 
                 Stored number = Button number 
               
               
                 GP14 
                 Target Chapter Number 
                 Stored number = Chapter number 
               
               
                 GP15 
                 Temporary Register 
                 Stored number = value used with 
               
               
                   
                   
                 current PGC 
               
               
                 SP7 
                 Last Chapter Played 
                 DVD player fills the register with the 
               
               
                   
                   
                 number of the last chapter played 
               
               
                 SP8 
                 Last Highlighted Button 
                 DVD player fills the register with the 
               
               
                   
                   
                 number of the last highlighted button 
               
               
                   
               
            
           
         
       
     
     As illustrated by the register utilization chart, GPs are utilized by source PGC abstractions primarily for designating (i.e. resolving an available connection to) target PGC abstractions and for passing to the targets parameters affecting target operation. The GPs are further utilized by target PGC abstractions primarily for establishing, manipulating and recalling localized variables (i.e. relating to a currently executing PGC command set). 
     For example, at a time prior to initiating playback of a chapter, a source PGC abstraction stores a value in GP10 (“stream select”). That value will later indicate to a target PGC which audio, subtitle and/or angle stream is to be selected for movie playback. A further example is that, at a time prior to routing control to a target PGC abstraction, a source PGC abstraction stores a target&#39;s designation in a combination of registers GP12 (“Movie Number”) and GP14 (“Chapter Number”) for a movie target or GP13 (“Button Number”) for a menu target. Finally, PGC abstractions preferably utilize GP15 to temporarily store values, typically for use within a current PGC operation. 
     In most cases, only a portion of a given register (“register bits”) are utilized, while conversely, a given register may be used for multiple purposes, as seen in the utilization of GP10 in the register chart. Those skilled in the art will appreciate, given the discussion herein, that the preferred embodiment enables certain advantages. Among these are that a single register or register set can be designated in all cases for similar purposes, thereby minimizing complexities, the number of registers required and the number of commands required within a PGC without detrimentally affecting routing or parameter passing flexibility. Similarly, operations required to parse register data containing multiple data values are not needed. Other arrangements consistent with the teachings of the invention however, are likely in view of other applications facilitated by these teachings and in accordance with the scope and spirit of the invention. 
     While the present invention has been described herein with reference to a particular embodiment thereof, a latitude of modification, various changes and substitutions are intended in the foregoing disclosure, and it will be appreciated that in some instances some features of the invention will be employed without a corresponding use of other features without departing from the spirit and scope of the invention as set forth. 
     
       
         
           
               
             
               
                 APPENDIX A 
               
               
                   
               
               
                 PGC ABSTRACTION SOURCE CODE 
               
               
                   
               
             
            
               
                 Exemplary Included Movies/Menus 
               
               
                   
               
            
           
           
               
               
            
               
                   
                 2 Movies with 3 chapters each 
               
               
                   
                 2 Menus with 4 Buttons each 
               
               
                   
               
            
           
           
               
            
               
                 Exemplary Included Connections 
               
            
           
           
               
               
               
               
            
               
                   
                 Connections Source 
                   
                 Connections Target 
               
               
                   
               
               
                   
                 Movie 1: Chapter 1 Remote Key 
                 -&gt; 
                 Menu 1: Button 1 
               
               
                   
                 Movie 1: Chapter 2 Remote Key 
                 -&gt; 
                 Menu 1: Button 2 
               
               
                   
                 Movie 1: Chapter 3 Remote Key 
                 -&gt; 
                 Menu 1: Button 3 
               
               
                   
                 Movie 1: Chapter 3 End 
                 -&gt; 
                 Menu 1: Button 1 
               
               
                   
                 Movie 2: Chapter 1 Remote Key 
                 -&gt; 
                 Menu 2: Button 1 
               
               
                   
                 Movie 2: Chapter 2 Remote Key 
                 -&gt; 
                 Menu 2: Button 2 
               
               
                   
                 Movie 2: Chapter 3 Remote Key 
                 -&gt; 
                 Menu 2: Button 3 
               
               
                   
                 Movie 2: Chapter 3 End 
                 -&gt; 
                 Menu 2: Button 1 
               
               
                   
                 Menu 1: Button 1 
                 -&gt; 
                 Movie 1: Chapter 1 
               
               
                   
                 Menu 1: Button 2 
                 -&gt; 
                 Movie 1: Chapter 2 
               
               
                   
                 Menu 1: Button 3 
                 -&gt; 
                 Movie 1: Chapter 3 
               
               
                   
                 Menu 1: Button 4 
                 -&gt; 
                 Menu 2: Button 1 
               
               
                   
                 Menu 2: Button 1 
                 -&gt; 
                 Movie 2: Chapter 1 
               
               
                   
                 Menu 2: Button 2 
                 -&gt; 
                 Movie 2: Chapter 2 
               
               
                   
                 Menu 2: Button 3 
                 -&gt; 
                 Movie 2: Chapter 3 
               
               
                   
                 Menu 2: Button 4 
                 -&gt; 
                 Menu 1: Button 1 
               
               
                   
               
            
           
           
               
            
               
                 1. VIDEO MANAGER (“VMGM”) Program Chains (“PGCs”) 
               
            
           
           
               
               
            
               
                 First Play PGC 
                   
               
               
                 PRE_CMD#1: MovI GP14, 1 
                 // Target = Chapter 1 
               
               
                 PRE_CMD#2: MovI GP12, 1 
                 // Target = Movie 1 
               
               
                 PRE_CMD#3: JumpSS VMGM PGCI 2 
                 // Jump To Movie Router 
               
               
                 Title PGC (PGC #1) 
                   
               
               
                 PRE_CMD#1: MovI GP13, 1 
                 // Target = Button 1 
               
               
                 PRE_CMD#2: LinkPGCN PGCN = 3 
                 // Jump to Menu 1 
               
               
                 Movie Router PGC (VMGM PGC #2) 
                   
               
               
                 PRE_CMD#1: MovI GP15, 1 
                 // Setup Comparision to 1 
               
               
                 PRE_CMD#2: EQ GP15, GP12 JumpTT TTN = 1 
                 // If Target Movie = 1, 
               
               
                   
                   goto Movie1 
               
               
                 PRE_CMD#3: MovI GP15, 2 
                 // Setup Comparision to 2 
               
               
                 PRE_CMD#4: EQ GP15, GP12 JumpTT TTN = 2 
                 // If Target Movie = 2, 
               
               
                   
                   goto Movie 2 
               
               
                 PRE_CMD#5: JumpSS First Play 
                 // Should never get here 
               
               
                 Menu 1 Display PGC (VMGM PGC #3) 
                   
               
               
                 PRE_CMD#1: Mov GP15, GP13 
                 // Put target button no. 
               
               
                   
                   into temp storage 
               
               
                 PRE_CMD#2: MulI GP15, 1024 
                 // Shift Button number by 
               
               
                   
                   10 Bits to the left 
               
               
                 PRE_CMD#3: SetHL_BTNN HLP = GP15 
                 // Highlight target button 
               
               
                   
                   in menu; display menu 
               
               
                 Menu 2 Display PGC (VMGM PGC #4) 
                   
               
               
                 PRE_CMD#1: Mov GP15, GP13 
                 // Put target button no. 
               
               
                   
                   into temp storage 
               
               
                 PRE_CMD#2: MulI GP15, 1024 
                 // Shift Button number by 
               
               
                   
                   10 Bits to the left 
               
               
                 PRE_CMD#3: SetHL_BTNN HLP = GP15 
                 // Highlight target Button 
               
               
                   
                   in menu; display menu 
               
               
                 Menu 1 Button Router (VMGM PGC #5) 
                   
               
               
                 PRE_CMD#1: Mov GP15, SP8 
                 // Put last highlighted 
               
               
                   
                   button in temp storage 
               
               
                 PRE_CMD#2: DivI GP15, 1024 
                 // Shift Button number 10 
               
               
                   
                   bits to the right 
               
               
                 PRE_CMD#3: NEI GP15, 1 GoTo CMDNUM = 7 
                 // If button number ≠ 1, 
               
               
                   
                   goto CMD #7 
               
               
                 PRE_CMD#4: MovI GP14, 1 
                 // Target = Chapter 1 
               
               
                 PRE_CMD#5: JumpTT TTN = 1 
                 // Jump Movie 1 
               
               
                 PRE_CMD#6: Nop 
                   
               
               
                 PRE_CMD#7: NEI GP15, 2 GoTo CMDNUM = 11 
                 // If button number ≠ 2, 
               
               
                   
                   goto CMD #11 
               
               
                 PRE_CMD#8: MovI GP14, 2 
                 // Target = Chapter 2 
               
               
                 PRE_CMD#9: JumpTT TTN = 1 
                 // Jump Movie 1 
               
               
                 PRE_CMD#10: Nop 
                   
               
               
                 PRE_CMD#11: NEI GP15, 3 GoTo CMDNUM = 15 
                 // If button number ≠ 3, 
               
               
                   
                   goto CMD #15 
               
               
                 PRE_CMD#12: MovI GP14, 3 
                 // Target = Chapter 3 
               
               
                 PRE_CMD#13: JumpTT TTN = 1 
                 // Jump Movie 1 
               
               
                 PRE_CMD#14: Nop 
                   
               
               
                 PRE_CMD#15: MovI GP13, 1 
                 // Target = Button 1 
               
               
                 PRE_CMD#16: LinkPGCN PGCN = 4 
                 // Jump Menu 2 
               
               
                 Menu 1 Button Router (VMGM PGC #6) 
                   
               
               
                 PRE_CMD#1: Mov GP15, SP8 
                 // Put last highlighted 
               
               
                   
                   button in temp storage 
               
               
                 PRE_CMD#2: DivI GP15, 1024 
                 // Shift Button number 10 
               
               
                   
                   bits to the right 
               
               
                 PRE_CMD#3: NEI GP15, 1 GoTo CMDNUM = 7 
                 // If button number ≠ 1, 
               
               
                   
                   goto CMD #7 
               
               
                 PRE_CMD#4: MovI GP14, 1 
                 // Target = Chapter 1 
               
               
                 PRE_CMD#5: JumpTT TTN = 2 
                 // Jump Movie 2 
               
               
                 PRE_CMD#6: Nop 
                   
               
               
                 PRE_CMD#7: NEI GP15, 2 GoTo CMDNUM = 11 
                 // If button number ≠ 2, 
               
               
                   
                   goto CMD #11 
               
               
                 PRE_CMD#8: MovI GP14, 2 
                 // Target = Chapter 2 
               
               
                 PRE_CMD#9: JumpTT TTN = 2 
                 // Jump Movie 2 
               
               
                 PRE_CMD#10: Nop 
                   
               
               
                 PRE_CMD#11: NEI GP15, 3 GoTo CMDNUM = 15 
                 // If button number ≠ 3, 
               
               
                   
                   goto CMD #15 
               
               
                 PRE_CMD#12: MovI GP14, 3 
                 // Target = Chapter 3 
               
               
                 PRE_CMD#13: JumpTT TTN = 2 
                 // Jump Movie 2 
               
               
                 PRE_CMD#14: Nop 
                   
               
               
                 PRE_CMD#15: MovI GP13, 1 
                 // Target = Button 1 
               
               
                 PRE_CMD#16: LinkPGCN PGCN = 3 
                 // Jump Menu 1 
               
               
                 Title 1 End Router Chapter 3 (VMGM PGC #7) 
                   
               
               
                 PRE_CMD#1: MovI GP13, 1 
                 // Target = Button 1 
               
               
                 PRE_CMD#2: LinkPGCN PGCN = 3 
                 // Jump Menu 1 
               
               
                 Title 2 End Router Chapter 3 (VMGM PGC #8) 
                   
               
               
                 PRE_CMD#1: MovI GP13, 1 
                 // Target = Button 1 
               
               
                 PRE_CMD#2: LinkPGCN PGCN = 4 
                 // Jump Menu 2 
               
            
           
           
               
            
               
                 2. Video Title Segment #1 (“VTS-1”) PGCs 
               
            
           
           
               
               
            
               
                 Movie 1 Display PGC (VTS PGC #1) 
                   
               
               
                 PRE_CMD#1: Mov GP15, GP14 
                 // Move Target Chapter 
               
               
                   
                   into temp storage 
               
               
                 PRE_CMD#2: MovI GP14, 0 
                 // Zero Target Chapter 
               
               
                   
                   register 
               
               
                 PRE_CMD#3: EQI GP15, 1 LinkPGN PGN = 1 
                 // If Chapter=1, Goto 
               
               
                   
                   Program #1 (Chapter 1) 
               
               
                 PRE_CMD#4: EQI GP15, 2 LinkPGN PGN = 2 
                 // If Chapter=2, Goto 
               
               
                   
                   Program #2 (Chapter 2) 
               
               
                 PRE_CMD#5: EQI GP15, 3 LinkPGN PGN = 3 
                 // If Chapter=3, Goto 
               
               
                   
                   Program #3 (Chapter 3) 
               
               
                 End CMD for Movie 1 Chapter 3 (VTS PGC #1) 
                   
               
               
                 C_CMD#1: CallSS VMGM_PGCN = 7, DOMAINID = 3 
                 // Jump to VMGM PGC #7 
               
               
                   
                   (Title1, End-router for 
               
               
                   
                    Chapter 3) 
               
               
                 Chapter Router PGC (VTSM PGC #1) 
                   
               
               
                 PRE_CMD#1: Mov GP15, SP7 
                 // Put last played chapter 
               
               
                   
                   into temp storage 
               
               
                 PRE_CMD#2: Nop 
                   
               
               
                 PRE_CMD#3: Nop 
                   
               
               
                 PRE_CMD#4: Nop 
                   
               
               
                 PRE_CMD#5: GEI GP15, 2 GoTo CMDNUM = 9 
                 // If last chapter ≧ 2, 
               
               
                   
                   goto CMD #9 
               
               
                 PRE_CMD#6: MovI GP13, 1 
                 // Target = Button 1 
               
               
                 PRE_CMD#7: JumpSS VMGM_PGCN = 3, DOMAINID = 3 
                 // Jump to Menu 1 
               
               
                 PRE_CMD#8: Nop 
                   
               
               
                 PRE_CMD#9: GEI GP15, 3 GoTo CMDNUM = 13 
                 // If last chapter ≧ 3, 
               
               
                   
                   goto CMD #13 
               
               
                 PRE_CMD#10: MovI GP13, 2 
                 // Target = Button 2 
               
               
                 PRE_CMD#11: JumpSS VMGM_PGCN = 3, DOMAINID = 3 
                 // Jump to Menu 1 
               
               
                 PRE_CMD#12: Nop 
                   
               
               
                 PRE_CMD#13: MovI GP13, 3 
                 // Target = Button 3 
               
               
                 PRE_CMD#14: JumpSS VMGM_PGCN = 3, DOMAINID = 3 
                 // Jump to Menu 1 
               
            
           
           
               
            
               
                 3. Video Title Segment #2 (“VTS-2”) PGCs 
               
            
           
           
               
               
            
               
                 Movie 2 Display PGC (VTS PGC #1) 
                   
               
               
                 PRE_CMD#1: Mov GP15, GP14 
                 // Move Target Chapter 
               
               
                   
                   into temp storage 
               
               
                 PRE_CMD#2: MovI GP14, 0 
                 // Zero Target Chapter 
               
               
                   
                   register 
               
               
                 PRE_CMD#3: EQI GP15, 1 LinkPGN PGN = 1 
                 // If Chapter=1, Goto 
               
               
                   
                   Program #1 (Chapter 1) 
               
               
                 PRE_CMD#4: EQI GP15, 2 LinkPGN PGN = 2 
                 // If Chapter=2, Goto 
               
               
                   
                   Program #2 (Chapter 2) 
               
               
                 PRE_CMD#5: EQI GP15, 3 LinkPGN PGN = 3 
                 // If Chapter=3 Goto 
               
               
                  Program #3 (Chapter 3) 
                   
               
               
                 End CMD for Movie 2 Chapter 3 (VTS PGC #1) 
                   
               
               
                 C_CMD#1: CallSS VMGM_PGCN = 7, DOMAINID = 3 
                 // Jump to VNGM PGC #8 
               
               
                   
                  (Title 2 End Router 
               
               
                   
                   Chapter 3) 
               
               
                 Chapter Router PGC (VTSM PGC #1) 
                   
               
               
                 PRE_CMD#1: Mov GP15, S97 
                 // Put last played chapter 
               
               
                   
                   into temp storage 
               
               
                 PRE_CMD#2: Nop 
                   
               
               
                 PRE_CMD#3: Nop 
                   
               
               
                 PRE_CMD#4: Nop 
                   
               
               
                 PRE_CMD#5: GEI GP15, 2 GoTo CMDNUM = 9 
                 // If last chapter ≧ 2, 
               
               
                   
                   goto CMD #9 
               
               
                 PRE_CMD#6: MovI GP13, 1 
                 // Target = Button 1 
               
               
                 PRE_CMD#7: JumpSS VMGM_PGCN = 4, DOMAINID = 3 
                 // Jump to Menu 2 
               
               
                 PRE_CMD#8: Nop 
                   
               
               
                 PRE_CMD#9: GEI GP15, 3 GoTo CMDNUM = 13 
                 // If last chapter ≧ 3, 
               
               
                   
                   goto CMD #13 
               
               
                 PRE_CMD#10: MovI GP13, 2 
                 // Target = Button 2 
               
               
                 PRE_CMD#11: JumpSS VMGM_PGCN = 4, DOMAINID = 3 
                 // Jump to Menu 2 
               
               
                 PRE_CMD#12: Nop 
                   
               
               
                 PRE_CMD#13: MovI GP13, 3 
                 // Target = Button 3 
               
               
                 PRE_CMD#14: JumpSS VMGM_PGCN = 4, DOMAINID = 3 
                 // Jump to Menu 2

Metadata:
Filing Date: 20060927
Publication Date: 20120626
Grant Date: 20120626
Priority Date: 19980121
Inventors: BRODERSEN RAINER
WALLACE GREGORY KENT
Assignee: APPLE INC
CPC Classifications: [{"code": "H04N5/85", "inventive": true, "first": true, "tree": "[]"}, {"code": "G11B27/034", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04N9/8042", "inventive": true, "first": false, "tree": "[]"}, {"code": "G11B27/34", "inventive": true, "first": false, "tree": "[]"}, {"code": "G11B2220/213", "inventive": false, "first": false, "tree": "[]"}, {"code": "G11B2220/2562", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04N5/85", "inventive": true, "first": true, "tree": "[]"}, {"code": "G11B2220/213", "inventive": false, "first": false, "tree": "[]"}, {"code": "G11B27/034", "inventive": true, "first": false, "tree": "[]"}, {"code": "G11B2220/2562", "inventive": false, "first": false, "tree": "[]"}, {"code": "G11B27/34", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04N9/8042", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 21744951