Abstract:
A tool for scheduling the delivery of media objects within varying constraints of available bandwidth. In a preferred embodiment in which the invention is enabled by software executable on a general purpose multimedia grade computer, a system designer orchestrates the playback of a series of media objects on a playback “score” analogous to a musical score. The media objects are represented on the playback score as playback icons. Responsive to the designer&#39;s manipulation of playback icons on the playback score, the present invention further creates and displays a corresponding download score, in which download icons (corresponding to playback icons on the playback score) are deployed and arranged to fill up a displayed “pipe” of available bandwidth. The topographical area of the download icons, as displayed, corresponds to the data size of the media objects. The download icons are displayed as rectangular or square-cornered polygonal shapes. As the playback score becomes more information-rich, the pipe tends to fill to capacity with download icons. Eventually, as more information is added, delivery tends towards an error condition where download can no longer keep up with demand (i.e. the pipe is full). When this happens, the invention highlights this condition to the designer. The designer must then take action to correct the error condition so that delivery of media objects is once again compatible with playback. Alternatively, in a second embodiment, the system degrades the content of media objects according to preselected sequences and conditions. The corresponding reduction in data-richness of degraded media objects causes the delivery thereof to again be compatible with playback.

Description:
RELATED APPLICATIONS 
     This application is a continuation of application Ser. No. 08/948,844, filed on Oct. 10, 1997, now U.S. Pat. No. 5,859,641, entitled AUTOMATIC BANDWIDTH ALLOCATION IN MULTIMEDIA SCRIPTING TOOLS, issued Jan. 12, 1999. This application is also related to commonly-assigned (1) U.S. Pat. No. 6,075,843, entitled USER DEVICE-DEPENDENT TRANSACTION MODEL, issued Jun. 13, 2000; and (2) U.S. Pat. No. 5,841,438, entitled VISUAL AID FOR BANDWIDTH ALLOCATION IN MULTIMEDIA SCRIPTING TOOLS, issued Jan. 12, 1999; all of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD OF THE INVENTION 
     This invention relates generally to the representation of electronic information, and more specifically to representing data in a scripting tool. 
     BACKGROUND OF THE INVENTION 
     The above-referenced, commonly assigned and co-pending U.S. application entitled USER DEVICE-INDEPENDENT TRANSACTION MODEL (the “UDT Invention”) discloses a model for delivering generic information from a central system to connected users whose terminal devices communicate in varying formats and/or media. The UDT Invention teaches the use of Transaction Templates (TTs) and User Device Templates (UDTs) which script and condition device-independent information exchanges between the system and users to be compatible with the different format and media requirements of said users&#39; various terminal devices. In the UDT Invention, TTs enable an exchange of information between the system and the user in the information&#39;s most basic, generic format. UDTs associated with each TT then condition the information exchanged in the TT to be format- and media-compatible with the device through which the user is communicating with the system. The same information exchange may thus be enabled in a variety of environments according to the formats and media supported by various users&#39; terminal devices. 
     A constraint placed upon the effectiveness of UDTs, however, is the available bandwidth in which to deliver information in the scripted formats and/or media. This is particularly applicable when the information is to be delivered in several media, the display of which to the user is to appear simultaneous and/or synchronized. It will be appreciated that, according to the UDT Invention, a UDT may be designed wherein an information transaction is scripted to appear to the user as a sophisticated multimedia experience, including sound, video, graphics and text, assuming that all of these media are supported by the user&#39;s multimedia PC. If the available, bandwidth in the interconnecting link between system and user is insufficient to deliver all this information according to the time constraints of the script, however, this multimedia UDT will operate at reduced effectiveness. 
     One solution to this problem of insufficient bandwidth is for the user simply to sit and wait for a sufficient amount of information to have been delivered to begin the script with confidence that it can be completed without running out of information mid-script. 
     Another solution is to redesign either (or both) the sequence or the content of the script, so that the script&#39;s delivery is either slower or less data-rich. For example, a display of merely ornamental graphics could be delayed or removed to make room for the earlier delivery of more strategic information. Alternatively, a media object may be degraded (e.g. sampling rate reduced) to make the object less data-rich. 
     A yet further solution is to preload information in advance of its being needed by the script. This solution may be enabled using excess bandwidth in early parts of a particular script. This may be done on an individual script basis, alternatively, when the system knows specifically that a later script will be played, information for that later script may be preloaded on the user&#39;s terminal device using excess bandwidth during an earlier script. 
     Whichever solution is chosen, however, it would be highly advantageous to have a computer tool that enables delivery of information to be scheduled so as to optimize available bandwidth, while still enabling the playing of a multimedia script with minimal startup delay and no interruptions. Using this tool, the system designer would be able to orchestrate scripts linked to an optimum delivery schedule of the underlying media objects. When insufficient bandwidth is available for an instantaneous playback, the designer would further be able to make choices among the alternatives described above, such as delaying startup, redesigning script sequence and/or content, or preloading information, so as to make full and best use of available bandwidth. Further, in the context of UDTs according to the UDT Invention, the designer would be able to design an array of UDTs in which a particular information exchange could be scripted to be delivered at various levels of multimedia sophistication according to predetermined increments of available bandwidth. 
     Methods of identifying and quantifying available bandwidth in interconnecting links are known in the art. It will therefore be seen that given an array of UDTs as described above, each designed to deliver media objects on a schedule that fits within the constraints of an incrementally different bandwidth, it would then become possible, under the UDT Invention, to select a UDT to match the available bandwidth recognized in a particular interconnecting link. 
     Orchestrating the delivery of media objects within available bandwidth would further be advantageously enabled in a graphical environment on a general purpose multimedia-grade desktop computer. For example, scripting tools are known in the art where a designer may orchestrate the playback of a series of media objects by creating, adapting and executing a horizontal bar chart, much like a “musical score.” There is a need in the art to attach this known orchestration and playback capability to corresponding functionality that shows how playback choices are affected by the constraints of delivery bandwidth. In this way, a designer may design, see, hear and manipulate scripts that also take delivery variables such as available bandwidth into account. 
     The disclosure of above-referenced U.S. application VISUAL AID FOR BANDWIDTH ALLOCATION IN MULTIMEDIA SCRIPTING TOOLS (the “Manual Invention”) (same effective filing data as the present application) describes an invention in which the system displays a “download score,” viewable in combination with orchestration and playback functionality. The download score enables a system designer to develop manually a “download script” of media objects that delivers information within a fixed bandwidth constraint (or “pipe”) to meet the demand for data in the playback functionality. According to the Manual Invention, the system designer may adapt the shape of “download icons” on the download store so as to fit within the pipe. When all the download icons fit within the pipe without creating an error condition, the system designer knows that the media objects that he or she has selected and scripted on the playback wore are deliverable within the bandwidth constraint that he or she selected on the download score. An disclosed in the Manual Invention, however, the designer may have adjust the playback script several times by a “trial and error” in order to create a playback score that is deliverable through the pipe. While the Manual Invention is useful for some applications, it is alternatively advantageous to be able to automate selected aspects of the creation of the download script according to predefined delivery rules, where the system automatically deploys download icons within the pipe according to the delivery rules and then adjusts their shape to fill up available bandwidth. In this way, the system designer could focus on developing aesthetically pleasing playback scripts deliverable within constraints of bandwidth without having to spend time manually adapting the shape of media objects to fit within a pipe on a display. 
     SUMMARY OF THE INVENTION 
     For the purposes of this disclosure, “media object” or “object” is defined as an information structure, such as a file, which, when executed on a computer, plays the information to a user. A media object may be, for example, a sound clip, or a video clip, or a graphic. Media objects may come in any size or format suitable to be intelligible to a user through a variety of terminal devices. 
     In distinction to the foregoing definition of a media object, this disclosure also defines a “media icon” or “icon” as a representation of a media object on a terminal device, usually a computer screen. 
     The present invention is directed to a graphical representation of media object delivery in a limited bandwidth wherein the delivery of these objects may be optimized to make the best use of the available bandwidth. In a preferred embodiment, the invention presents three screens, or “views” to the system designer. 
     The designer advantageously first orchestrates a multimedia presentation by deploying media objects as a script on a “playback” score. The playback score allows the system designer to select and schedule media objects to be played back in overlapping sequence so as to make a predefined presentation. The playback score shows the media objects represented as playback icons relatively deployed on a time-indexed schedule, much like a musical score shows notes represented as recognizable marks on a stave. The designer further inputs additional parameters regarding the scripted media objects themselves. These additional parameters include media object size (when file size is not already known by the computer system), sequencing requirements with other objects, synchronicity requirements with other objects, and so on. Other media object parameters, such as time to start and time to stop, may also be recorded by the system from the designer&#39;s placement of the playback icons on the playback score. 
     A second screen, or “view” corresponding to the playback score is the runtime view. Advantageously viewable concurrently with the playback score by arranging multiple windows on the screen, the runtime view allows the system designer to see the executed presentation of the playback score in real time. In the runtime view, the system defaults to playing back the playback score at the same speed that the presentation is orchestrated on the playback score, from a start point to an end point in time as marked by the designer on the playback score. The designer may also speed up or slow down the runtime view&#39;s execution as required to observe particular details. It will be understood, however, that the runtime view is a “slave screen” as far as orchestration of the playback score itself is concerned. That is, the designer uses the playback score as the tool to ordain the selection and substantive scheduling of media objects in making a presentation. The runtime view merely allows the designer to see the results of his or her work. 
     As the playback score and the corresponding runtime view are being developed, the present invention also develops a download score. This screen, or “view,” is a third view corresponding to the playback score, again also viewable by switching computer screens or manipulating multiple windows. In the present invention, the download score is a tool for the system designer to we the script embodied by the playback score (the “Playback Script”) arranged by the system into a corresponding delivery schedule within predefined constraints of bandwidth (the “Download Scripts”). The system designer may thus create a Playback Script with a view to enabling the script to be played back intelligibly over a connection of limited bandwidth. 
     The system automatically or manually arranges download icons on the download score, each download icon corresponding to a playback icon on the playback score. The download score also displays a constraint of bandwidth previously ordained by the system designer, this constraint advantageously displayed as a separation of parallel lines, referred to herein as a “pipe”. The system automatically or manually arranges download icons within the pipe according to predefined “delivery rules”, such a (1) not exceeding available bandwidth (i.e. not straying outside the pipe), (2) using up all available bandwidth within the pipe, and (3) ensuring that delivery of a particular media object on the Download Script keeps up with demand for it on the Playback Script. 
     As noted in a preferred embodiment, the present invention is enabled on software executable by a general purpose desktop computer. The computer is advantageously a multimedia-grade computer with capability to display alternately or concurrently the playback score, the runtime view and the download score, and further to play both visual and aural media objects in the runtime view according to the Playback Script. The software ideally runs under a well-known user-friendly operating system environment such as Microsoft® Windows. 
     As will be described in further detail below, in a preferred embodiment the system designer sees media objects as icons deployed on the playback score in an environment similar to other scripting tools known in the art. On the corresponding download score, however, the system designer sees media objects as icons distributed graphically within the “pipe” of available bandwidth. The width of the pipe, of course, may be varied, scaled to represent corresponding variation in available bandwidth. The length of the pipe is indexed to represent time. The topographical size of an icon, when deployed in the pipe, thus represents the corresponding media object&#39;s data size. The interrelated shapes and relative location of the icons as deployed within the “pipe” thereby represent a delivery schedule of corresponding media objects within available bandwidth. As a result, the designer may develop Playback Scripts of media objects that are compatible with known constraints of bandwidth. If the designer takes an action on the playback score that causes a delivery rule error (e.g. pipe boundaries exceeded, delivery cannot keep up with demand), then the invention alerts the designer with an alarm. Advantageously, the computer highlights the icon(s) out of compliance with the rule on both playback and download scores. Different highlights may indicate different problems. The designer must then make adjustments (e.g. increase bandwidth, change media object content, move media objects, drop or substitute media objects) to compensate. 
     In a second embodiment, the system automatically or manually degrades the content of media objects (by, for example, resampling) according to preselected sequences and conditions ordained by the user. The corresponding reduction in data-richness of degraded media objects causes the Download Script to again be compatible with the Playback Script. 
     A primary application for the invention is thus the design of UDTs, so that bandwidth constraints may be taken into account when scripting media objects to be delivered to a user to enable an information transaction. The present invention is nonetheless not limited to this UDT application, and may be used whenever media object delivery needs to be optimability. 
     In UDT applications, it will be seen that an array of UDTs may be designed for each information transaction accommodating media object delivery not only in formats supported by the user&#39;s terminal device, but also on a schedule supportable by the bandwidth of the interconnecting link. Advantageously, different UDTs support different ranges of bandwidth in which media objects are deliverable to support correspondingly information-rich scripts. 
     It is therefore a technical advantage of the present invention to optimize available bandwidth in delivering media objects. 
     It is a further technical advantage of the present invention to facilitate creation of an array of media object Download Scripts, each generally directed to delivering information in formats and/or media compatible with a particular receiving terminal device, each further specifically delivering selected media objects on a schedule deliverable within incremental ranges of available bandwidth. 
     It is a further object of the present invention to provide a designer with an interactive graphical tool with a playback score to design and adjust media object Playback Scripts within various bandwidth limitations. By also providing a companion download score on which the system automatically or manually arranges download icons to fit within a fixed pipe of bandwidth, the tool enables the designer to schedule the delivery of the media objects to meet the demand for data in the Playback Script. 
     It is a still further object of a preferred embodiment of the present invention to locate bandwidth automatically, so that the system designer can spend more time concentrating on aesthetic aspects of the multimedia presentation design. The automated aspect of a preferred embodiment of the invention allows the designer to make variations to the Playback Script based on aesthetic considerations, and then see/hear the results in the runtime view. Meanwhile, a preferred embodiment of the invention automatically allocates and reallocates bandwidth in the Download Script responsive to the designer&#39;s changes to the Playback Script, and then alerts the designer if such changes have caused the Download Script now to violate one or more of the predefined delivery rules. The designer thus spends very little (if any) time adapting download icons on the download score to develop a Download Script (the system now doing this automatically), and the designer may instead spend more time developing aesthetically pleasing multimedia presentations using the Playback Script. 
     It is a still further object of the present invention to optionally enable automatic or manual degradation of media objects according to designer-selectable criteria in compiling a Download Script that is compatible with the Playback Script. 
     The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: 
     FIG. 1 illustrates an exemplary computer system on which a preferred embodiment of the present invention may advantageously be run; 
     FIG. 2A illustrates an exemplary playback score  201  a used according to the present invention to orchestrate the playback of media objects; and 
     FIG. 2B illustrates runtime view  231  corresponding to the exemplary playback score  201  illustrated in FIG.  2 A. 
     FIG. 2C illustrates download score  251  corresponding to the exemplary playback score illustrated in FIG.  2 A. 
     FIG. 2D illustrates exemplary download score  251  in which download icon  257 H is highlighted to indicate that delivery thereof as currently ordained on download score  251  cannot keep up with demand on the corresponding playback score  201 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A preferred embodiment of the present invention is enabled on a general purpose desktop computer, advantageously “multimedia” grade, as illustrated on FIG.  1 . Referring to FIG. 1, system  100  comprises CPU  101 , having an internal processor, memory, and a mass storage device such as a hard drive (these internal components not illustrated). CPU  101  also advantageously includes drives  103  to read and write to external mass storage devices such as CD  105  or diskette  107 . User input is enabled via standard peripheral devices such as keyboard  109 , mouse  111  and microphone  113 . System output is enabled visually on monitor  115 , and audibly on speakers  117 . 
     In a preferred embodiment, the present invention is a software tool executable on system  100 , although it will be understood that the principles and scope of the present invention are not limited to any particular specific hardware architecture or configuration. The present invention may be stored on any suitable mass storage device as a computer program product comprising instructions and logic readable and executable by system  100 . Such suitable mass storage devices include CD  105 , diskette  107 , or hard drive within CPU  101  (not illustrated). Likewise, data to be processed by the present invention, including media objects and selected instructions from the user, may be stored on system  100  as computer-readable riles on mass storage devices such as CD  105 , diskette  107 , or hard drive within CPU  101  (not illustrated). 
     With reference now to FIGS. 2A,  2 B and  2 C, and with continuing reference to the components illustrated on FIG. 1, the main elements comprising the tool of the present invention are shown. FIG. 2A illustrates playback score  201  in a style similar to graphical media object orchestration and playback displays known in the art. Scaled playback grid  203  shows time indexed on the x-axis and a plurality of playback icons  205  disposed down the y-axis. Each playback icon  205  represents a corresponding media object to be played within a time window indicated by the left and right extremities of the icon  205  as located on the x-axis of playback grid  203 . The system designer may add, drop and move playback icons  205  around playback grid  203 , effecting temporal changes in the “orchestral” playback sequence of the combined corresponding playback. Other aesthetic effects are also advantageously available, such as, for example, speed of playback of individual media objects, volume of playback of audible objects etc. As a result, a multimedia presentation may be orchestrated, including voice, text, graphics, photographs and music, according to a script represented by playback icons  205  deployed on playback grid  203 . 
     FIG. 2B illustrates a runtime view  231  corresponding to playback score  201  on FIG.  2 A. The system designer switches to runtime view  231  to see and hear the multimedia presentation orchestrated on playback score  201 . In the examples used in FIGS. 2A and 2B, playback icons  205  on FIG. 2A correspond to audiovisuals on FIG. 2B as follows on Table 1: 
     
       
         
               
               
               
             
           
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 Playback Icon 
                 Audiovisual item 
               
               
                   
                 on FIG. 2A 
                 on FIG. 2B 
               
               
                   
                   
               
             
             
               
                   
                 Graphic 2 
                 232 
               
               
                   
                 Graphic 1 
                 233 
               
               
                   
                 Text 1/Text 2 
                 234 
               
               
                   
                 Video 1 
                 235 
               
               
                   
                 Sound 1 
                 236 
               
               
                   
                 Mueic 1 
                 237 
               
               
                   
                   
               
             
          
         
       
     
     Advantageously, the system designer can switch to runtime view  231  at any time to view all or part; of the multimedia presentation orchestrated on playback score  201 , responsive to start and stop markers set on playback score  201 . The system designer may further advantageously vary the replay speed of runtime view  231  in order to give attention to specific aspects. It will be understood, however, that runtime view  231  is a “slave” replay to playback wore  201 , and any substantive changes to the content of the orchestrated Playback Script must be made on playback score  201 . To this extent, runtime view  231  merely allows the designer to see the results of his or her work. 
     Turning now to FIG. 2C, the present invention provides a third “view” of the multimedia presentation being orchestrated on playback score  201  on FIG.  2 A. In a preferred embodiment, playback score  201 , runtime view  231  and download score  251  are further viewable by the system designer substantially concurrently. Any method known in the art to enable this is satisfactory, such as, for example, splitting a screen into tiles or “switching” between screens, or viewing separate windows. 
     FIG. 2C illustrates a download score  251  as created by the present invention. Download score  251  corresponds with playback score  201  such that changes to playback wore  201  are automatically reflected in download score  251 . Also analogous to playback wore  201 , download score  251  provides download grid  253  indexed on the x-axis to represent time. It is preferable, but not required, for the temporal scale on the x-axes of both playback and download grids  201  and  251  to be substantially the same in a default setting. Advantageously, however, the system designer may vary the x-axis scales of playback and download grids  201  and  251  independently. 
     In distinction to playback grid  203  as shown on FIG. 2A, however, download grid  253  on FIG. 2C also has a scaled y-axis. This y-axis represents bandwidth, and is advantageously indexed in increments of kilobits per second (kbps). Optimally, the system designer may vary the x-axis and y-axis scales as displayed on download grid  253  independently. 
     FIG. 2C shows download icons  257  deployed by the system on download grid  253 . The system creates a download icon  257  for each playback icon  205  placed on playback score  201  by the system designer (as illustrated in FIG. 2A) in orchestrating a multimedia presentation. The systems first identifies and fixes the topographical area of each download icon  257  in view of the x- and y-scales selected for download grid  253 . The system accomplishes this by analyzing each media object&#39;s data size, and then determining and assigning the topographical area corresponding to that data size on the currently selected x- and y-scales of grid  253 . 
     With further reference to FIG. 2C, pipe  255  is disposed on download grid  253  as a pair of lines running parallel to the x-axis and separating an amount of bandwidth selected by the system designer. Advantageously, any amount of bandwidth is selectable to be contained in pipe  255 . Pipe  255  thus represents a bandwidth constraint in the execution of the Playback Script. 
     With continuing reference to FIG. 2C, the system further automatically deploys download icons  257  within pipe  255 . As previously noted, as download icon  257  is displayed for each media object represented by a playback icon  205  displayed on the playback score  201 . Thus, when a system designer deploys a playback icon  205  on playback grid  203  as part of orchestrating a script, the present invention deploys a corresponding download icon  257  on download grid  253  within pipe  255 . 
     As the system designer adds, drops and manipulates playback icons  205  on playback grid  203  to orchestrate a Playback Script, the present invention arranges the display of download icons  257  within pipe  255  according to predetermined delivery rules. These rules include: 
     (a) download icons  257  must stay topographically within the confines of pipe  255  (i.e. must not “overhang”); 
     (b) download icons  257  must not “overlap” topographically within pipe  255 ; 
     (c) delivery of data must keep up with demand (i.e. the portion of a download icon  257 &#39;s topographical area displayed prior to any moment in time on the x-axis of download grid  253  must represent at least the amount of data within the corresponding media object needed by the Playback Script at that same moment in time); and 
     (d) as far as is topographically possible, all vacant space in pipe  255  must be occupied by justifying and packing download icons  257  within pipe  255  starting from timebase zero (i.e. from the left as shown on FIG.  2 C). 
     In this way, as the system designer manipulates playback icons  203  on playback grid  203 , the present invention topographically “fills up” pipe  255  by packing and left-justifying it with download icons  257 . It will be appreciated that the present invention thereby creates a Download Script that is a companion to the Playback Script, in which available bandwidth is optimized while satisfying the information needs of the Playback Script. 
     Advantageously, the system initially deploys download icons  257  within pipe  255  as rectangular shapes. As the system designer adds information to the Playback Script with more complexity, however, the present invention adapts the rectangular shapes as required into other shapes to fit download icons  257  together within pipe  255  according to the delivery rules. 
     With further reference to FIG. 2C, a preferred embodiment of the present invention is further disposed to adapt the displays of download icons  257  into any rectangular or square-aided polygonal shape to enable optimal “filling up” of pipe  255  according to the delivery rules. In this way, the present invention advantageously adapts download icons  257  of correctly scaled topographical areas into just about any square-sided polygonal arrangement to meet the delivery rules. Although not illustrated, it will be further understood that the present invention is not limited, however, to displaying download icons  257  in square-sided polygonal shapes. Consistent with the present invention, any shaped download icon  257  (including shapes with trapezoidal features or curved lines) may be created to enclose a correctly scaled topographical area to be deployed in pipe  255  in combination with other download icons  257 . 
     The present invention&#39;s deployment of static download icons  257  (such as graphic icon  258  on FIG. 2C) on download wore  251  deserves special mention. It will be understood that in typical multimedia presentations, “dynamic media objects” (such as audio or video) have a dynamic real time play length, whereas “static media objects” (such as graphics) are displayed statically for a preselected time. It will, therefore, be appreciated that static media objects such as graphics are advantageously deployed in a multimedia presentation as quickly as possible, so that the image appears rapidly. 
     In a preferred embodiment, an initial default deployment rule is followed wherein the system initially deploys static download icons on download store  251  to download fully within 50% of their corresponding playback time on playback score  201  on FIG.  2 A. This is reflected in the start and stop times in the deployment of graphic icon  258  on download grid  253  on FIG.  2 C. Note that 50% is an exemplary value, and ideally is a designer-selectable parameter for different types or sizes of static media objects. 
     Once the system has initially deployed such static download icons  257  on download score  251  according to the “50% rule,” the system then attempts to maintain the 50% rule while increasing numbers of download icons  257  compete for space within pipe  255 . 
     The system&#39;s inability to maintain the 50% rule for static download icons  257  does not, however, in a preferred embodiment, create an error condition in and of itself. Instead, with reference now to FIG. 2A, it will be seen that static playback icons  205  also each have a marker  207  along the time-based x-axis. Markers  207  indicate a “minimum clarity point” in the delivery of corresponding download icons  257  on download score  251  (see FIG.  2 C). Markers  207  are automatically generated by the system. The “minimum clarity point” is a designer-selectable percentage of data in the media object which, when displayed on runtime view  231  on FIG. 2B, will make the media object appear acceptably intelligible to the viewer. The “minimum clarity point” may, of course, be up to 100%, if the system designer determines that a “partial” display of the corresponding media object, such as a blurry image, is undesirable. Markers  207  on playback icons  205  on FIG. 2A indicate, during the playback period of static media objects, when the “minimum clarity point” will be reached according to the current Download Script. If the designer sees on playback score  201  that a marker  207  is unacceptably late in the display of a particular static media object, he or she may wish to adapt the Playback Script to enable delivery of the static media objects faster, causing marker  207  to be displayed earlier in time on playback score  201 . 
     Although, as described above, in a preferred embodiment the present invention automatically updates the arrangement of download icons  257  on download score  251  responsive to changes by the system designer in playback score  201 , this does not mean that the system designer may not take advantage of information displayed on download score  251  when making choices in orchestrating playback score  201 . For instance, the system designer may see that at a particular point in the download schedule, the arrival of media objects is so far ahead of the playback schedule that it would be advantageous to introduce additional objects into the playback schedule to make playback more information-rich. Alternatively, the system designer, may encounter heavy demand for media objects at a particular point in the download schedule, where such demand may be eased by “preloading” a media object earlier in the schedule, at a time when there is less demand. Such “preloading” may even be accomplished in a previous playback schedule when the system designer knows that the preloaded media object is going to be required in a later playback schedule. 
     As the system designer continues to make the Playback Script more data-rich, the invention continues to fill up bandwidth on download score  251 . Eventually, however, if the designer continues to make the Playback Script increasingly data-rich, an error condition will occur where the system is unable to fit all download icons  257  inside pipe  255  on the download score without breaking a delivery rule. Such a condition usually occurs in the presence of a “starving” error (where delivery in one or media objects on the Download Script cannot keep up with demand for that data on the Playback Script). The error condition may also occur in a situation where the system designer takes a Playback Script deliverable within a first bandwidth and then reduces the size of pipe  255  to a second, lower bandwidth. 
     Whenever a system designer creates an error condition in which a delivery rule is broken, the present invention alerts the designer of this condition. Advantageously, the alert includes a visible alert of the error condition on both playback and download scores  201  and  251 , as well as an optional audible alert (e.g. “bong”). The system designer preferably has the capability to disable the audible alert if so desired. The visible alert is preferably by highlighting icons  205  and  257  causing the error condition via, for example, shading or alternate coloring of the icons in error. Different visible or audible alerts may correspond to different error conditions. 
     FIG. 2D depicts download score  251  with download icon  257 H highlighted as in error. In the example of FIG. 2D, the media object represented by icon  257 H (“Music  2 ”) is unable to be delivered in time for demand for it on the Playback Script. 
     In response to an error condition to which he/she is alerted, the system designer must then either relax the bandwidth constraint by making pipe  255  wider, or take one or more corrective actions on playback score  201 . Such corrective actions may include a combination of the following: 
     (a) altering the Playback Script to reduce demand for data at critical periods (e.g. play data-rich media objects slower and/or later); 
     (b) changing the content characteristics of one or more media objects, such as substituting in a less data-rich media object (e.g. text for a graphic, midi music for “wav” music), or degrading the data-richness of the media object (e.g., reducing the sampling rate in a “wav” sound file); or 
     (f) delaying the start of the whole script by a small time period to allow more time for media objects to “preload”. 
     Depending on the corrective actions taken by the system designer on playback score  201 , the system makes corresponding adjustments to download icons  257  as currently deployed on the download score. Deleting a playback icon  205  from playback score  201  causes the system to remove the corresponding download icon  257  from download were  251 . Adding a playback icon  205  causes the system to deploy a new corresponding download icon  257  on download score  251 . The system then automatically, arranges the new icon  257  with other download icon  257  within pipe  255  so that the Download Script, now including the new icon  257 , continues to comply with the delivery rules. Moving the start time or end time of a playback icon  205  on playback score  251  causes the system to adjust the arrangement of the corresponding download icon  257  within pipe  255 , if necessary, to ensure continued compliance with the delivery rules. Altering the content of a media object causes the system to first recalculate and reassign the topographical area now representing the new data size of the media object. The system then adjusts the topographical area of the corresponding download, icon  257  on download score  251  by cutting or adding area at the “end-of-delivery boundary”. It will be appreciated that as used in this disclosure, “end-of-delivery” boundary means the boundary of a download icon  257  running perpendicular to the x-axis on grid  253 , and that defines a time on the x-axis when the delivery of the media object represented by that icon is complete. Exemplary end-of-delivery boundaries  259  are illustrated on FIG.  2 C. 
     Alternatively, in a second preferred embodiment, the system takes automatic corrective action when a delivery rule is broken. In this embodiment, the system automatically degrades the content of selected media objects by a preselected amount whenever the Download Script cannot keep up with the Playback Script. The action of degrading reduces the data size of the media object, and therefore its corresponding topographical area as deployed on download score  251  within pipe  255 . Sufficient selective degradation (with corresponding topographical area reduction) should eventually allow all download icons  257  to be arranged within pipe  255  on download score  251 . 
     It will be understood that degrading the media object is typically accomplished by compression or resampling techniques. The invention is not limited, however, to compression or resampling a the only methods of degrading a media object. 
     In this second embodiment in which the system automatically degrades media objects to reduce their data size, the system may also offer various options to the system designer in customizing the conditions under which such automatic degradation is to occur. Such options include: 
     (a) Only a highlighted object is degraded, or all objects are degraded, or selected objects are degraded; 
     (b). Degradation of objects is in preselected increments on an individual basis, or on a group basis; and 
     (c) Degradation is in a preselected sequence of objects. 
     It win be appreciated that methods known in the art can be used to accumulate the designer&#39;s choices in creating the conditions governing the selective degradation of media objects. Such methods include building tables whose parameters are referred to during the automatic degradation process. 
     The application of the present invention to the design of UDTs, as disclosed in the UDT Invention, will now be appreciated. Separate UDTs may be designed where Playback Script  201  enables the information exchange of the corresponding TT according to different delivery bandwidth ranges. For example, where delivery bandwidth is measured in the range, say, above 24 kbps, a UDT may be associated with the TT having a Playback Script whose information richness requires delivery bandwidth of 24 kbps or less. Where the delivery bandwidth is measured below 24 kbps, but above, say 8 kbps, a second UDT may be associated with the TT where the information richness of the playback requires delivery bandwidth of at least 8 kbps. It will be understood that, at the discretion of the system designer, there may also come a point in the bandwidth spectrum where the measured bandwidth is so low that the media objects are not worth delivering. 
     The foregoing selection of 24 kbps and 8 kbps as “cutoff” bandwidths are exemplary only. Ideally, an advantageous “cutoff” might occur when bandwidth becomes sufficiently low for a media object in a Playback Script to be required to be dropped rather than rescheduled or substituted. Other conditions, however, may also serve as thresholds to form “cutoff” bandwidths where a different UDT might be associated with a TT. 
     It will be understood that once the system designer is satisfied with a particular combination of playback and associated download schedules, the present invention then memorializes the download schedule as, for example, a job execution rile. This execution file may be used subsequently to control the delivery of media objects according to the download schedule. 
     Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.