|
Appendix A
In this chapter the media items and operators provided in the evaluation version are described.
A-1 Basic Media Items
Illustration A-1 shows four basic media items, which can be used in multimedia documents.
|
|
|
Illustration A - 1: Basic media items of a multimedia presentation
|
Further media items are shown in illustration A-2.
|
|
|
Illustration A - 2: Further media items
|
A-2 Timeline
A timeline is the most simple concept to define a temporal relationship between two media items. For each media item it is specified, on which point of time and for how long it has to be displayed. The relationship two media items have to each other is not a direct one but arranged indirectly using a timeline.
|
|
|
Illustration A - 3: Operators for the specification of the temporal
behaviour of media items basing on points of time
|
A-3 Interval Operators
Interval operators are an alternative approach to a timeline. They can be used to determine the temporal arrangement of media items. An interval is the duration of a media item is played out. With these operators, relations between the play-out intervals of two media items can be defined. The before operator specifies that the source media items is played out before the destination media item. The while operator specifies that they are presented in parallel.
|
|
|
Illustration A - 4: Operators for the specification of the
temporal behaviour of media items basing on intervals
|
A-4 Absolute Positioning
By means of the "absolute-positioning-operators" it is possible to position media items in a coordinate system, whose origin is in the left upper corner of the presentation area. Spatial statements have to be made in pixels. The setPositionLL operator, uses a coordinate system whose origin is in the lower left of the presentation area, that is the reason for the two "L"s in the operator's name. The other setPosition operators are interpreted in the same way.
|
|
|
Illustration A - 5: Operators for the absolute Positioning
of media Items
|
A-5 Relative Positioning
By means of the "relative-positioning-operators" it is possible to position media items relatively to each other. To understand the meaning of the arrangement, it is important to read at first the source item, then the operator, and at last the target item. "Image above video" for instance means that the image has to be displayed (spatially) above the video. It is necessary to define either a spacing or a position. Spatial statements have to be made in pixels. Thus the above operator can be completed by defining a spacing between the video and the image.
|
|
|
Illustration A - 6: Operators for the relative positioning
of media items
|
A-6 Interactive Presentations
The idea the concept of interactive presentations is based on the fact that the presentation can be divided into several scenes. For that purpose a "scene" container is used. By means of the "start" operator it can be determined, which scene the beginning of the presentation is. The "next" operator is used in order to determine the sequence of the scenes.
|
|
|
Illustration A - 7: Containers and operators for the
structuring of presentations
|
By using the "InteractionScene" container it is possible to specify scenes, whose presentation time is terminated by a user interaction. An interaction is for example a button click. Buttons are specified using a "button" container. In order to determine the scene invoked by the interaction, the interaction scene has to be connected with all scenes which can be subsequent to it. Finally, one of the subsequent scenes can be chosen for the property "InteractionScene". The "default" operator can be used to define the default behavior of the presentation in case no interaction takes place and the presentation time of the "InteractionScene" ends.
|
|
|
Illustration A - 8: Containers and Operators for interactive
Presentations
|
A-7 Computer based Training
Media items, containers and operators from the application area "computer based training" extend the interactive functionality of a presentation by the ability to specify questions and to continue the presentation depending on the answer of a user.
|
|
|
Illustration A - 9: Media items and containers for the
computer based training
|
The operators "false" and "correct" can be used to define, how the presentation has to be continued in case a question is answered wrongly or correctly. The "random" operator selects a subsequent scene by chance. The "solution" operator determines, which check box has to be selected in order to answer a question correctly. The "compare" operator can be used to check the correctness of an answer inserted into a text field.
|
|
|
Illustration A - 10: Operators for a computer based training
|
A-8 Interactive Travel Guide
The concept of a interactive travel guide is based on the assumption, that several sights are located in the same area. If the user approaches an object of interest, the presentation reacts by displaying information on the object. The area is represented by the location-area container and the object of interest by a location container. A "location" container has to be placed within a "location-area" container. The "default" operator defined a location which will be displayed in case the user is not close enough to any sight. By means of the "setLocation" operator it is possible to define, which position the sight has. The "rectangle" operator and "circle" operator define the size of the area which surrounds the sight.
|
|
|
Illustration A - 11: Operators and containers for an interactive travel guide
|
|
