I. Types of existing multimedia authoring tools

At present, the most popular multimedia creation tools are mainly divided into the following three categories.

1. Narrative language

The idea of developing works with such tools is to regard the development process of each title as a combination of books according to the structure of the book, and designate each picture as a page, each page can have multiple levels of objects. Set the contents of each page and the actions between them, and then design the work in the specified layout language. Among these tools, the representative one is the MultimediaToolBook tool of American Asymetrix Company, and its programming language is OPENSCRIPT. The biggest advantages of this kind of tools are flexible development, low price and easy acceptance for users who know a little about programming; The disadvantage is that the overall running speed is slow, although it is easy to get started, but it takes a lot of effort to master its mechanism, especially for accessing multimedia resources. OPENSCRIPT is mainly called by MCI function, and related calls must be explicitly written in the script. The syntax and order are not intuitive enough and lack of hints, which is enough to make non-programmers feel ashamed.

2. Interactive icon types

This kind of tool mainly allows users to arrange the required components directly on the screen, and define the actions of the components themselves and the relationships between the components. Its working way is to make multimedia works by visual method on microcomputer. By selecting simplified visual icons, a flowchart of the application structure is formed, and then the content is added to the structure. The flow chart defines the flow of multimedia elements. This tool is very suitable for users who have no programming experience, so an interactive multimedia system can be developed in a short time. Among these tools, the famous ones are authorware Professional developed by Authorware Company of America and Icon Author of AimTech Company of America. It is mainly used to develop event-driven education, training simulation and navigation systems that require high interactivity. The disadvantages of such tools are that they are usually expensive and their flexibility is limited by existing systems.

3. Time stream type

This kind of tool is more suitable for developing briefing system, and it has a strong time sequence in multimedia display, mainly based on graphic information. Well-known tools include action tools, PowerPoint, Harvard graphic tools and so on. These tools basically support multimedia information through OLE external means. Therefore, when playing multimedia, the disk I/O action is frequent, the system overhead is large, and the operation efficiency is low.

The running environments of the above three multimedia authoring tools are all based on Windows 3. X, the audio file formats that can be processed are wav and mid. Still image file formats include pcx, bmp, gif, tga, jpg, tif, wmf, dib, etc. There are avi, fli, flc and other dynamic image formats.

Second, the function and design method of the multimedia creation system Through the above analysis, we can see that the multimedia creation system generally has the following characteristics.

1. Getting started is easy, and there is no programming experience of professional programmers, but it is not easy to master it skillfully. Some specific simple requirements are often achieved through the use skills acquired after mastering them skillfully. In addition, it is not convenient to modify the content that requires high timeliness and is often modified.

2. Support a variety of hardware devices and a variety of file formats, and can generate complex products containing graphics, images, text, sound, animation and video elements.

3. It has the ability of process control and can provide a guiding framework for the above elements.

4. Although it includes graphic editing, dynamic editing, digital animation, video editing and other tools. The production ability of multimedia data is not as powerful and exquisite as that of special software.

At present, there are abundant special software resources for processing multimedia information, such as Wordfor Windows and WPS. Graphic images include PhotoStyler, Photoshop, CorelDraw, etc. Animation has Animator, 3DS and so on. There is a windy video in the video.

Ows, Adobe Premiere, Quicktime for Windows, etc. Sound system, WaveEdit, etc.

For users, they have mastered the special software for multimedia processing and have to learn the weak media processing tools in the creative system, which is a kind of repetition. Users require meticulous design of media materials, and media works are sensitive and efficient when broadcast. Therefore, our design principle is to use the existing powerful multimedia processing tools to combine system integration with software programming to shorten the development cycle and create the best software. Not only meet the general requirements, but also meet the specific requirements of users. This method combines the advantages of descriptive language and icon-based creative tools, and has the characteristics of strong system flexibility and expansibility, wide application range, clear user needs, saving software resources and so on, and overcomes the shortcomings of poor flexibility and system limitations of existing creative tools.

The main functions of each module of the designed multimedia creation system are as follows.

Text editing: This is a text editor, which inputs the original text to be played line by line to form a text file.

Script editing and integration: It provides a convenient, efficient and intuitive editing method for integrating graphics, text, sound and image data. According to the user's design requirements, it edits and integrates various media data to produce the effects of media objects (such as flashing, flying, rotating, fading in and out, size, positioning, etc.). ), and finally form a script file to be called during broadcasting.

Graphic image processing: PhotoShop or PhotoStyler software connects graphic images to process various bitmap files, including wmf, tif, bmp, pcx, tag, gif, dib, jpg and other formats; Statistical graphics provide methods for making various 2D and 3D statistical graphics.

Script broadcast: the script file formed after script editing and integration is directly transferred to broadcast, which can be broadcast in automatic broadcast mode or guided single-step control broadcast mode. You can control to pause and continue playing dynamic images.

2D animation processing: hook Animator 2D animation processing software processes and forms animation files in fli and flc formats.

Three-dimensional animation processing: hook up 3DS three-dimensional animation processing software, and make and form animation files in flc and fli formats.

Video processing: video connected to windows, QuickTime and Adobe Premiere software of Windows. Video images with general quality requirements are played by TV, VCR or DVD player, and processed by video capture card to form video files in avi and mov formats. For high-quality, full-screen video images, mpeg and dat image files are generated by special digital video sampling and compression tools and stored in optical disks. When playing, MPEG video decompression card is used to retrieve image files from the CD and decompress them in real time to meet the visual requirements of full screen, full motion and full color.