With the continuing advances in multimedia technology, multiple sensory elements can easily be incorporated into classroom presentations as a means of enhancing the learning experience. I find two approaches extremely useful in creating content for various classes: creating Quicktime movies, and linking audio CD timing points to onscreen animations. For the creation of Quicktime movies, I use Strata Videoshop. I find it to be an extremely powerful program, but also one that is very easy to work with and designed with a very clear visual user interface. When working with audio CD’s, I find the frame-based structure of the Director platform to be very conducive to the real-time linking of different media types in a presentation organized in linear time.

CD Pro is a director Xtra developed by Penworks Corp, available for both the Windows and Macintosh platforms. It is designed to allow access to, and control of, CD audio devices from Lingo, enabling developers to add CD quality sound to projects without the high overhead for memory that digital audio requires. The CD Pro Xtra provides commands for accessing directory information such as the number of tracks, track lengths, total CD length, as well as all the necessary play commands including getting and setting the current position, looping, and status checking.

The first step in this process is to import media into the Videoshop program.

Elements are imported into the Bin by clicking on the open folder icon near the upper left corner of the window. The Bin (Figure 1) actually stores links to the original files rather than the files themselves. In the example above, I have imported both PICT files and an aiff file. The PICT files include 10 different files that will create a formal diagram of the music, and 8 PICT files consisting of the individual staves of the musical score. The aiff file is the audio file. This file is actually a MIDI file that has been translated to digital audio using the QuickTime Player. When the PICT files are imported, they are translated to a Quicktime format, but still function as graphic images.

Step 2: Placement on tracks

The window in Figure 2 is the sequence window. This is where elements are arranged in linear time with a resolution of 1/30^th of a second.

This example contains one sound track (on top) and two video tracks. Media elements are dragged from the Bin and placed in the appropriate track. Once the sound file is placed in the sound track, the timing indicators appear that allow for the synchronization of video and audio elements. Each PICT file can now be placed in one of the video tracks at any timing point. This is one of the important flexible aspects of the program. The starting point of any element can be placed at any open position on the time line within its track. The ending point can then be placed at any position greater than the starting position. In the above example, the top track is the sound track, the bottom track contains the animated diagram, and the middle track contains the scrolling musical score. Note that the first stave of the score doesn’t start until almost 7 seconds into project.

Step 3: Arrange on the canvas:

As elements are placed in video tracks in the sequence window, they are also placed on the canvas.

Figure 3. The Canvas.

In the above example, the bottom of the canvas window contains the empty formal diagram. When elements are placed in video tracks, they are automatically placed in the upper left of the canvas window. From there, they can be dragged to any position on the canvas. In this example, the musical score will be placed in the upper portion of the window. It is at the point that each element appears on the canvas that they can be easily adjusted to create as smooth an animation as possible, or adjusted for any desired effect.

Step 4: Save as a Quicktime Movie

Once all this is complete, the project can be saved as a quicktime movie, which can then be imported into several different presentation formats. The only consideration left is whether or not to use any sort of compression algorithm. The answer to this question really depends on how the final product will be presented.

The first step in this process is to create the appropriate media elements and import them into the Director cast. For this project, I’ve created PICT files of each stave of the musical score, and created a diagram that gradually fills in, illustrating some of the formal connections in the piece.

Step 2: Organizing media elements in the Director score and placement on the stage.

In the above example, the musical score elements are contained in sprite channel 4 and the diagram elements are contained in sprite channel 5. Note that each element lasts for at least three frames (the circle indicates the starting point and the vertical rectangle indicates the ending point). These elements usually need to last for at least three frames in order to account for overlaps between the score and the diagram. When these elements are placed in the score, they are also placed on the stage (similar to the canvas mentioned earlier). This is where the visual presentation is arranged in order to make the change from one visual element to the next as seamless as possible.

The script channel (just above the frame numbers in the above score) contains each of the scripts for the individual frames. It is these scripts that control the flow of the visual elements in relation to the musical material.

Step 3: Set timing points in the script channel in each frame where a change of graphics occurs. A typical frame script would be as follows:

This script says that when the playback head leaves the current frame, check the CD status and get its current position. If the CD is playing, then if its current position is greater than 51 seconds, move on to the next frame, otherwise stay in the current frame (go to the frame). The timing point (02:00:51:05) is read as track 2, 0 minutes, 51 seconds, and 5 frames (5/75ths of a second). If it moves on to the next frame, a change of graphics will occur. By identifying each timing point at which a change should occur, the visual presentation on the stage will be synchronized with the musical excerpt. In this case, the onscreen score will change from one stave to the next.

To obtain access to the CD drive, it must be initialized in the on StartMovie script:

The on startMovie script printed above starts out by establishing the global variable "cd" and then setting its value to the CD Pro Xtra. Throughout the director file, this global variable is used to access information about the audio CD, including setting its position and indicating where it should stop playing.

Since the CD Pro Xtra contains commands to access timing points to 1/75^th of a second, more complex scripts can be written (for starting and stopping at any point within the musical excerpt) that allow the sound and visual elements to be perfectly synchronized.

In comparing the two approaches presented above, both result in very useful content for class presentation, and both present some concerns that are worth noting. The most notable concern when creating a Quicktime movie is the size of the resulting file. When using digital audio and a large number of graphic elements, the file can become relatively large very quickly. This is where various compression schemes become important. If you need to compress a file, it might be necessary to experiment with a few different compression formats in order to find one with the correct balance between file size and video quality. The placement of each graphic element at the correct point in the music is actually fairly easy because of the time-based structure of the sequence window. In Director, the file sizes are quite small because the audio materials are played directly from the CD. One of the most time consuming tasks is to establish all the necessary timing points. With a relatively complex animation, it can take quite a while just to identify all of the timing points on the CD and then script each one in the appropriate frame.

Both of these approaches produce the desired results, and both are capable of delivering materials that can enhance the learning environment and engage multiple senses in the learning process. The net result is, I believe, a more informed student that is actively involved in the learning process.