The author is here defined as the creator of the program or file which is then utilized by the user. The author puts the file on a server computer, and the user accesses the file on a client computer which is connected to the server in some way, most likely via the internet.
Computer programs such as word processors, web browsers, and operating systems are often designed with smaller programs in self-contained modules which can be added on easily. For instance, the MacIntosh operating system has system extensions and control panels, Director has Xtras, and Netscape has plug-ins, called helpers in the Preferences menu. These modules, put in an appointed folder, can be called upon when necessary to run certain parts of the program or to recognize and run related types of programs. Procedures made available by Xtras are called X-commands (Xcmd), and other names beginning with "X." Netscape's plug-ins allow it to recognize file types, called Mime (Multipurpose Internet Mail Extensions) types, that are sent over the internet. Director's web plug-in for Netscape is called Shockwave.
Web browsers are programs designed to recognize and display different types of files, particularly Mime (Multipurpose Internet Mail Extensions) types, which are sent over the internet. Netscape Navigator is a well-known browser, that can display text, images, and animations written in different codes, such as HTML (Hypertext Markup Language). Browsers can be extended by plug-ins when new codes are introduced.
Computer-aided Instruction (CAI) programs have developed along with personal computers. Some existing programs are MacGamut, Practica Musica.
Hypercard is a MacIntosh program using a stack of cards as the metaphor. The best known examples of its use are found in the studies of works such as Stravinksy's Rite of Spring and Beethoven's Ninth Symphony, as well as the more recent Ragtime, put out by the Voyager Company. For recent examples of teaching uses, see the article by Elizabeth West Marvin and Alexander R. Brinkman in this issue of MTO. See also the Voyager web site and accompanying software, CDLink, which allows for Hypercard Stacks online.
For some Web pages designed for interactive
activities and teaching, see the following URLs: http://sparky.parmly.luc.edu/sharc for Greg Sandell's
timbre research, , as well as http://locutus.esm.rochester.edu/~cscotto/jrt121/
by my colleague, Ciro Scotto, as well as my own http://locutus.esm.rochester.edu/~dhlm/acoustics/acoustics.html.
In the past on the Internet, a sound or other file had to download completely and then begin playing, which can take a lengthy period of time. Streaming files are created with enough control information put at the beginning of the file so that the file can be processed and begin playing or presenting almost immediately. The remainder of the file continues to download into a buffer simultaneously. The problem is that download times are unpredictable on the Web and may change even during one file's download. Thus, a sound may begin playing, then stop, while enough information flows into the buffer to continue the play. Director's streaming audio allows authors to set the initial time before the playing begins (default 5 seconds), which allows some leeway, but there is no fail-safe solution.
Soundwaves can be described digitally in a Cartesian graph type format, with x-values as time, measured in small chunks called samples. Samples of sounds are taken in fractions of seconds, usually in 1/22050 or 1/44100's of a second, or 44,100 samples = 44,100 times a second. The sample rate is twice the highest frequency possible in the sound represented, thus 44,100 samples per second allows for a frequency of 22050 Hz, or cycles per second, above most people's range of hearing; 22050 samples per second allows for 11025 Hz frequencies, within the range of hearing, but is acceptable as a compromise (the piano spans 27.4 - 4186 Hz). Computers store information in binary numbers, with each bit set to either 0 or 1, and in bytes of 8-bits each to store numbers or words, etc: 8-bits = 1 byte, 16 bit = 2 bytes. A kilobit (Kb) = 1000 bits, a Kilobyte (KB) = 1000 bytes, a Megabyte (MB) = 1,000,000 bytes. In the Cartesian graph representation of a soundfile, y-values are the amplitude levels, measured in divisions relating to the "bits" present in the sound representation, usually 8 bits (=256 levels) or 16 bits (=16536 levels). The sound wave is much more faithfully reproduced by the many more levels in 16 bits, but for size reasons 8-bit sound has been used on the Web. The size of sound files (uncompressed) depends on the bits and samples: 8 bits = 1 byte, so that 8 bit, 22050 sample sound takes about 22 KB per second; CD quality stereo 16 bit, 44,100 sample sound takes 2 * 2 * 44,100 = about 166.4 KB per second.
An Analog-to-Digital converter converts a sound signal (trumpet note, traffic noise) from its electrical representation into a series of numbers representing the time and amplitude values of the signal. A Digital-to-Analog converter reverses the process, creating sound from a series of binary numbers.
Midi file information can be found
but there are thousands of sites with MIDI files and info.
Information and downloads related to Quicktime
2.5 can be found at: http://quicktime.apple.com
Mod file information can be found at: http://members.aol.com/Edgeman101/musica.html
Although useful by itself, Director may also be ordered in a "Studio," bundled with a sound editing program, SoundEdit 16, an image editor, xRes 3, and a 3D tool, Extreme 3D 2, for a complete multimedia package.
In the original CD-ROM version of this movie, the sound is a quicktime movie, and can be accessed at any point, as well as stopped, started, and paused. Director's streaming audio unfortunately only allows for the latter. Return
Director has a few quirks that should be noted.
First, the first frame of a movie often doesn't work properly when sounds or scripts are present, and it is best to begin in frame 2, leaving frame 1 either empty, or with the same stage as frame 2 without the sounds, scripts, or markers, so that the movie begins and passes through at least one unscripted frame before the action begins. Second, the last frame of a movie needs to be considered carefully, otherwise the movie will just end; often, the "last" frame loops, waiting for a user click. Third, repeat loops and pauses shut out the user (and, in Web pages, the browser as well) and should be used carefully; options should be given to stop any lengthy activity. Fourth, when using text, use "field" cast members for general text but use a standard font, since client computers will only show fonts that they have mounted; for specific fonts or text arrangements, use "text" cast members, which are read as bitmaps. Fifth, when done making a movie, it is often convenient to get rid of unused Cast members by opening the Find command, which has a setting "not used in movie." The list of members includes movie and frame scripts however, which must be kept. It is thus best to name these scripts to avoid a tedious search to be sure which cast members may be deleted. There are also a few general quirks of computer programs to remember. For instance, when using linked media, make the link to a copy of the image or sound, etc., because any changes made within, in this case, Director, will change the source media.
In non-web uses, sounds can also be placed in the two sound channels; when the movie plays the frame with the sound file in it, it will play the sound file. To coordinate sound with animation, it is easier to import the sound as a quicktime movie; quicktime movies can be controlled virtually frame by frame, and so a quicktime movie sound can also be started and stopped and accessed at any point easily to coordinate with animation. Unfortunately, this is not yet possible with linked quicktime sounds or Director's streaming audio.
On servers, a file called "mime.type"
(UNIX) contains many file types; add the line: application/x-director dcr,
The standard system fonts: Arial, Courier
New, Symbol, Times New Roman, and Wingdings on Windows and Chicago, Courier,
Geneva, Helvetica, Monaco, New York, Palatino, Symbol, and Times on the
Macintosh. If you choose a standard Macintosh system font, Director automatically
substitutes a standard Windows system font when someone runs the movie on
a Windows computer--and vice versa.
For the best source on Director, go to http://www.macromedia.com, for music-related shockwave sites go to http://www.teleport.com/~arcana/shockwave; a few helpful books are: Gary Rosenzweig, The Comprehensive Guide to Lingo (Ventana, 1996), and Cathy Clarke, Lee Swearingen, and David K. Anderson, Shocking the Web (Berkeley, CA: Macromedia Press, 1997).