Level: This course is a senior Computer Science course intended primarily for CS majors. Thus you are expected to be proficient programmers, Web and Windows users, problem solvers and writers of English. You'll have to do all these things this semester.
Approach: We'll go for breadth, by talking and reading about lots of topics - ranging from encoding and encryption technologies, to user interface design principles from psychology. We'll also go for depth, by building a prototype of some serious piece of media technology. Some groups will be asked to work on specific projects, based on my estimates of your abilities; others may suggest their own projects. The default task for individuals or groups who are not chosen for specific efforts is to build an on-line commerce system.
Teaching Style. I will give specific assignments involving reading, net surfing, experiments, and expect you to fill out a questionnaire called a Query. Most class time will be spent discussing these queries. I will try to avoid lecturing unless absolutely necessary, because experience indicates that you learn more by reading and actively explaining your knowledge, than you do by listening.
You'll be working on your third projects in teams of four, more or less. If you hate teams, then participate in the design and arrange for a sub-section that you can build by yourself. If you have mitigating circumstances, I may allow you to work alone.
There's one very important Web site: www.amazon.com. This site is both the place from which you should order your PERL book, and an example of the kind of site I expect you to learn how to build during this course, for your third (default) lab project. The first two projects will be parts of the learning experience required to get to the point of building your masterpiece.
NOTE: The "merchandise" you will sell in your pseudo-store is up to you (but, hey, let's avoid porn and other things that could lose us our jobs, eh?) Part of the evaluation criteria will be based on how well your site incorporates novel, interesting, challenging media. So we'll be looking at sound, animation, and a variety of other tools that you can explore. You may build this site as a team, or as an individual, but teams often do better because they can include people with graphical and musical talents, as well as programming whizzes.
So, here's your first assignment (part 1), for catch-up purposes: READ CHAPTERS 1 and 2 of the Steinmetz and Nahrstedt text (henceforth called SN). To inform your reading, here are the questions you need to be able to answer by Thursday's class. These topics will also be covered in today's lecture. Write down the answers, because approximately six times during the fifteen weeks of this course, I'll suddenly ask you to hand in the answers. Having them in-hand at that time, is a factor in determining your grade for Participation.
Part 2: Read Chapter 3 (Audio), and check the Web site for Notes and Queries about it. I shall try fiercely to have them in place by noon on Wednesday.
Part 3: If you're gonna take this course, ORDER THE PERL BOOK TODAY!
QUERY #1 - Due Thursday 7 January 98 - the questions are all through these notes. Go find 'em!
1.1. The textbook is organized in three main components. What are they? Which one is on the bottom of Figure 1.1, and why?
The plural of medium is media. Blame the Greeks for that one.
1.2. Define a medium in your own words. Your definition should contain NONE of the words in the definition on page 9, and none of the words in the first paragraph on page 10. It will contain the same ideas, but you gotta work at finding new ways to say it. NOTE: A definition is not an example, and vice versa.
1.3. Give two examples of a medium, and two examples of something that is not a medium.
1.4. Consider the game MYST (or RIVEN, if you're up to date.) Tell me the perception, representation, presentation and storage media that are involved. Try not to skip any.
Some necessary explanations.
Representation spaces can be thought of as being containers, like an egg carton. A space has more than one location in it. A screen has pixels, an audio space has many places one can sit to hear the sound differently.
Representation values are the kinds of eggs that can be put into the carton, metaphorically speaking.
A representation dimension can be thought of as the "index of an array" - the sequence of integers or real numbers which provide ordering to the set of representation values. A picture is obviously a two dimensional representation space. Fun begins when we consider the third dimension as being time.
Some terminology about perceptions.
The author's version:
Discrete: composed of multiple separate (countable) pieces.
Continuous --> perceived as flowing without separate sequential chunks.
Time-independent --> can be read or used at any pace. A page of the textbook, or this Web page, for example.
All time-independent media are time-discrete, according to the author's definition. A book is a discrete medium. Should be processed as fast as possible by a computer/communication system, sez he.
Time-dependent --> only makes sense if perceived at the rate specified by the authors. Some time dependent data streams are discrete (e. g. mouse clicks, or keystrokes in a chat-room), and, some are continuous (e. g. streaming audio or video.)
Moshell's version:
Mathematically, "continuous" describes a function (e. g.) from real numbers to real numbers) in which there are no abrupt changes. An arbitrarily small change in the function's input (e. g. time) must produce an arbitrarily small change in its output. Speaking in terms of graphs with the input (x) horizontal, the output (y) vertical,we say that the graph never goes straight up.
By informal extension, a continuous set would be one in which every object has at least one near neighbor. Consider the real numbers between 0 and 1 as an example.
Discrete describes a set with members that can be counted, like marbles or people.
With regard to perception: discrete and continuous can apply to spatial
as well as temporal perceptions. If you can see the separate pixels, it's
discrete along the spatial dimension. A photograph appears continuous along
the spatial dimensions, because for any value of (x,y) there is a picture-point
color which does not differ enormously from the one next to it.
Author's definition of "multimedia":
Several prior terms are needed: "independence". The audio and video
on a videotape only make sense when presented synchronously, so they
aren't independent. So they aren't "multi" media.
"Computer controlled integration" means that a computer can be used to mix and match components in a "live" fashion. That is, the PRODUCT must retain interactivity. Thus, a word processor that allows insertion of pictures into text is not multimedia, because its product is passive. If changing the entry in a field also changes the picture, it's active.
"Communication" - information goes from one place to another.
Authors' definition of Multimedia, at last: See page 17 for the original.
A multimedia system has these features:
How Time Flows
Three terms are needed here. Asynchronous transmission means "whenever, but as fast as possible." e-mail is asynchronous, or asynch for short.
Synchronous transmission must occur within a maximum end-to-end delay constraint, but there is no minimum. Thus, sometimes big bursts of data arrive before they might be needed for continuous playback, and storage must be provided in the receiver. Internet telephone works like this.
Isochronous transmission must occur within both a maximum and minimum delay.Television is an example, as TV sets have no memory. The "jitter" (variation in end to end delay) is bounded.
Strongly periodic data streams consist of packets with constant time intervals between them.
Weakly periodic data streams consist of packets with time intervals which vary according to a cyclic function (e. g. NTSC video signals have 262.5 horizontal lines with retrace intervals, then one vertical retrace interval.)
Aperiodic data streams are everything else.
Strongly regular data streams have packets of constant size.
Weakly regular data streams ... well here's a query for you.
Query #1 continues:
1.5: Explain weakly regular and irregular data streams, using examples
of your own choosing.
Connected and Unconnected data streams. If it's a freight train, it's connected. If it's a bunch of trolley cars,it's unconnected. Get it?
Logical Data Units (LDU) are elements of the content of a media piece. Many levels of granularity exist. A symphony may have four movements; a movement may have 320 measures each consisting of four beats, or alternatively a movement might consist of 18.1 minutes of CD audio. LDUs are based on the "story being told", not on the underlying technology.
Protocol Data Units (PDU) are the packages of information as seen by the medium's technology. Much more on them later. Think of PDUs as the boxcars in the train. The train is (metaphorically) moving a house. The first car might have all of your front porch and part of the living room in it. Thus, PDUs don't always correspond to LDUs or even to parts of LDUs.
END OF CHAPTER 2
Quest for Tools
One of the ways you will earn Participation credit is by volunteering for various Quests. In a Quest, a group or an individual takes a particular topic, goes to the Web or the library or the bookstore and learns some essential facts, then reports back to the class within a specified period of time. Here are the Standard Questions Version 1 (we'll think of more, as we go along.)
1. What does the product do?
2. How can we get it? (Cost, vendor, location, free betas, etc.)
3. Reviews by other than the maker: how good is it? What are its competitors?
4. URL where interested parties can get all the facts.
5. Your Recommendations: How badly do we need it?
Your report will include a concise Web page which you build, containing
a writeup with links to the above information in a clear format.
Here's the first two products for which someone or group can volunteer:
Microsoft Visual InterDev (product)
Microsoft Commerce Server
We'll provide plenty more products to be analyzed, as the semester goes
on. You are also free - and encouraged - to suggest products to me.
The following Questionnaire was handed out in paper form in class,
for Moshell's data gathering purposes.
Name_____________________
E-Mail Address__________________
Phone Nr (day) _______________(night)________________
Major, year (e. g. cs, senior.)_________________
On a scale from 1 (none) to 10 (I won the world championship), rate your skill in the following domains:
SOFTWARE
C programming __
C++ programming __
PERL programming __
Unix programming __
Windows programming __
Java programming __
Visual Basic programming __
Graphical programming __ (using what tools? OpenGL? VRML?)
TCP/IP and Sockets programming __
GRAPHICS
Skill at drawing with pencil and paper __
Experience with object oriented graphical software tools ___ (which
ones? rate each one.)
Experience with pixel-painting oriented tools __
Experience with Photoshop type image manipulation __
Experience with HTML and Web page construction __
DRAMA
I write stories or screenplays __
I write or perform dramatic works __
I am a Dungeons and Dragons dungeon-master or player __
MUSIC AND SOUND
I play a musical instrument (which one? Rating?) __
I have a MIDI system and know how to use it __
I know about Sound Blasters and Wav files and all that stuff __
I howl at the moon with my dog on weekends __
LEADERSHIP
I like to lead groups __
I am good at leading groups __
I have a small black moustache and like to hear people say "Heil!"
__
OTHER STUFF
What should you be telling us that would help your team find you?