A   S t r e a m i n g   M e d i a   P r i m e r :  

G L O S S A R Y

digital rights management (DRM): Server software 

 streaming,  Flash does not fi t  the  defi nition  of  true 

that protects against the illegal distribution (a.k.a. 

streaming  used in this Primer. While Flash shares 

pirating) of copyrighted content over the Internet. 

some characteristics with streaming media, and can 

digitizing:  Act of converting an analog audio or video 

simulate video by animating sequential frames, it does 

signal to digital information.

not deliver standard, full motion video fi le  formats 

over the Web and is constrained to fi les containing no 

download: The act of one computer requesting and 

more than 16,000 frames (approximately 17 minutes of 

receiving data, via a network, from another computer.

material at 15 fps). The Flash fi le format, SWF, can be 

downloadable media:  Media  (i.e., video and/or 

created using Adobe After Effects and Adobe GoLive 

audio) that can be downloaded and written to disk 

software, as well as other applications.

(i.e., saved onto a computer hard drive); typically refers 

FPS: Number of  frames per second;  a method for 

to media fi les hosted on a Web server (as opposed to 

describing frame rate.

a media server) which can, and often must, be entirely 

downloaded and written to disk in order to be played 

frame: A single still image in a sequence of images 

(as contrasted to streaming media).

which, when displayed in rapid succession, creates the 

illusion of motion the more frames per second (FPS), 

DV: Generally refers to a digital  video format that 

the smoother the motion appears.

incorporates DV compression, the type of compression 

used by DV systems or by a DV camcorder that employs 

frame rate:  The number of images (video frames) 

the DV format. A standard consumer DV camcorder 

shown within a specifi ed time period; often represented 

uses mini DV tape, compresses the video using the 

as  FPS (frames per second). A complete NTSC TV 

DV25 standard, and has an IEEE 1394 port for connect 

picture consisting of two fi elds, a total scanning of all 

ing to a desktop computer. The DV designation is also 

525 lines of the raster area, occurs every 1/30 of a 

used to for a special type of tape cartridge used in DV 

second. In countries where PAL and SECAM are the 

camcorders and DV tape decks.

video standard, a frame consists of 625 lines at 25 

frames/sec.

DV25: The most common form of DV compression, 

using a fi xed data rate of 25 megabits/sec.

FTP:

File Transfer Protocol is the simplest way to 

exchange  fi les between computers on the Internet. 

dynamic media: Refers to design elements that incor 

Like the Hypertext Transfer Protocol (HTTP), which 

porate motion and/or sound such as video, animation, 

transfers displayable Web pages and related fi les, and the 

and audio.

Simple Mail Transfer Protocol (SMTP), which transfers 

effect: Distortion of a frame or frames of video to 

e mail, FTP uses the Internet's TCP/IP protocols.FTP is 

change its appearance; distortion of audio to alter the 

commonly used to transfer Web page fi les from the on 

quality of sound.

which they were created to a Web server. 

encoder: A software application or a device (hard 

hinted movie:

  T

erm used in Apple's QuickTime 

ware) used to encode i.e., compress and format (see 

architecture for video fi les that are formatted for true 

encoding) digital video or audio.

streaming.

encoding: Encoding accomplishes two main objec 

hint track: Term used in Apple's QuickTime archi 

tives: 1) it reduces the size of your video and audio fi les, 

tecture for the set of streaming instructions which, in 

by means of compression, making Internet delivery 

the QuickTime streaming format, are embedded right 

feasible, and 2) it saves your fi les in a format that 

into the movie. Other architectures provide streaming 

can be read and played back on the desktops of your 

instructions as metafi les which are often downloaded 

targeted audience. Some encoding solutions may also be 

separately from the actual movie fi le.

confi gured to provide additional processing functions, 

such as digital watermarking, for example. Encoding 

host:  A computer system providing data to be accessed 

may be handled by a software application, or by special 

by a user working on a remote system, via a network 

ized hardware with encoding software built in. Note 

such as the Internet; can be a synonym for server. The 

that the term compression is often used interchangeably 

term  host  is also used to refer to businesses that pro 

with the term  encoding  when referring to the fi nal 

vide such systems. A hosting services provider (HSP) 

step in preparing media fi les for Web distribution; but 

is an application service provider (ASP) dedicated to 

compression is only a part of the encoding process.

providing hosting services.  A hosting services provider 

typically operates a Web server farm, at a data center or 

fast start streaming: Term used in Apple's QuickTime 

co location facility. The term  host  may also be used 

architecture for progressive download.

as a verb, as in  to host  fi les on a server.

fi elds: The sets of upper (odd) and lower (even) 

HTML: Hypertext Markup Language is a lexicon of 

lines drawn by the electron gun when illuminating the 

formatting commands typically used to create Web 

phosphors on the inside of a standard television screen, 

namic Media

pages. HTML is the language that describes all the basic 

y

thereby resulting in displaying an interlaced image. 

elements of a page (such as text and graphics), but 

In the NTSC standard, one complete vertical scan 

its current incarnation can't do much to make a page 

of the picture or  fi eld contains 262.5 lines. Two 

interactive; Java and ActiveX are often used to build 

fi elds make up a complete television frame the lines 

interactivity into Web pages.

of  fi eld 1 are vertically interlaced with fi eld 2 for 525 

obe D

lines of resolution.

HTTP: HyperText Transfer Protocol is comprises the 

d

underlying set of rules used by the World Wide Web 

FireWire: The Apple Computer trade name for 

A

to defi ne how messages are formatted and transmitted, 

IEEE 1394.

and to communicate what actions Web servers and 

Flash: Macromedia Flash is a popular architecture 

browsers should take in response to various commands. 

44

for vector based Web animation. Often referred to as 

For example, when a URL is specifi ed in a browser, an