Glossary
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A
AAC
AAC is a compressed audio format similar to the MP3 format frequently used for podcasts. The AAC format can be used to create enhanced audio files that contain slides, chapter marks, and hyperlinks. These enhanced files have the .m4a, .m4b, or .m4p file extension. Only a few media players can play AAC files; such as QuickTime, iTunes, WinAmp, and VLC.
Add-on
Software that is designed to enhance or expand the capabilities of other software. For example, iQfx would be considered an add-on to RealPlayer because it enhances audio quality.
ADSL
(Asymmetric Digital Subscriber Line). One type of Digital Subscriber Line technology, a high-speed transmission method that works over existing, twisted-pair copper wires. In this method, downstream rates are faster than upstream rates. Maximum speeds range from 1.544 Mbps to 8 Mbps, but can depend on your provider, line conditions and proximity to a telephone switching station.
Aggregator
Client software that uses a web feed to retrieve syndicated content such as podcasts and news. Also known as a feed reader.
AIFF
(Audio Interchange File Format) A file format that is used to store high-quality sampled audio and musical instrument (MIDI) information. AIFF files are similar to WAV files in both size and quality. Though AIFF files were originally created by Apple, audio programs on both the Mac and PC can usually read them.
Algorithm
A complex mathematical procedure or formula which seeks out repetitive data and replaces it with a code. More advanced algorithms take into consideration the limitations of human perception. The formula which determines how to compress and decompress data.
Amplifier
A network component, also known as a Repeater. Amplifiers increase the power of a signal when it is lost due to attenuation. They allow signals to cover greater distances in a LAN environment.
Authoring
The process of assembling a custom layout and operation of a media presentation. Authoring is most commonly referred to in the process of creating a video DVD; the footage is digitized, the menus and operation of the DVD are authored, then the DVD is mastered to a disc.
B
Backbone
A segment of a network that is higher speed than the rest of the network and connects other segments together.
Bandwidth
The amount of data that can be transmitted in a fixed amount of time. For digital devices, the bandwidth is usually expressed in bits per second or bytes per second. For analog devices, the bandwidth is expressed in cycles per second, or Hertz (Hz).
Bit
The unit of information. Short for "binary digit", a bit has either a value of 0 or 1 and is the smallest unit of measure of data in a computer. Eight bits make up 1 byte which can store one letter, number or symbol.
Bit Rate
The speed at which binary content is streamed, i.e., travels from one place to another on a computer network, such as the Internet. Bit rate is measured in kilobits per second (kbps). Thus, 28.8 Kbps modem, for example, can transmit or receive around 29,000 bits per second.
Bridge
A network component that connects two LANs, thus extending the range of the network. Bridges check data and forward them across LANs.
Broadband
Describes a high-speed (high bit rate) network connection (T-1, DSL, cable modem) as opposed to a dial-up connection. Also used to describe content which takes advantage of a high bit rate connection.
Broadcast
Simultaneous delivery of a presentation, whether live or prerecorded, in which all viewers (stations on a network) join the presentation in progress.
Browser
The program that finds and displays Web pages. Microsoft Internet Explorer and Netscape Navigator are browsers.
Buffer
Space allocated on a system’s Random Access Memory (RAM) where data is stored temporarily until it is transferred to another part of the system. In streaming applications, buffers store video or audio data until there is enough information for the stream to be composed.
Buffering
A process similar to caching, buffering pre-fills (expressed as a percentage) streaming media that is entering the user's computer at a faster rate than can be played, and saves the data as memory without backing up or overloading the Player. Most streaming media players buffer a small percentage of a streaming media presentation before beginning to play it. Buffering also may occur in the middle of a presentation, when available bandwidth does not match the presentation's required bandwidth.
Bus Topology
A LAN network structure in which all stations (nodes) are connected to the same cable. Data is transmitted up and down this single cable.
Bypass
Use of transmission facilities, usually for data, which avoid local telephone company networks.
Byte
Short for "binary term", a byte is a unit of memory made of eight bits, about the amount needed by a computer to store one typed number or letter. Consists of 8 bits.
C
Cable Modem
A device that allows an Internet connection via a cable TV line to provide high-speed Internet access through a cable television network. Speeds can top 1 Mbps. Cable modems are typically external devices that are placed next to your computer and connected via an Ethernet cable.
Cache
(Pronounced cash) The term for the computer memory that temporarily stores information that is most frequently used, as in often visited Internet sites. Usually stored in a special section of the main memory or in a separate device, this data can be retrieved much faster than if the computer has to find it on the hard drive. Caching can also refer to distributing Internet content to multiple servers that are periodically refreshed.
Capture
The process of changing or transferring digital or analog audio or video files to binary files which can then be edited and encoded. May be referred to as digitizing.
CBR
Constant Bit Rate (CBR) encoding is an encoding method that varies the quality level in order to ensure a consistent bit rate throughout an encoded file.
CDMA
Code Division Multiple Access - CDMA is a "spread spectrum" technology. This means that it spreads the information contained in a particular signal over a much greater bandwidth than the original signal. When implemented in a cellular telephone system, CDMA technology offers numerous benefits to the cellular operators.
CDMA2000 1x
CDMA2000 is synonymous with 3G pertaining to wireless networks. 1x is the first phrase of implementation of a 3G CDMA based cellular network and offers about twice the capacity of current existing 2G networks, with data transfer rates of 144kps. CDMA2000 1x is backwards compatible with existing CDMA networks, and sends and receives data in packets. It allows the data channel to be allocated to other users if there is no data being transmitted, and therefore makes the network more efficient.
CDN
Content Delivery Network - Companies that deliver Web data (including streaming media) via an intelligent distributed network. For companies providing streaming content delivery services, this means that audio or video streams will be delivered more reliably, with less buffering and time outs. Generally, this will provide a better overall experience for the end user.
Circuit Switching
A communications technology in which a dedicated channel (or circuit) is established for the duration of a transmission. The most common circuit-switching network is the telephone system, which links together wire segments to create a single unbroken line for each telephone call. Circuit-switching is ideal when data must be transmitted quickly and must arrive in the same order in which it's sent, for example live audio and video.
Client
A software application that receives data from a server. A Web browser is a client of a Web server. RealPlayer is typically a client of RealSystem Server.
Clip
A media file within a presentation.
Coaxial Cable
Copper cable that consists of a central wire surrounded by insulation and then a grounded shield of braided wire. Coaxial wire is widely used by the cable television and computer industries. It is less prone to interference than regular wire cables.
CODEC
(Coder/decoder). Standard method of compressing and decompressing data, typically done with audio/video files where data is encoded or compressed to reduce file size. A codec allows an operating system or a program to properly play audio or video in a particular format. Codecs can use software-only or hardware-assisted schemes. In converting data between uncompressed and compressed formats, codecs reduce the bandwidth a clip consumes.
Co-location
Presence of private company servers at the physical premises of an ISP, in order to utilize the ISP's high-speed connection and safety/backup features.
Component Video
Component video consists of three signals. The first is the luminance signal, which indicates brightness or black & white information that is contained in the original RGB signal. It is referred to as the "Y" component. The second and third signals are called "color difference" signals which indicate how much blue and red there is relative to luminance. The blue component is "B-Y" and the red component is "R-Y". The color difference signals are mathematical derivatives of the RGB signal.
Green doesn't need to be transmitted as a separate signal since it can be inferred from the "Y, B-Y, R-Y" combination. The display device knows how bright the image is from the Y component, and since it knows how much is blue and red, it figures the rest must be green so it fills it in.
Once we've got our video information packaged up in component video format we've reduced bandwidth requirements by a factor of 3 to 2.
Composite Video
A type of video signal in which all information—the red, blue, and green signals (and sometimes audio signals as well)—are mixed together. This is the type of signal used by televisions in the United States.
Compression
The reduction in the size of data in order to reduce file size and speed up transmission time. Compression is performed by a program which uses an algorithm or formula to determine how best to compress and decompress the data. This can be done using hardware, software or a combination of both. Compressed media files are then decompressed on the user's end, thus allowing for faster and more efficient downloading.
Information in the form of words, numbers, or images that has been transcribed into bits. The information can then be read by a computer and stored as memory or sent over the Internet.
The rate at which bits of information are transmitted per second.
(Media Type) File format that travels across the RealSystem architecture to RealPlayers.
A collection of data.
To use for an intended purpose or end. For example, when the Real Broadcast Network (RBN) is stated as having the largest deployment of RealSystem G2, this means RBN utilizes more of this technology on its network than anyone else.
When computer devices hook up to a network via modem and public phone system on a pay-per-time basis. Usually dial-up connections offer limited bandwidths. The alternative to a dial-up connection is a leased line that offers continuous access at a constant bandwidth to a network.
An electronic technology that generates, stores, and processes data in terms of two states: positive and non-positive. Positive is expressed or represented by the number 1 and non-positive by the number 0. Data transmitted or stored with digital technology is expressed as a string of 0's and 1's. Each of these state digits is referred to as a bit (and a string of bits that a computer can address individually as a group is a byte). Before Digital technology evolved there was analog.
Sound, pictures, text and video available in digital format for downloading or streaming across the Internet or other network.
Digital video is the key to content when streaming media. Digital video is an alternative way of storing or distributing video. Digital video is usually converted from an analog video source. A digital video signal is represented in '1's and '0's, whereas an analog video signal is represented by a fluctuating voltage signal that is stored on magnetic tape. This difference is similar to the difference between analog audio and digital audio.
See Capture.
Process of capturing or "bringing in" audio and/or video (usually analog source tapes such as Beta SP, 3/4, VHS, etc.) into a computer. Digitizing is made possible by video hardware, a computer hardware card, cables, and a software application that all work together to convert the original signal into digital media. This digital media can then be edited and transferred back to numerous formats for Internet streaming, CD-Rom, DVD, and other forms of distribution.
D
Data
Information in the form of words, numbers, or images that has been transcribed into bits. The information can then be read by a computer and stored as memory or sent over the Internet.
Data Rate
The rate at which bits of information are transmitted per second.
Data Type
(Media Type) File format that travels across the RealSystem architecture to RealPlayers.
Database
A collection of data.
Deploy
To use for an intended purpose or end. For example, when the Real Broadcast Network (RBN) is stated as having the largest deployment of RealSystem G2, this means RBN utilizes more of this technology on its network than anyone else.
Dial-Up Access
When computer devices hook up to a network via modem and public phone system on a pay-per-time basis. Usually dial-up connections offer limited bandwidths. The alternative to a dial-up connection is a leased line that offers continuous access at a constant bandwidth to a network.
Digital
An electronic technology that generates, stores, and processes data in terms of two states: positive and non-positive. Positive is expressed or represented by the number 1 and non-positive by the number 0. Data transmitted or stored with digital technology is expressed as a string of 0's and 1's. Each of these state digits is referred to as a bit (and a string of bits that a computer can address individually as a group is a byte). Before Digital technology evolved there was analog.
Digital Media
Sound, pictures, text and video available in digital format for downloading or streaming across the Internet or other network.
Digital Video
Digital video is the key to content when streaming media. Digital video is an alternative way of storing or distributing video. Digital video is usually converted from an analog video source. A digital video signal is represented in '1's and '0's, whereas an analog video signal is represented by a fluctuating voltage signal that is stored on magnetic tape. This difference is similar to the difference between analog audio and digital audio.
Digitize
See Capture.
Digitizing
Process of capturing or "bringing in" audio and/or video (usually analog source tapes such as Beta SP, 3/4, VHS, etc.) into a computer. Digitizing is made possible by video hardware, a computer hardware card, cables, and a software application that all work together to convert the original signal into digital media. This digital media can then be edited and transferred back to numerous formats for Internet streaming, CD-Rom, DVD, and other forms of distribution.
Download
The software that is literally loaded or installed onto your computer from the Web, as opposed to installation via CD-ROM or other physical storage device. VERB: To receive software over the Internet.
DRM
Digital Rights Management. A set of technology and rules that allow content owners to set rights on who, how, when, and with what frequency end users can view content.
DSL
(Digital Subscriber Lines). The two main types of digital subscriber lines are ADSL (Asynchronous) and SDSL (Synchronous). DSL utilizes unused portions of a phone line's bandwidth for transmitting data at high speed, using sophisticated modulation schemes to pack data onto copper wires. They are also known as 'last mile' technologies because they are used to connect only between telephone switching stations to a home or office, not between switching stations.
DSP
Digital Signal Processor - a chip optimized to perform repetitive mathematical calculations, such as encoding and decoding. A DSP normally consumes less battery power due to its specialized nature.
DVCam
DVCAM is developed and supported by Sony. DVCAM uses the same DV25 codec as MiniDV, so it has identical picture quality, yet it has a faster tape speed and a wider track pitch. This means that the data is recorded over a larger area, which reduces dropouts (dropouts are defects in the picture caused by the physical loss of the particles used on the tape to record). This makes DVCAM a much sturdier and dependable format that has found favor with higher-end productions. Also, a MiniDV deck, if used in an analog suite, cannot perform frame-accurate edits, while DVCAM can. This makes it a good choice for post-production houses that want to simply add DV to their existing set- up, but is of no importance to those editing over Firewire. DVCAM can only be recorded in specific DVCAM decks (made by Sony), yet it can be played back in most MiniDV and DVCPRO decks.
DVCPRO
DVCPRO is Panasonic's entry into the DV format arena. DVCPRO has an even wider track pitch than DVCAM (18 microns) and uses a metal-particle tape (as opposed to MiniDV's and DVCAM's metal-evaporated tape) for even better durability. DVCPRO was aimed mainly at the TVs news market, were it has gained some acceptance. Among digital editors it is less used, and its adoption was hampered by an initial short-sighted decision to not include Firewire on DVCPRO equipment, although nowadays DVCPRO equipment has Firewire.
DVD
DVD stands for Digital Versatile/Video Disc, DVDR stands for DVD Recordable and DVDRW for DVD ReWriteable. If you're familiar with regular audio/music CDs or regular DVD-Video discs, then you will know what a recordable DVDR/W looks like. A recordable DVDR/W stores up to 2 hours of very good quality DVD-Video, including several audio tracks in formats like stereo, Dolby Digital or DTS and also advanced menu systems, subtitles and still pictures that can be played by many standalone DVD Players and most computer DVD-ROMs. If you choose to lower the video quality it is possible to store several hours video on a recordable DVDR/W using low bitrates and low resolution with video quality more like VHS, SVHS, SVCD, CVD or VCD. It is also possible to have up to 4.38GB ordinary data or mix DVD-Video and data on a recordable DVD that can be played by most computer DVD-ROMs.
There are three competing DVD Recording standards, DVD-R/W and DVD+R/W have pretty similiar features and are compatible with many standalone DVD Players and most DVD-ROMs while DVD-RAM has less DVD Player and DVD-ROM compatibility but better recording features.
E
E1/T1
A T1 service is a framed communication protocol that delivers a two-way connection at 1.544 Mbit/s each way. In Europe and other countries outside the U.S., the equivalent of T1 is a service called E1 - a two way connection at 2.048 Mbit/s. T1 and E1 define the physical, electrical and framing requirements of the interface. Therefore the actual transmission media is irrelevant and can be different types of lines such as fiber optic or copper wire.
Embedded Player
A RealPlayer placed within a browser window so that only the media clip shows.
Encoder
A hardware or software application used to compress audio and video signals for the purposes of streaming.
Encoding
The act of rewriting or transferring media sources from one format to another (i.e., from VHS tape to RealVideo).
Enterprise
A corporate organization. As a customer group, Enterprise refers to customers who own and deploy across an intranet.
Episode
One media file of a podcast comprises an episode. The file can either be overwritten each time the podcast is upated or the new episode can be added to the podcast, creating an archive of previous episodes.
Extension
An add-on or tool designed to enhance or extend the capabilities and functions of a particular application or product. For example, the Advertising Extension for RealSystem Server adds the ability to incorporate different types of ads into your content.
F
Firewire
A new standard that allows external devices, such as digital video cameras, to transfer data to a computer at very high bit rates (up to 400 Mbps).
Flash
Refers to Web animation software created by Macromedia Inc., which has become an industry standard for Web page development. Flash is vector-based.
Format
Different programs and devices store information in a variety of ways. The specific arrangement of information a program or device requires is called its format. Some types of formatting are VHS, DVD, RealAudio, and so on.
FPS
Frames per second
Frame Rate
The number of frames of video displayed during a given time -- usually measured in seconds. Standard television video is almost 30 Frames Per Second (fps).
Frames Per Second
(FPS) The number of video frames displayed each second. The higher the number, the smoother and sharper the images appear.
G
GIF
(Graphics Interchange Format) A graphics format in which images are constructed of tiny dots, also called pixels, each one colored to correspond to the specific area of the image they represent. This format can be compressed to require fewer memory resources, which is useful in adding images to Web pages.
GPRS
GPRS stands for General Packet Radio Service, and is a step in the evolution of a GSM network towards 3G. GPRS increases data throughput from 9.6kbit/s to 115kbit/s and allows the capability to charge per data bit sent.
Graphics
The pictures, borders, illustrations: everything on a Web page that is not text-based, i.e., graphics. Anything that is produced using a graphics program, even a text title, is considered a graphical element, because it is formatted differently than the plain text that follows it.
GSM
Global System for Mobile Communications - GSM is a digital wireless technology standardized to create a compatible wireless network across Europe. GSM is still most commonly used in Europe, but it is also deployed in other areas of the world. GSM operates in 3 frequency ranges - GSM 900, GSM 1800, and GSM 1900 (also called PCS 1900).
H
H.323
The H.323 standard provides a foundation for audio, video, and data communications across IP-based (but NOT limited to IP!) networks, including the Internet. H.323 is an umbrella recommendation from the International Telecommunications Union (ITU-T) that sets standards for multimedia communications over Local Area Networks (LANs) that do not provide a guaranteed Quality of Service (QoS). These networks dominate today’s corporate desktops and include packet-switched TCP/IP and IPX over Ethernet, Fast Ethernet and Token Ring network technologies. Therefore, the H.323 standards are important building blocks for a broad new range of collaborative, LAN-based applications for multimedia communications.
Highband
Infrequently-used synonym for broadband.
Host
The computer on the other end of a network connection from your computer that contains the information you are trying to access. VERB: network.
Hosting
Storing media files on servers
Hot Colors
Bright or "hot" colors such as bright blues, yellows, and whites do not appear as well as darker colors or earth tones.
HTML
(Hypertext Markup Language) The simple, tag-based language used to create World Wide Web pages.
HTTP
Hypertext Transfer Protocol. The protocol used to distribute web pages. Some streaming media productions are also sent to end-users via HTTP.
I
ID3
An ID3 tag is a data container within an audio file. This data commonly contains metadata for artist name, song title, year and genre of the current audio file. ID3 tags are supported in a few audio formats, the most popular being MP3. The data contained within an ID3 tag is supported by most software and portable media players.
Image
The visual representation of illustrations, photos, almost anything graphic in nature.
Interframe Method
Interframe method is a type of video compression used by MPEG which compresses three types of frames: I-Frames, P-Frames and B-Frames. In I-Frames, the entire scene is compressed. P-Frames are compressed with reference to a Past-I or P-Frame. B-Frames provide the highest amount of compression but require both a past and a future frame as a reference. The image sequence in MPEG is flexible, depending on application specific parameters.
Interstitial
Any web-based advertisement which occurs before, after, or during a narrative content presentation. For example, if streaming media terminology were applied to regular television, standard television commercials would be called interstitials, since they interrupt programming.
Intranet
The internal communications network used by corporations and businesses for data sharing, presentations or other business applications.
IP
(Internet Protocol) The protocol that defines how packets are formatted and addressed when sending data over the Internet. The IP frame header contains routing information and control information associated with datagram delivery. IP is part of the TCP/IP group of protocols.
ISDN
(Integrated Services Digital Network) A set of standards for transmitting digital information over ordinary telephone copper phone lines and other media. With an ISDN adapter (both at your computer and at your Internet service provider), you can send and receive transmissions much faster than using a conventional modem.
ISMA
The Internet Streaming Media Alliance, Inc. is a non-profit corporation formed to create specifications that define an interoperable implementation for streaming rich media -- video, audio and data -- over Internet Protocol (IP) networks.
ISP
(Internet Service Provider) A company that provides personal or business access to the Internet. Many ISPs have a RealSystem Server available to stream media clips.
iTunes
A cross-platform media player application with podcast subscription and Apple media storefront functionality.
iTunes U
iTunes University is an Apple, Inc. hosted service for colleges and universities that provides an iTunes Store-based front end for educational podcasts, downloads, and related audio or video materials.
J
JPEG
(Joint Photographic Experts Group) A compression technique for photos that reduces them to a small percentage of the original file size.
K
KBPS
(Kilobits per second) - The rate at which data is sent over a communication line. The typical household modem runs at 56.6 kpbs.
L
Language
Like human languages, programming languages involve sets of rules and syntax that computers understand, allowing computers to carry out the tasks set by the program. Language can refer to many different types and levels of programming languages, each with particular capabilities and shortfalls.
Local Playback
A file that resides on the same device as the player.
Lossy Compression
Data compression by eliminating perceptually insignificant information. However, since lossy compression introduces inaccuracies, it should only be used with graphics, audio, and video. Data files and executable programs can only be compressed with a lossless algorithm (i.e., a zip file).
Lowband
Infrequently-used synonym for narrowband.
M
M3U
A metafile which points to an MP3 stream.
M4A
An audio-only file using MPEG-4 or AAC compression. M4A files are typically enhanced audio files that contain slides, chapter marks, and hyperlinks. Only a few media players can play AAC files; such as QuickTime, iTunes, RealPlayer, and WinAmp.
M4B
An audio-only file using MPEG-4 or AAC compression. M4B files are typically enhanced audio files that contain slides, chapter marks, and hyperlinks. These files are frequently used for audiobooks and allow bookmarking so that the listener can return to the last listening spot upon resuming play. Only a few media players can play AAC files; such as QuickTime and iTunes.
MBPS
(Millions of bits per second) It is a measure of bandwidth. A unit of information transfer rate. While an Ethernet connection can run at 10 Mbps the average household modem still runs at 56.6 kbps (kilobits per second)
MCU
(Multi-point Control Unit)
Mastering
The process of writing select files in a specific directory structure to a write once, read many media format. Not to be confused with Authoring. See Authoring.
Media
This is the blanket term used when referring to audio, video or images such as photos, as well as the ways they are used to reach the viewer (i.e., streaming media).
Memory
The actual amount of data a computer can store either on a disk or on a chip. Disk memory is a more archival form of storage because it can be saved even when the computer is off. Chip memory is more immediately accessible, but requires electric current to actively remember information.
Metadata
Additional, related information that can be stored as part of the compressed file or kept in a separate database. Examples include CD cover art, movie one-sheet images, or text-based information, such as author, title, etc.
Metafile
A file that minimally contains a URL that points a media player toward a streaming media source. Generally served using HTTP. May be a static file or generated dynamically. Commonly use the filename suffixes RAM (RealNetworks), ASX, WMX (Windows Media), and MOV (QuickTime.
MiniDV
Also referred to as "Regular DV" "Consumer DV" or just "DV," MiniDV is the most common DV tape format. MiniDV provides the most universal playback compatibility. MiniDV tapes can be played in any DV device (including DVCAM and DVCPRO), while many MiniDV devices can play all three formats. MiniDV, as it's name implies, uses only the small DV tapes. Note that while the small DV tapes made by Sony are often marked DVCAM and the tapes made by Panasonic are often marked DVCPRO, it is the device that determines which format is recorded; the tapes are identical. So if a Sony tape that is marked DVCAM is used in a MiniDV camera, the DV data will be recorded as MiniDV.
MOV
File extension for Quicktime movies.
MP3
(MPEG, audio layer 3) A format used for the compression and reproduction of CD-quality audio, which can be downloaded and listened to on a computer or handheld device.
MP4
File extension for MPEG-4. See MPEG-4.
MPEG
(Moving Picture Experts Group) video formatting standard file. A set of digital video compression standards and file formats developed by the Moving Picture Experts Group. There are three major MPEG standards: MPEG-1, MPEG-2, and MPEG-4. MPEG uses a lossy compression method with Interframe compression. Interframe compression assumes that although action is happening, the background in most video frames remains the same.
MPEG-4
MPEG-4 defines how multimedia streams – video, audio, text, data – are transmitted as individual objects. MPEG-4 is a compression/decompression technology that aims to achieve interactivity, efficiency and stability in narrow-band transmissions. On a broader level, MPEG-4 aims to pave the way toward a uniform, high quality encoding and decoding standard that would replace the many proprietary streaming technologies in use on the Internet today. MPEG-4 is also designed for low bit-rate communications devices, such as mobile receivers or wristwatches that can display video. These devices are usually wireless and can have different access speeds depending on the type of connection and traffic. To overcome this problem, MPEG-4 supports scalable content. Content is encoded once and automatically played back and transmitted at different rates, depending on the available network connection.
Multicast
A process which allows a server to send one stream to multiple recipients. This is different from traditional streaming media, where each user connects separately to a server.
Multimedia
The integrated presentation of text, graphics, audio, video and animation, mostly on computers.
N
Narrowband
Used to describe a connection over a computer network which supports a relatively low bit rate. Also sometimes used to describe content optimized for such connections.
Narrowcast
To send data to a specific list of recipients. On the Internet, narrowcasting has also come to refer to programming developed for "niche" interest groups.
Net Congestion
Traffic on the network that slows/delays the transmission of data.
Network
A group of computers linked together, usually by phone lines that can share information and resources. When you are connected to the Internet, your computer is part of a network.
New Media
Term used to describe relatively new forms of media distribution such as the Internet, CD-ROM, DVD, etc.
Noise Reduction
A variety of processes applied to audio or video signals to lower the amount of noise in the given signal.
Nonlinear Editing
Describes the process of editing audio or video where the entire video is available at any given moment for mixing and matching. Nonlinear video editing is to traditional video editing as word processing is to pen and paper.
NT
Short for Windows NT, an operating system from Microsoft usually found on servers.
NTSC
(National Television Standards Committee) - A set of standard protocols developed in 1953 for the broadcast/ reception of television signals within the United States, North America and Japan. It has remained the same since its inception except for the addition of new parameters for the color signal. NTSC scans 525 lines in each image.
O
On-demand
Archived or stored content that viewers can access whenever they want, as opposed to live or one-time-only broadcast events. Programming is available when you want it, instead of when a broadcaster wants to send it.
P
Packet
A small part of a message (i.e., email or streaming media clip) containing data and a destination address that is sent over a network. Parceling messages into smaller pieces and sending them one packet at a time puts a far lighter load on network resources than sending an entire file all at once. Packets usually contain header information with origin and source address, and employs error-correction.
Packet Loss
Data is transmitted in small units known as packets. Occasionally, packets are lost or delayed due to network congestion, resulting in dropped frames. Packet loss causes breaks or hiccups in data, resulting in audio gaps or video distortion.
PAL
(Phase Alternation Line) - The standard protocol for television broadcast/reception used in Europe, Brazil, Argentina, Paraguay and Uruguay. Has 625 lines total, 576 lines visible. Specifically, PAL scans the video image 625 times horizontally.
(Portable Document Format) Developed by Adobe Systems, PDF documents are usually used to present longer or technical information because they open in a window outside of the page they are linked from. This saves space on Web pages while keeping the information handy.
Pixel
One unit of screen information. A video image is composed of individual colored dots, referred to as pixels. Depending on how a monitor is set, a pixel can take up 8 bits/1 byte (256 colors), 16 bits/2 bytes (high color), or 24 bits/3 bytes (true color).
Platform
Often used to define the operating system your computer runs on (i.e., Windows, Macintosh, Linux), but platform can also refer to your computer hardware (i.e., Macintosh or PC).
Player Window
The window in player where you can watch streaming media content.
Plug-in
A type of software that adds a specific capability to a program already on your computer. For instance, your browser probably requires a plug-in to see certain types of animation.
Podcast/Podcasting
Podcasting is a download-only method of distributing media, primarily audio, that allows your audience to retain reproducable copies. Podcasts allow users to follow a special URL that an RSS reader (aggregator) uses to easily download new files as they become available and their accompanying metadata. Further information is available on our Podcasting page.
Pointer Files
Text files that point to the actual location (server and filename) of a streaming file. Almost all systems use pointer files.
PowerPoint
Microsoft Office software that lets you create slide- and narration-enhanced business presentations.
Presentation
Refers to a slide- and/or narration-based business meeting aid.
Progressive Download
A method of delivering audio/video data over the Internet that involves playing the downloaded portion of a file while the download is still in progress. Also referred to as "Pseudo-Streaming".
Protocol
An agreed upon format for transmitting data between two devices, enabling computers to speak to one another. The protocol determines 1) the type of error checking to be used 2) the data compression method 3) the method for discussion between the sending and receiving device. From a user's point of view, the only interesting aspect about protocols is that your computer or device must support the right ones if you want to communicate with other computers. (Source: webopedia.com)
Proxy
A server that sits between a client (in our case the RealPlayer) and a server. The proxy intercepts requests to see if it can fulfill the requests itself. If not, it forwards the request to the real server. In the digital media world, proxies are used to improve end-user experience and reduce bandwidth.
Pseudo-Streaming
See Progressive Download.
Q
QuickTime
Multimedia architecture used by software tool vendors and content creators to store, edit and play synchronized graphics, sound, video, and music.
QT
Quicktime media file extension.
R
RAM
A metafile, which points to a Real Media file.
Real Time
The actual time an event takes place. For example, real time can refer to a live broadcast or an active exchange between a host and user.
RealAudio
The file format developed by Real Networks that is used to stream audio over the Internet.
RealFlash
Describes a Flash presentation synchronized with a RealAudio soundtrack, playable in Real Networks client software.
RealMedia
Brand name describing file formats, server software, player software, and protocols used by streaming media systems from Real Networks, a leading streaming media platform vendor.
RealPix
A Real System format (file extension= .rp) for streaming still images over a network.
RealPlayer
Real Networks software that lets you play multimedia presentations streamed by Real System Server or a Web server.
RealSystem Server
Real Networks server software used to stream multimedia clips to RealPlayer.
RealText
A Real System format (file extension= .rt) for streaming text over a network. It uses a mark-up language for formatting text.
RealVideo
The file format developed by Real Networks that is used to stream video over the Internet.
Resolution
Described in dots per inch (dpi), resolution refers to the clarity and detail of an image. On a 15-inch monitor there are usually 680 pixels of width, times 480 lines of height. This multiplies to a total of around 300,000 pixels, or a resolution of around 50 dpi. The higher the dpi, the more clear and precise the image will appear.
Resources
The term used to describe anything you draw upon and need for a particular task. For example, emailing a large file requires network resources, which include the size of the server, the speed of connection, scalability and so on.
Rich Media
Media that has been enhanced with animation or video. Rich media ads are animated, and often streamed, so that they appear more like television commercials, as opposed to ads containing static images and text. They can be embedded in Web pages and inserted into or between video clips. Using SMIL, they can be streamed concurrent to audio programming.
RM
Real Media extension.
RMVB
Real Media extension, where media is utilizing variable bit rate.
Router
A network component that serves as both a Bridge and a Router.
RSS
(Really Simple Syndication) – An XML format document that allows aggregator software to subscribe to a feed of frequently updated files.
RTP
(Real Time Protocol) – An Internet protocol that defines the transmission of real-time data, such as audio and video. RTP provides mechanisms for the sending (server) and receiving (client) applications to support streaming data.
RTSP
Real-Time Streaming Protocol: a standard method of transferring audio and video and other time-based media over Internet-technology based networks. A descendent of UDP.
S
SDK
(Software Development Kit) A SDK is a group of products and/or software that helps a programmer develop applications for a specific platform.
Secam
Input signal format used in Europe, Brazil, Argentina, Paraguay and Uruguay, and a few other countries. Has 625 lines total, 576 lines visible.
Server
A software application, such as a Web server or RealSystem Server, that sends clips over a network.
A computer that runs server software.
Shockwave
Macromedia’s animation plug-in program that displays animation on Web browsers. Shockwave movies are built using Director, a multimedia authoring tool.
Signal
When you send an email, for example, it is delivered via a signal a bundle of information containing your message that travels over the phone lines. A television signal on the other hand, is data that is transmitted over the airwaves which tells your television what colors to show and which sounds to produce.
Simulated Live
Describes a completed audio/video program which is presented on the web as though it were live. Audience members must tune in to the program. If the scheduled start time has already passed, audience members will join the program in progress.
SMIL
(Synchronized Multimedia Integration Language) A text-based markup (layout) language based on XML that allows content owners to divide the RealPlayer area into static images, text, video and slides similar to how one would lay out a web page. SMIL synchronizes disparate media elements within one streaming media presentation.
SQL
Structured Query Language. Used to manipulate data from a relational database.
Storage Device
Here, storage device refers to many kinds of hardware used to save data. These all come with an amount of memory, which is available on either a portable disk, a hard-drive disk or digital tape.
Stream
To send a media clip over a network so that it begins playing back as quickly as possible.
Streaming Media
Streaming media technology enables the real time or on demand distribution of audio, video and multimedia on the internet. Streaming media is the simultaneous transfer of digital media (video, voice and data) so that it is received as a continuous real-time stream. Streamed data is transmitted by a server application and received and displayed in real-time by client applications, e.g. RealPlayer or Windows Media Player. These applications can start displaying video or playing back audio as soon as enough data has been received and stored in the receiving station’s buffer. A streamed file is simultaneously downloaded and viewed, but leaves behind no physical file on the viewer's machine.
SureStream
A technology that allows switching between higher and lower bandwidth streams in a single RealAudio or RealVideo file to compensate for network congestion. Available only in RealSystem G2 and above.
S-Video / Y/C
The Y stands for luminance, the monochrome parts of your TV picture. The C stands for the chrominance, the color parts of your picture. Put them both together and you have a full color picture. In composite video, the color and luminance signals have been combined into one signal traveling over one wire. With Y/C, the color signals travel over a separate wire from the luminance signals, using two wires instead of one.
S-VHS
Super-VHS is a format that has higher resolution and overall better picture quality than regular VHS. SVHS has an overall better quality, less "video" noise. Less color smearing etc.
T
T1
A very common digital leased-line connection capable of carrying data at 1.544 Mbps.
T3
Similar to a T1, but can carry data at 44.736 Mbps, equivalent in bandwidth to 28 T1 lines.
Tag
A programming language tool that contains formatting directions.
TCP
(Transmission Control Protocol) – Standard protocol designed for transmitting text and ASCII data across the Internet and other IP-based networks. Provides automatic detection and retransmission of lost packets, resulting in accurate end-to-end transmission but also often resulting in considerable transmission delay.
Transcoding
The conversion of one digital file format to another digital file format (i.e., MP3 to Windows Media). The ideal method for encoding to multiple streaming media formats is to use the original, uncompressed source material and encode it into the new formats, avoiding transcoding completely.
Transmit/ transmission
Used in the context of both television-style broadcasting, as well as in reference to digital communication over phone or cable lines between computers.
U
UDP
User Datagram Protocol. A method of communicating between computers which does not guarantee that ever bit arrives at its end destination. Favored for time-sensitive data such as streaming media.
Unicast
A process which forces each individual user to make an individual connection to a server to receive a stream.
UNIX
A generic term applied to several similar operating systems usually found on servers.
URL
(Universal Resource Locator). A descriptor that lets a web browser or media player receive a clip stored on a Web server or streaming server.
V
VBR
Variable Bit Rate (VBR) is an encoding method that ensures consistent high audio quality throughout an encoded file by making intelligent bit-allocation decisions during the encoding process. VBR encoding produces an overall higher and more consistent quality level than Constant Bit Rate encoding.
Vector Graphics
Refers to graphics based on mathematical algorithms. As opposed to GIF or PNG pixel-based graphics, vector graphics can be resized infinitely without losing clarity.
VHS
Refers to a consumer grade, video tape format.
VHS-C
This is a compact version of VHS, with the same characteristics as standard VHS only in a smaller cartridge. This format requires an adapter cartridge to play in a standard VCR.
Video Compression
The process through which a complete video file is reduced in size. Video Compression algorithms take advantage of the fact that there is minimal difference from "one" frame to the next. The first frame is encoded and then the sequence of differences between frames. This is also known as "inter-frame" coding or "3D coding"
Video DVD
See DVD.
Video Hotlinks
Hyperlinks that are embedded in video images much like image maps. Users can click on certain parts of a video image and be taken to a URL, a new movie, a different part of the same video, or many other actions.
Video On Demand
Describes video content which may be viewed by the end-user from beginning to end, at any time. Video that can be accessed at any time by the user.
Video Service Provider
(VSP) - Video Service Providers are analogous to Internet Service Providers (ISPs) except that they specialize in providing multimedia storage and streaming services for Internet sites. In this scenario, when a company offers streaming applications on their Internet site, clicking on the video or multimedia file will transparently connect users to the Video Service Provider that stores and streams the content.
VOD
(Video on Demand) See Video on Demand.
Voice Over IP
(VoIP) - The practice of using an Internet connection to pass voice data using IP instead of using the standard public switched telephone network. This allows a remote worker, for instance, to function as if directly connected to a PBX even while at home or in a remote office. In bypassing the public network, it also avoids standard long distance charges, as the only connection is through an ISP. VoIP is being used more and more to keep corporate telephone costs down.
W
W3C
World Wide Web Consortium, an Internet standards body.
Walled Garden
This term refers to a browsing environment that is controlled by one specific entity. On the Internet, a walled garden refers to portals that give users limited access to a number of internal sites without the user having to leave their session with that portal. Written By: Robert Orange
WAP
(Wireless Application Protocol) A protocol that defines delivery and access of information to WAP-enabled wireless devices.
WAV
(Wave Form Audio) - Files with the .wav extension are digital representations of sound and typically take up a good deal of space to store (typically 50MB for a 5 minute song, for instance). If you use software to rip files from an audio CD, it is usually stored in .wav format. Standard Windows sounds are also stored in .wav format.
Webcast
The act of webcasting. Also refers to an individual program which has been, will be, or is being webcast.
Webcasting
(also known as Internet Broadcasting) Capturing, encoding, and hosting a live event, such as a concert, award show, meeting, or conference, usually from a remote location, for Internet broadcast on a one-time or limited basis. Live events usually require establishing an internet connection and/or satellite uplinks for streaming over the Internet. Live events can also be archived for viewing on demand.
Webisode
A single webcast episode.
Windows Media
The streaming media platform released by Microsoft.
Windows Media Audio
Describes an audio file format associated with the Windows Media platform.
WMA
See Windows Media Audio.
WMV
See Windows Media Video.
X
XML
Extensible Markup Language is an open-standard, general-purpose, markup language used to disseminate metadata, typically in tandem with media files, such as podcasts.
Y
Z
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