This glossary provides a brief description of Vbrick products and defines streaming video terminology used or referenced in our documentation. This includes common terms and acronyms used in the streaming media industry. For more information about any of the Vbrick products listed below, go to our website or contact Vbrick Support Services. If you notice missing or incorrect terminology or want more information, send e-mail to documentation@Vbrick.com

Works by detecting a user's bandwidth and CPU capacity in real time and adjusting the quality of a video stream accordingly. It requires the use of an encoder which can encode a single source video at multiple bit rates. The player client switches between different encoded bit rates resulting and a good experience for both high-end and low-end connections.

The DME supports Advanced Audio Coding (AAC) audio a standardized, lossy compression and encoding scheme for digital audio. Specifically, the DME supports MPEG-4 AAC with ADTS headers. The DME does not support AAC w/ ADIF or LATM/LOAS headers.  The DME does not support any version of HE-AAC audio.

An electrical signal that has a continuous nature rather than pulsed or discrete. An example is the traditional format in which multiplexed video and audio are transmitted using an RF carrier, modulated by changes in amplitude and phase induced by video and audio signals. See digital.

Asymmetrical Digital Subscriber Line. A traditional two-wire telephone line which for both high-speed digital computers and conventional analog telephone service. Called asymmetrical because the data transmission rate is higher in one direction than the other.

Unwanted visual distortions that appear in a video image, such as cross-color artifacts, jitter, blocking, ghosts, etc. Artifacting is a common side effect of compression, especially at lower bit rates.

Advanced Systems Format. An extensible file format designed to facilitate streaming digital media data over a network. See Windows Media formats.

Describes the ratio of width to height of an image. Standard Definition television has an aspect ratio of 4:3; High Definition is 16:9.

Refers to two or more electrical signals having the same average nominal rates but de-synchronized with respect to one another. The term asynchronous is also often used in telecommunications to refer to serial 1 bit wide transmissions used between computer systems. See synchronous.

The electrical signal loss in a transmission system such as a local telephone loop or private line connection.

A communication layer within the ATM protocol. The ATM layer is the adaptation layer or AAL. AAL layers start a 0 and transgress to 5. AAL0 actually means no AAL layer and AAL 5 is the highest layer which can accommodate very large packet sizes.

Audio Video Interleaved. A digital media file format for storing sound and video.

Short for bi-directional frame. A video compression method used by the MPEG standard. In a motion sequence, individual frames of pictures are grouped together (see GOP) and played back so that the viewer registers the video’s spatial motion.

(1) A range of frequencies between two defined limits expressed in cycles per second, or hertz (Hz). It is also the information carrying capacity of a circuit. (2) The expression of the carrying capacity of the transmission line. In a digital transmission, the bandwidth is the range of transmission rates at which information can be sent in a particular medium. The bandwidth is expressed in kilobits per seconds or megabits per second (Mbps). (3) The capacity of a transmission channel.

A unit of transmission speed equal to the number of times the state (or condition) of a line changes per second. The baud rate usually refers to the number of bits transmitted per second (BPS).

Some Vbrick VB6000 Series models have built-in mini-browsers that support viewing of limited HTML pages. The billboard feature lets you display text and/or graphics on a monitor. The HTML pages are saved in the Vbrick or can be located on a remote HTTP server.

The number of bits transferred per unit of time, typically expressed in bits per second. For example, a file compressed to 28.8Kbps contains 28.8 kilobits of data for each second. Similarly, a 28.8Kbps modem can transfer a maximum of 28.8 kilobits of data per second.

In color video, the characteristics that makes pictures appear to be most intense, created by luminosity; also the quality of being filled with light.

A transmission medium designed for high-speed data transfers over long distances. Cable modem services and DSL are examples of broadband networks.

An area of computer memory reserved for temporarily holding data before that data is used on the receiving computer. Buffering protects against the interruption of data flow.

An area where frequently used information is kept readily available. A cache improves performance by reducing delay caused from unnecessary and redundant data transfer. A computer browser speeds page retrieval by storing local copies of recently viewed pages.

Text that accompanies images or videos, either as a supplemental description or a transcript of spoken words. See closed captioning.

Constant bit rate. A characteristic of a data stream in which the bit rate remains nearly uniform for the duration of the stream. CBR traffic requires guaranteed levels of service and throughput.

Compact disk. An optical storage medium for digital data. CD-R is compact disk-recordable—a type of CD on which files can be copied, but not erased or replaced. CD-RW is compact disk-rewritable—a type of CD on which files can be copied, erased, and replaced.

Common Interface Format or Common Image Format. The Common Interface Format was developed to support video conferencing. It has an active resolution of 352 x 288 and a refresh rate of 29.97 frames per second. See also SIF, resolution.

In audio, an audible distortion that occurs because an input or output level exceeds the equipment's dynamic range. The term clipping is analogous to the "cutting-off" of the highest excursions of the audio signals.

Text information added to the video signal. It can be descriptive text (sub-titles or information for the hearing impaired) and/or the words being spoken in the program. The data for the captions are included in the video signal but outside the active video image. They are placed on line 21 of the vertical blanking internal. It is called closed because it is not seen unless it is called up by the receiving device.

Encoder/decoder. A process or device by which or in which a signal is encoded for transmission or storage then decoded for playback. As a process it is the algorithm that handles the compression and decompression of video or audio files. As a device it a Vbrick appliance that accomplishes the encode/decode process.

A picture signal combined with synchronization and (possibly) color information. Usually called baseband video, or just video.

Reduces the amount of bandwidth need to transmit a digital file or a live stream. lossless compression describes a technique that compresses the original signal in exact form; lossy compression discards unnecessary content prior to compression. Lossy compression is commonly used for video.

The maximum rate, in bits per second, at which data can be transferred between a network and a computer or device.

Constant bit rate. A characteristic of a data stream in which the bit rate remains nearly uniform for the duration of the stream. CBR traffic requires guaranteed levels of service and throughput. See MBR and VBR.

Vbrick’s VEMS and VEMS Mystro are Video Content Management Systems. A CMS is responsible for the creation of a site's framework including image media, audio files, web content, skins, etc. CMS is a cost effective way to deliver and manage content.

Refers to the control used to set the peak white level of the picture or the ability of the set to show a large difference between black level and white level. A high contrast picture will appear to have more detail.

Three colors—red, blue, and green—are used in television to produce all colors. These separate scanning beams (one for each color) must strike their targeted phosphors (screen's internal coating) with precise accuracy. If the beams are out of alignment, the image and colors are muddied.

Dynamic Adaptive Streaming over HTTP is a developing standard for adaptive streaming over HTTP that has the potential to replace existing proprietary technologies like Microsoft Smooth Streaming, Adobe Dynamic Streaming, and Apple HLS.

Reducing the size of a data file by reducing unnecessary information, such as blanks and redundant data.

In TCP/IP, the basic unit of information passed across the Internet is called an IP datagram. It consists of a complete unit of information containing source and destination IP addresses along with protocol-specific information and user data.

Data Communications Equipment. A device that establishes, maintains and terminates a session on a network. It may also convert signals for transmission. It is typically the modem.

To decode compressed audio and video content to a specified digital format. A decoder converts live or prerecorded audio and video content that was compressed during encoding. Vbrick supports MPEG-1, MPEG-2, and MPEG-4, decoders.

Dynamic Host Configuration Protocol. Allows administrators to centrally manage and automate the assignment of IP addresses in a network. DHCP lets a network administrator supervise and distribute IP addresses from a central point and automatically sends a new IP address when a computer is plugged into a different place in the network.

The transmission of discontinuous electrical signals containing information encoded in binary form that has only two possible states: 0 or 1. Digital signals have the distinct advantage over analog because they are easily transported and replicated without loss to the original. See also analog.

Domain Name System. The name resolution system that lets users locate computers on a Unix network or the Internet (TCP/IP network) by domain name. The DNS server maintains a database of domain names (host names) and their corresponding IP addresses.

Digital rights management. A technology that provides a persistent level of protection to digital content by encrypting it with a cryptographic key. Authorized recipients (or end users) must acquire a license in order to unlock and consume the content.

Data Terminal Equipment. That part of a data station that serves as a data source, data sink, or both. It is the part of the terminal that interfaces with the communications circuit.

To convert audio and video content to a specified digital format. An encoder converts live or prerecorded audio and video content to a specified digital format. Typically, content is compressed during encoding. Vbrick supports MPEG-1, MPEG-2, MPEG-4, and WM encoders.

Recovers data lost from transmission dropouts or packet loss. Error correction requires additional overhead in the transmitted data stream. In Windows Media Player, error correction ensures that digital data is read accurately during playback or copying.

A baseband LAN specification invented by Xerox Corporation and developed jointly by Xerox, Intel, and Digital Equipment Corporation. Ethernet networks operate at 10Mbps using CSMA/CD to run over coaxial cable. Ethernet is similar to a series of standards produced by IEEE referred to as IEEE 802.3.

Failover is a backup operational mode in which the functions of a system component (such as a processor, server, network, or database, for example) are assumed by secondary system components when the primary component becomes unavailable through either failure or scheduled down time. Used to make systems more fault-tolerant, failover is typically an integral part of mission-critical systems that must be constantly available. See redundancy.

A combination of hardware and software that enforces a boundary between two or more networks and prevents unauthorized access to a private network.

Repeated rapid increase and decrease of pitch of the reproduced audio, more than about two repetitions per second, due to non-uniform linear speed of analog tape. Also choppy rapid breakup and resynchronizing of a television picture from any cause.

One of many sequential images that make up video. Frame rate is the number of video frames displayed per second. Higher frame rates generally produce smoother movement in the picture. See I-frame, P-frame, key frame.

Number of video frames per second. NTSC television is 30 frames per second. On the Internet, frame rate is dependent upon the bandwidth available and the multimedia format from which the video file is produced.

File Transfer Protocol. An Internet protocol that allows a user on one host to transfer files to and from another host over a network.

The ability to transmit and receive data simultaneously. For ethernet LAN connections, this implies the presence of media and ethernet controller hardware that is capable of transmitting and receiving at the same time on both ends of the connection. See half-duplex.

A router (or any computer) that performs protocol conversion between different types of networks or applications. For example, a gateway can convert a TCP/IP packet to a NetWare IPX packet and vice versa. Gateways perform complete conversions from one protocol to another rather than simply supporting one protocol from within another, such as IP tunneling.

Group of Pictures. The collection of I, B, and P frames comprises a Group of Pictures. The selection of GOP parameters is a trade-off between bandwidth, quality, sensitivity to transmission error, and delay. An extended GOP will be more sensitive to transmission errors.

A video compression standard jointly developed by the ITU. Also known as AVC (Advanced Video Coding) or MPEG4 Part 10.

The ability to transmit or receive data in one direction at a time. See full duplex.

High Definition Compatible Digital. A patented encode/decode process that improves the quality of all forms of digital audio recording and playback by increasing resolution and reducing distortion that occurs during analog-to-digital (A/D) and digital-to-analog (D/A) conversion, digital processing, and digital filtering.

Generally any video image with more than 480 horizontal lines (North America) or 570 lines (Europe) is considered high-definition. 720 scan lines is generally the minimum even though many systems greatly exceed that. See also Standard Definition (SD).

A standard for consumer electronic devices that improves the compatibility between computers and CD or DVD players.

A request for a single file from a web server. Hits are also referred to as a web request. See also page views which results from a user clicking a link on an HTML page which points to a different page.

HTTP Live Streaming (or HLS) is an adaptive streaming communications protocol created by Apple for iOS devices and Macs running OSX in Snow Leopard or later. With HLS you create multiple files for distribution to the player, which can adaptively change streams to optimize the playback experience. As an HTTP-based technology, no streaming server is required, so all the switching logic resides on the player.

Hyper Text Markup Language. The language used in the World Wide Web to create web pages with links to other documents, rich text enhancements (bold, italic, etc.) and so on. The "source" file for what you see on a web page is written in HTML.

HTML 5 allows the Web browser to become a development platform ensuring interoperability among browsers so that Web applications and documents behave the same way no matter which browser is used to access them. It is a comprehensive application development platform for Web pages that eliminates the need to install third-party plugins.

Hypertext Transfer Protocol. The Internet protocol used to deliver information over the World Wide Web.

The default protocol for streaming audio and video over the Internet. It involves the simultaneous download and viewing/listening of the file through HTTP.

A forwarding technique that allows a stream to effectively bypass a firewall protecting a LAN. A streaming server is configured to send data to the intended destination client over HTTP (port 80); the client sends responses back to the server in the same manner.

A "single color" disregarding brightness or luminance. The simplest way to describe hue is to say that pink and red are of the same hue and azure, blue, and navy are of the same hue. Hue control is the same as tint control.

A video frame that is encoded without reference to other frames (see P-frame and B-frame) and which encode differences between the current frame and a previous frame or future frame. An I frame must be decoded before video can be displayed.

Internet Control Message Protocol uses datagrams to report errors in transmission between the host and gateway.

A high-speed serial bus standard that provides enhanced computer connectivity for a wide range of devices, including consumer electronics audio/video (A/V) appliances, storage peripherals, other computers, and portable devices.

The Internet Control Message Protocol defined by the IETF (Internet Engineering Task Force) document RFC 792. ICMP messages are layered over IP and are used to implement "ping" (or ICMP echo) and to report various IP communication errors.

The process of adding content to a VOD server. This process adds the content to the VOD server's database and includes analysis of the content to allow fast forward and rewind. See also trick control.

To display a video frame in two fields. One field contains the even lines of the frame, the other field contains the odd lines. During playback, the lines in one field are displayed first, then the lines in the second field are displayed.

A mobile operating system developed and distributed by Apple. Originally released in 2007 for the iPhone and iPod Touch, it has been extended to support other Apple devices such as the iPad and Apple TV. Apple does not license iOS for installation on non-Apple hardware.

Also called an Internet address. This is a 32 bit address assigned to hosts on an IP network. The address is written in dotted decimal format as four eight-bit numbers (or octets) separated with periods.

Integrated Services Digital Network. The recommendation published by CCITT for private or public digital telephone networks where binary data, such as graphics and digitized voice and data transmission, pass over the same digital network that carries most telephone transmissions today.

To display a video frame in two fields. One field contains the even lines of the frame, the other field contains the odd lines. During playback, the lines in one field are displayed first, then the lines in the second field are displayed.

Also called an Internet address. It is a 32-bit address assigned to hosts using TCP/IP. The address is written as four octets separated with periods (dotted decimal format) that are made up of a network section, an optional subnet section, and a host section.

Internet Streaming Media Alliance. A group of industry leaders (including Vbrick) whose goal is to accelerate the adoption and deployment of open standards for streaming rich media content such as video, audio, and associated data over Internet protocols.

All devices in the network derive their timing signal directly or indirectly from the same primary reference clock.

Integrated Web Server. Vbrick's appliance configuration application that uses a web interface. Used to configure and manage MPEG-2, MPEG-4, and WM devices over an IP connection.

Communication timing distortion caused by an inconstant latency in digital or analog signal propagation. Jitter can cause data loss, particularly at high data rates.

Joint Photographic Experts Group (JPEG) Industry organization developing standards and specifications for the encoding of photographic images over various media and network technologies.

A video frame containing all the data needed to construct an image without reference to previous frames. See I-frame.

(Key-Length-Value) is a data encoding standard, often used to embed GPS information in video feeds. Items are encoded into Key-Length-Value triplets, where key identifies the data, length specifies the data's length, and value is the data itself. Defined in SMPTE 336M-2007.

The delay that occurs while data is processed or delivered. The delay between the time a device receives a frame and the frame is forwarded out of the destination port.

Lightweight Directory Access Protocol. A protocol used to access a directory listing. LDAP support is being implemented in Web browsers and e-mail programs which can query an LDAP-compliant directory. Supported in VEMS for authentication and authorization.

A Windows Media file that has an associated license that defines how the file can be played. The restrictions stated in the license vary depending on the license creator. When a CD track is copied by using Windows Media Player, a license can be assigned to the newly created file. Under that license, the file can only be played on the computer where the file was created.

Video circumstances where picture and sound are not synchronized in time. Lip movement that does not match the words spoken. Video processing units like line doublers that accumulate several frames of video can introduce lip sync error.

Relieving a resource constraint by distributing processing or traffic across multiple devices. For instance, serving video content from multiple VOD servers or sending network traffic across multiple network paths.

A process for compressing data in which information is arranged in a more concise form and restored to its original state upon decompression.

A process for compressing data in which information is removed and cannot be recovered upon decompression. Typically used with audio and visual data in which a slight degradation of quality is acceptable.

Brightness of a light emitting object, or the portion of a video signal that represents brightness. Used by itself, the luminance signal is sufficient to produce a full black and white image.

A Media Access Control (MAC) address is a hard-coded interface identification used by layer 2 devices (switch or bridge) for proper forwarding of frames between computers on a network. MAC addresses are usually represented as a group of 6 hexadecimal numbers as in the following example: 00:50:c2:00:c5:35.

Multiple bit rate. A characteristic of a data stream in which the same content is encoded at several different bit rates in order to optimize content delivery. See CBR and VBR

Digitized data of any type that can be used to improve a web video. Allows measurability, and indexing. Most sharing sites allow forms of metadata such as file descriptions and keywords for searching.

Management Information Base. A database of information on managed objects that can be accessed via network management protocols such as SNMP and CMIP. MIB object can be accessed and managed using the VBSDK.

Multiple bit rate. A characteristic of a data stream in which the same content is encoded at several different bit rates in order to optimize content delivery. See CBR or

Data about data. Information about digital media content such as the artist, title, album, producer, and so on. Vbrick encoders allow insertion of real-time metadata strings into the video stream and decoders can receive and act on the real-time metadata to trigger operations such as URL flips.

Musical Instrument Digital Interface. A specification of the MIDI Manufacturers Association (MMA). The specification defines a protocol for describing music data, such as note on and note off messages; a file format for storing music data, called Standard MIDI; and a standard hardware interface.

Moving Picture Experts Group. The committee that creates international standards for coding audio-visual information to a digital, compressed format. The acronym MPEG is appended to the beginning of individual specifications developed by the committee. For example, MPEG-2 refers to the standard, ISO/IEC - 11172.

MPEG Audio Layer-3. An audio compression standard.

Microsoft Media Server protocol. A proprietary protocol using UDP or TCP to deliver content as a unicast stream.

Communication between a single sender and multiple receivers on a network. Useful for content delivery where a single stream is transmitted to multiple clients not connected to the server. The server sends one copy of the stream to multicast-enabled routers which replicate the data. Clients receive the stream by monitoring a specific multicast IP address and port. See unicast.

An IP address that uniquely identifies a multicast stream of packets on a network. Same as group address. A multicast sender sends packets to such an address and a multicast receiver receives packets from such an address. Multicast addresses (also called Class D addresses) are in the range 224.0.0.0 to 239.255.255.255.

An audio reproduction system that processes several, typically more than two, channels of sound. For example, 5.1 multichannel audio refers to a surround sound system in which there are five primary channels and a subwoofer channel.

National Television System Committee. In the United States, a television industry group that develops standards for television broadcasting and receiving equipment. Used in the U.S., Canada, and Japan. See PAL.

Predictive (or predicted) frame. A video compression method used by the MPEG standard. In a motion sequence, individual frames of pictures are grouped together (see GOP) and played back so that the viewer registers the spatial motion. A P-frame follows an I-frame and contains only the data that has changed from the preceding I-frame (e.g. color or content).

Continuous sequence of binary digits of information is switched through the network and an integral unit. Consists of up to 1024 bits (128 octets) of customer data plus additional transmission and error control information.

A network in which data is transmitted in units called packets. The packets can be routed individually over the best available network connection and reassembled to form a complete message at the destination.

A request to load a single page of an Internet site. A page request results from a user clicking a link on an HTML page which points to a different page. See also hits which refer to a request for a file from a web server. There may therefore be many hits per page view. Page Views are also called Page Impressions.

Phase Alternating Line. 625 line TV encoding standard used in England, Western Europe except France) and Australia. See also SECAM and NTSC.

Serial port passthrough lets users control remote devices like cameras, DVDs, or VCRs that are connected to the serial port on an appliance. Vbricks have up to two serial ports that can be used for passthrough and each operates at its configured baud rate (e.g. 115.2–300K bps). Some common applications include remote control of a camera (pan-tilt-zoom), remote control of security doors, low speed data transport, or data collaboration between PCs.

Protocol Data Unit. The technical name of a frame of data transmitted over the data link layer in a communications network such as Ethernet or Token Ring. Many people simply call every unit of data travelling over a network a "packet."

Packet Internet Groper. Software test where a PC bounces special IMCP packets off a destination host to check for presence and availability.

Picture in Picture. A small video image is superimposed on a specified area of the monitor to allow the user to see two independent videos on a single monitor. Vbrick encoder/decoder models use PIP (configurable in IWS) to show an image of the encoder's video along with the decoder's video. PIP is often used in two-way video applications to allow the local user to monitor the video being sent along with the video being received.

Picture element. The smallest spot on a video display device that can be resolved as having a different brightness or color from what is next to it. The complete video image is a rectangular array of pixels.

A checkerboard-like coarse grainy effect over portions of a picture due to inability of the processing of digital video to keep up with subject motion and other frame to frame changes. Sometime used to mask or censor part of the picture content.

A list of digital media content.

Digital media files distributed over the internet which can be played on portable media devices such as iPods. Podcasting can be used to transmit advertisements directly to consumers.

A mobile electronic device that can exchange files or other data with a computer or device. Examples of portable devices include Pocket PCs, portable digital music players, and Smartphones.

An electronic device that increases the output level of a signal to match the required signal input level of another device.

A dynamically generated list of all video streams currently available on the network, often based on the receipt of a Vbrick SAP. You typically navigate a Vbrick decoder or set top box program guide using an IR remote control to choose a program. You typically navigate the StreamPlayer or MCS Portal Server program guide by clicking on a program entry.

A technique for downloading Internet video and/or audio clips so that they can be viewed at the same time that they are being transferred to your computer. This provides some of the benefits of streaming media without requiring a streaming media server.

A set of formats and procedures that enable computers to exchange information.

A procedure that enables switching from one protocol to another when a player fails to make a connection using a particular protocol.

A server located on a network between client software, such as a web browser, and another server. It intercepts all requests to the server to determine whether it can fulfill them itself. If not, it forwards the request to another server.

Clients access content streams from a Microsoft Windows Media server by connecting to a publishing point. Windows Media Services includes two types of publishing points: on-demand and broadcast. Either type can be configured to deliver a stream from one of several types of sources, such as a live stream from a Vbrick WM Appliance, a file, or a playlist. One Windows Media server can be configured to run multiple publishing points, hosting a combination of broadcast and on-demand content.

To deliver data to a client upon client request. For example, a Windows Media Player or a Windows Media Server can pull streams from a Vbrick WM Appliance. See push.

To deliver data to a server without a server request for the data. For example, a Vbrick WM Appliance can push streams to a Windows Media Server publishing point. See pull.

Quality of Service. Term for the set of parameters and their values which determine the performance of a given virtual circuit.

Redundant Array of Independent Disks. A multi-drive storage solution that provides high performance and redundant hardware for fault-tolerant protection against failure.

An Internet protocol that delivers real-time audio and video streams over multicast or unicast networks.

An internet specification for streaming media. RTSP can control multiple data delivery sessions, provide a means for choosing delivery channels such as UDP, multicast UDP and TCP, and provide a means for choosing delivery mechanisms based upon RTP.

Redundancy is the concept of storing content and having access availability from more than one location. Redundancy is starting point for any business continuity plan designed to address the needs of any mission critical systems. See failover.

The conversion of a set of samples to become a larger or smaller set of samples, for example a 720 by 480 pixel video frame to a 360 by 240 pixel video frame. See sampling.

The clarity or sharpness of the picture. Also the size of a video frame, measured in pixels. Analog resolution standards generally refer to lines of horizontal resolution as shown below. See also CIF, SIF.

Real-Time Transport Protocol. An Internet protocol that delivers real-time audio and video streams over multicast or unicast networks.

Real Time Streaming Protocol. An internet specification for streaming media. RTSP can control multiple data delivery sessions, provide a means for choosing delivery channels such as UDP, multicast UDP and TCP and provide a means for choosing delivery mechanisms based upon RTP.

A dedicated computer hardware and/or software package which manages the connection between two or more networks.

Super video. A video signal transmitted as two subsignals requiring two separate wires: luminance (Y) and color (C). S-video can represent standard definition interlaced video signals only. The S-video cable plug has separate pins for color and luminance.

Synchronized Accessible Media Interchange. An XML-based language for specifying closed captions in multiple languages and styles.

The process of converting an analog entity to digital form. In the case of a picture, a large number of evenly spaced spots (samples) are taken and each represented as one or more numbers for brightness (luminance) and color. These spots are referred to as picture elements or pixels. The more samples are taken, the more accurate (with higher resolution) an image can be reconstructed from the samples. See RAID.

The sampling rate is the number of samples per second used to store a sound; measured in hertz (Hz) or kilohertz (kHz).

Session Announcement Protocol. Vbrick uses SAPs to announce the presence of a device on the network. If configured, each Vbrick periodically multicasts a SAP announcement to the network which can be detected by listeners. For example, StreamPlayer listens for program SAPs and can launch a stream; VBDirectory listens for management SAPs and can be used to configure or update a device.

The strength or amount of a certain color present in a television picture; saturation is expressed as the purity of the color.

Small Computer System Interface. SCSI is a hardware interface that allows for the connection of up to 15 peripheral devices to a single PCI board called a "SCSI host adapter" that plugs into the motherboard.

Session description protocol. Multicast configuration file for MPEG-4 audio, video, and network settings.

Sequential Couleur Avec Memoire. A 625 line 50 interlaced field per second analog broadcast standard used in Europe, primarily in France.

Search Engine Optimization. Process by which search engines are optimized to search more effectively for specific content. SEO typically allows users to search for particular videos more efficiently than typical search engines.

See passthrough.

A low-cost solution that replaces a destination decoder and typically streams to a television. See VEMS Digital IP Receiver.

Standard (or Source) Input Format. This video format was developed to allow the storage and transmission of digital video. The 625/50 SIF format has a resolution of 352 x 288 active pixels and a refresh rate of 25 frames per second. The 525/60 SIF format has a resolution of 352 x 240 active pixels and a refresh rate of 30 frames per second. The computer industry, which uses square pixels, has defined SIF to be 320 x 240 active pixels, with a refresh rate of whatever the computer is capable of supporting. See also CIF, resolution.

A Microsoft application framework for writing and running rich Internet applications (including video), with features and purposes similar to those of Adobe Flash.

A user interface that provides an alternative appearance and customized functionality for software such as Windows Media Player.

Simple Network Management Protocol. The Internet network management protocol. SNMP provides a means to monitor and set network configuration and runtime parameters. SNMP can be used to control Vbrick appliances.

Features 480 interlaced lines of vertical picture resolution and a 4:3 aspect ratio. Standard Definition televisions have a lower pixel count than High Definition televisions and are more prone to ghosting, static noises, and poor reception. See also High Definition (HD).

A method of delivering digital media across a network in a continuous flow over networks and the Internet. The digital media is played by client software as it is received. Streaming files match the encoded bit rate to the connection speed of the user so the remote viewer can play audio or video with minimal stoppage without first downloading the entire video file.

Used to group IP addresses together. Routers use a subnet mask to define the group (or IP subnet) to which an IP address belongs so that it can identify the correct interface from which it should forward an IP packet.

Super VGA. A computer video signal format with 800 pixels horizontally and 600 pixels vertically. This format was originally defined based on a video memory size of half a megabyte for 256 colors, or one 8 bit byte per pixel.

Secure Shell. Proprietary software that provides secure logon for Windows and Unix clients and servers. SSH replaces telnet, ftp and other remote logon utilities with an encrypted alternative.

In Windows Media Player, the process of maintaining digital media files on a portable device based on the rules in a partnership or actions specified by the user. This may require copying digital media files from a computer to a device, updating information on the device, or deleting files from the device.

Operating at the same speed. All circuits in a synchronous network are constrained to operate at their nominal rates with no significant variation. See asynchronous.

Digital transmission facility operating with a nominal bandwidth of 1.544Mbps. Also known as Digital Signal Level 1 (D1). Composed of 24 DS-0 channels in many cases. The T1 digital transmission system is the primary digital communication system in North America.

Digital transmission facility operating at 45Mbps bandwidth. Composed of 28 DS-1 channels in many cases. Also known as DS-3.

Transmission Control Protocol/Internet Protocol. The common name for the suite of protocols developed by the U.S. Department of Defense in the 1970s to support the construction of world-wide inter-networks. TCP and IP are the two best-known protocols in the suite. TCP corresponds to Layer four (the transport layer) of the OSI reference model—it provides reliable transmission of data. IP corresponds to layer three (the network layer) of the OSI reference model—it provides connectionless datagram service.

Television from Cinema. Machine used to transcribe movie film content onto electronic media. The most common mechanism in professional equipment does not use a video camera but instead has a "one pixel" sensor that scans across an illuminated film frame however many lines (480 for NTSC) are needed. Such a mechanism is called a flying spot scanner.

A small representation of a page or image. Thumbnails provide a convenient way to browse through multiple images before retrieving the one you need. Programs often let you click on the thumbnail to retrieve it.

A ticker or crawler is a small screen space dedicated to presenting headlines, promotions and other vital pieces of information typically at top or bottom of screen.

On a DVD, typically, the largest unit of content, such as a movie or TV program, is called a title. There is not a consistent standard across all DVDs and because of this, a DVD can contain one or more titles.

An individual song or other discrete piece of audio content.

Transmission Control Protocol. The protocol within TCP/IP that governs the breakup of data messages into packets to be sent via IP, and the reassembly and verification of the complete messages from packets received by IP.

A (Windows) Internet utility that describes the path in realtime from the client machine to the remote host being contacted and reports the IP addresses of all the routers in between. IWS provides a traceroute utility to test Vbrick devices.

Generally an individual song or other discrete piece of audio content. Also a distinct element of audio visual information, such as the picture, a sound track for a specific language, etc.

The process whereby a digital bit stream is converted from one compression method to another. For example, an H.264 stream or file is transcoded when converted to a Windows Media stream or file. Transcoding is more CPU-intensive than transmuxing because transcoding often requires a complete decode/encode and in many cases requires a transmux process as well. The VEMS NVR has standard features to automatically transmux H.264 transport stream files to H.264 mp4 files and vice versa. The VEMS Portal Server has a purchasable option that will transcode files when using the Add Video feature.

The process whereby a digital bit stream is converted from one file format or streaming protocol to another—without changing the compression method. An example of transmuxing is when a unicast stream is converted to multicast or when an RTP stream is converted to RTMP. Transcoding is less CPU-intensive than transcoding. The DME, for example, transmuxes streams; it does not transcode streams.

Transrating means changing the bitrate (bandwidth) of a stream by means of processing. For example, processing an input video stream of 1Mbps so that the output stream is 256Kbps only. Transrating can increase or decrease the bitrate.

To test for a particular condition in a running program. An error trap tests for an error condition and provides a recovery routine. A debugging trap waits for the execution of a particular instruction in order to stop the program and analyze the status of the system at that moment.

Fast forward and rewind of VOD content.

User Datagram Protocol. A connectionless transport protocol in the TCP/IP protocol stack that is used in cases where some packet loss is acceptable, for example, with digital media streams. UDP is present on top of IP at the same level as TCP.

A method used by media servers for providing content to connected clients in which each client receives a discrete stream. No other client has access to that stream. See multicast.

Uniform Resource Locator. An identifier which describes the location of a particular piece of information ("document") including the protocol used to retrieve that information. For example, http://www. interop.com/publications/connexions.html says: Use the HTTP protocol to retrieve the file "connexions.html" from host "www.interop.com" in directory "publications."

Variable bit rate. A characteristic of a data stream in which the bit rate fluctuates depending upon the complexity of the data. Suitable for applications that produce traffic of varying bit rates, like common LAN applications, which produce varying throughput rates. See CBR and MBR.

Video CD. A compact disc format that contains ISO MPEG-1 compressed full-motion video and associated high-quality audio.

The file type of a video. Different video formats are used by different programs and/or operating systems. Some popular formats for digital video are .avi (Microsoft), .mov (Quicktime), .wmv (Windows), and .flv (Flash).

A series of requests to a website from the same uniquely identified visitors with a set timeout. A visit may contain multiple hits and page views.

In Windows Media Player, a graphical display that changes in response to the audio signal.

Video-on-demand. Generic acronym for any streaming video server that can store and serve video streams when requested by end users.

The process of automatically increasing or decreasing the volume during playback to make all audio content sound similar with respect to volume levels. Volume leveling may change the original dynamic range of the content.

Virtual Private Network. A network service offered by public carriers in which the customer is provided a network that in many ways appears as if it is a private network (customer-unique addressing, network management capabilities, dynamic reconfiguration, etc.) but which is actually provided over the carrier's public network facilities.

A digital media file format for storing sound.

A web camera) is a small camera connected to a computer, usually through a USB port. Webcams usually produce small, progressive-scanned images.

A live broadcast over the web. An online distribution of audio and/or video to multiple viewers or listeners at the same time.

A standardized on-screen representation of a control (e.g. scroll bars, buttons, and text boxes) that can be manipulated by a user.

A server that stores and retrieves HTML documents and other Internet or intranet resources using HTTP. Also called an HTTP server.

A file that contains audio, video, or script data. The content of the file is encoded with one of the Windows Media codecs.

The format of a digital media file or stream that was encoded with Windows Media codecs. Some Windows Media formats are listed below.

See Vbrick WM Encoders.

Optical zoom relies on the camera lens to bring the subject closer in a recorded video. Digital zoom does not use the lens but enlarges a portion of the image digitally. Digital zoom is more powerful than most optical zoom features but may cause grainy images.

The DME is a versatile, highly‑configurable media distribution engine that moves streaming media to and from a wide variety sources and endpoints. It can for example take a unicast RTP stream and multicast it to thousands of local IP users, or it can transmux and serve the same RTP stream to RTMP (Flash) users on the Internet.

EtherneTV is a legacy enterprise-wide solution composed of a set of scalable, industrial strength, network-aware appliances that allow organizations to build a video infrastructure on top of any existing IP network. Each component plays a significant role in capturing, recording, managing, distributing, and viewing your video assets. EtherneTV has been superseded by VEMS.

Integrated Web Server. Vbrick's appliance configuration application that uses a web interface. Used to configure and manage MPEG-2, MPEG-4, and WM devices over an IP connection.

The ViP is Vbrick software designed for 3Com Open Services Networking enabled routers and switches, transforming the module into a web-based video portal for accessing live streams and on-demand Windows Media video assets. The ViP enables automated discovery of live video from Vbrick WM appliances and provides browser-based access to stored video assets onboard the OSN's internal storage or via any web server or Windows Media streaming server.

IBM Lotus Sametime is an enterprise instant messaging and web conferencing application. The Vbrick Sametime Video Plug-in enables IBM Lotus Sametime clients to instantly display any Vbrick live or stored video. All video assets are automatically displayed in an expandable tree hierarchy, allowing the user to rapidly select the "channel" they wish to view. The Vbrick Plug-in supports live and stored MPEG-1, MPEG-2, MPEG-4 and WM video.

Vbrick PC application used to view Live and On-Demand streams, including full play, pause, stop, fast forward, rewind, and seek capabilities. StreamPlayer can discover program names on a network by listening for a session announcement (SAP) from Vbrick devices. When you click a program name, StreamPlayer launches the stream in Windows Media Player. StreamPlayer Plus is an enhanced version that adds support for stream recording. StreamPlayer Plus is available for Windows, Linux, and Solaris and also includes a web deployment toolkit that lets you embed video in web pages.

VBAdmin is a management interface that lets you manage Vbrick H.264 appliances from an external browser. You can launch VBAdmin in Internet Explorer or Firefox. You connect to VBAdmin by pointing to the IP address of the appliance and logging in. VBAdmin is one of several ways you can manage the Vbrick encoder. You can also use Telnet, the Command Line Interface, or other methods.

Vbrick Online Streaming Services (VBoss) consists of VBoss Engage and VBoss Broadcast. VBoss Engage is a video service that delivers live video and displays it on a customized viewing portal with private branding. VBoss Broadcast is a live video broadcasting service that provides cut-and-paste code to insert live video into your own web pages; it also delivers template-driven viewing pages.

VBCast consists of VBCast XStream and VBCast Express which are pre-installed in a hard, durable travel case. Designed for use by emergency first-responders and news crews, VBCast broadcasts high-quality video and audio signals connected via wireless, hard-wire, cell-phone, or a satellite uplink on Vbrick appliances. You connect your audio and video sources, your transmission device, and begin broadcasting in minutes.

Vbrick kit for corporate vertical that consists of VBPresenter software, a Vbrick WM Appliance, a Sony video camera, and the accessories, cables, and connectors you need to create multimedia VBPresenter presentations. See also VBEduCast.

Vbrick kit for education vertical that consists of VBPresenter software, a Vbrick WM Appliance, a Sony video camera, and the accessories, cables, and connectors you need to create multimedia VBPresenter presentations. See also VBCorpCast.

Vbrick PC application used to discover Vbrick devices on a network by listening for management session announcements (SAPs). When you click a device name, VBDirectory launches the IWS management application for that device. Also used to initiate an upgrade using VBDownload or VBAdministrator.

VBDNA (Vbrick Dependable Network Appliance) is the family name for the code base used in some Vbrick network video appliances. VBDNA software runs on Vbrick MPEG-2, MPEG-4, and WM (Windows Media) network appliances.

Vbrick PC application used to download updates to Vbrick devices. Can be launched as a standalone application or from VBDirectory.

An external Vbrick hardware device that uses the passthough port on an encoder to send control commands via an infrared link to third-party devices like VCRs, DVDs, etc. The VBIR can be programmed with codes representing IR command sets that are compatible with devices from many manufacturers.

Vbrick PC application used to stream live multimedia presentations (including synchronized PowerPoint slide shows) using a Vbrick WM (Windows Media) Appliance. It also works with Vbrick's ETV Portal Server and Vbrick's VOD servers or with a VBStar to deliver multimedia presentations over the public Internet or a private LAN.

VEMS is the redesigned and feature-rich successor to Vbrick's EtherneTV solution. It is an enterprise-wide solution composed of a set of scalable, industrial strength, network-aware appliances that allow organizations to build a video infrastructure on top of any existing IP network. Each component plays a significant role in capturing, recording, managing, distributing, and viewing your video assets.

The Vbrick WM (Windows Media) Appliance converts analog video and audio from any source into digital Windows Media streams. It attaches to your network and delivers streaming video and audio to any Windows Media-compatible player or server. The Vbrick WM Appliance can deliver the streams via multicast to any number of players on the network and it can serve the stream via unicast to up to 200 players or servers.

The H.264 appliances represent Vbrick's newest networked video appliances. Capable of supporting both standard definition and high definition video delivery, the H.264 appliances allow organizations to deliver video in a wide range of quality—from 3G to HD—over any network infrastructure. The H.264 appliance provides significantly improved quality for a given bit rate, allowing organizations to deliver a better customer experience for any given bandwidth.

VB1000-2000-3000 Series. Vbrick's MPEG-1 network video appliances encode/decode NTSC or PAL video at TV quality and audio at CD quality. Configured with VBAdmin. This product has been superseded by Vbrick's MPEG4 and Windows Media VB4000-5000-6000 appliances.

VB4000-5000-6000 Series. Vbrick's MPEG-2 network video appliances provide DVD quality video and CD quality audio at 1–15 Mbps of bandwidth. MPEG-2 is the world's most popular digital compression technology and is used to encode DVDs as well as Digital Cable and Digital Satellite broadcasts. Configured with IWS.

VB4000-5000-6000 Series. Vbrick's MPEG-4 encoders and decoders are versatile and reliable video appliances for one or two-way interactive communications over low or medium bandwidth IP networks. The Vbrick MPEG-4 encoder/decoder can be used for webcasting, multicasting, transcoding, and two-way interactive video. Configured with IWS. Designed for streaming over the Internet at lower bit rates (56K, 128K, 384K0 and over a LAN at higher rates (1Mbps and above).

A reflector receives a stream from a WM encoder and retransmits the stream to players or other reflectors. In many applications, Vbrick appliances are used both as encoders and as reflectors but since Vbricks are compatible with other devices in the Microsoft Windows Media ecosystem, you can just as easily use a Vbrick as the encoder and a Microsoft or Real Helix Server as the reflector, or you can use a Microsoft encoder or Microsoft Windows Media Server as the source of a stream for a Vbrick reflector.

Vbrick's software development kit lets end users write custom applications to control Vbrick appliances. The SDK includes the VB1000-2000-3000 SDK for MPEG-1 devices; the VB4000-5000-6000 SDK for MPEG-2, MPEG-4, and WM devices, and the ETV-STB-SDK for VEMS Set Top Boxes. The VBSDK is sold separately and is not bundled with other products.

Streaming Distribution System. A customized Vbrick product solution that includes all streaming media components in one movable cabinet. It may include encoders/decoders, VCRs, DVDs, and all associated cabling and control software configured in "slices."

Security, Surveillance, and Monitoring. The VBSSM-MP2 and VBSSM-MP4 are MPEG video‑only encoders for security and surveillance monitoring applications where high-quality, bandwidth-efficient video is required. The VBSSM is a compact, ruggedized device that supports temperature ranges from -20 to 70°C.

These MPEG-2 VB4000-50000-6000 Series encoder/decoders include all of the basic features of the MPEG-2 appliances and add the capability of recording incoming streams for store and forward use on an included 60GB hard drive.

See Vbrick Enterprise Media System.

The VEMS Portal Server is a web-based portal for accessing live streams and on-demand audio and video assets. The Portal Server provides the central capability and management for the Vbrick VEMS architecture. The user interface provides the ability to locate available media assets from Windows PCs, Macs, Linux® PCs and IP Receivers. DVD-like controls make viewing easy.

The VEMS Portal Server enables organizations to record two simultaneous video streams from anywhere in their organization. With the addition of the capabilities of the Network Video Recorder, you can scale up to 40 concurrent recordings. New Network Video Recorders can be added at any time enabling your system to scale with your needs.

The Vbrick VEMS Digital IP Receiver (previously called the EtherneTV Set Top Box) is an MPEG decoder for cost sensitive installations that require large-scale deployment. The IP Receiver is controlled through an IR remote. The Vbrick Digital IP Receiver is integrated with Vbrick VEMS to provide an automated streaming solution for both live streams and stored content. It supports MPEG-1, MPEG-2 and MPEG-4 and can be deployed either as a stand-alone device or with VEMS for enhanced functionality.

The Windows Media IP Receiver is a Windows Media decoder for cost sensitive installations that require large-scale deployment. The IP Receiver is controlled through an IR remote. It can be used to access live streams, request stored content from a VEMS VOD-WM server or access the web. The Vbrick IP Receiver is integrated with Vbrick's VEMS Portal Server and provides an automated streaming solution for both live WM streams and stored WM content.

Vbrick's VOD-W video-on-demand servers use a Windows-based operating systems on Dell hardware. They ingest and stream unicast and multicast streams in the following formats: MPEG-1, MPEG-2, MPEG-4 RTSP unicast; MPEG-1, MPEG-2, MPEG-4 multicast; H.264 RTSP unicast, and H.264 multicast.

Vbrick's VOD-WM (Windows Media) video-on-demand servers use a Windows-based operating systems on Dell hardware. The VOD-WM server provides all standard video-on-demand features including support for Windows Media files.

Darwin Open Source server for Linux, Windows, Mac, etc. Ingests and plays MPEG-4 content only. Requires an FTP server. The Darwin server is the open source version of Apple's QuickTime Streaming Server and has the same code base as QuickTime.