B

Bandwidth
The data transfer capacity of a digital communications system, such as the Internet or a LAN. Bandwidth is usually expressed in the number of bits that a system is capable of transferring in a second: bits per second (bps). High bandwidth or broadband refers to a network capable of a fast data transfer rate.

Bit rate
The speed at which digital audio and video content is streamed from a source, such as a file, to be rendered properly by a player, or the speed at which binary content in general is streamed on a network. Bit rate is usually measured in kilobits per second (Kbps), for example, 28.8 Kbps. The bit rate of a Mpeg-4 file or live stream is determined during the encoding process, when the streaming content is created. Bandwidth is the total bit rate capacity of a network. For audio and video content to render properly when streaming over a network, the bandwidth of the network must be high enough to accommodate the bit rates of all the different content that is concurrently being streamed.

C

CD quality
Audio that is encoded by using uncompressed PCM at 44.1 kHz and 16 bit stereo. A CD and an audio stream encoded at CD quality sound identical.

Codec
Abbreviation for compressor/decompressor. An algorithm or scheme used when recording digital video or audio. A codec is used, for example, when video is transmitted over the Internet; the video is compressed on the sending end and decompressed on the receiving end. Users can select a codec based on the audio or image quality, and image size preferred.

Compression
The coding of data to reduce file size or the bit rate of a stream. Content that has been compressed must be decompressed for playback. A codec contains the algorithms for compressing and decompressing audio and video.

Content
Data that an encoder or server streams to a client or clients. Content can originate from live audio or live video presentation, stored audio or video files, still images, or slide shows. The content must be translated from its original state into Mpeg-4 format before VideoNet can stream it.

D

Deinterlace
To combine two interlaced fields into a single frame and render them at 30 frames per second (fps). Deinterlacing is done to remove artifacts and improve the quality of encoded video.

Delta frame
Frames that contain only the changes from the previous frame.

Encode
To convert information into a specified digital format for convenient storage and retrieval by using computer technology, usually involving compression technology and encryption technology.

I

Intelligent streaming
A type of streaming that detects network conditions and adjusts the properties of a video or audio stream to maximize quality. Intelligent streaming is only available for content encoded using a multiple bit rate profile.

Interlace
To display video by using a half-resolution image known as a field. Interlaced video uses two video fields to make a single frame of video. Each field of video contains alternating lines of an image: field one displays the odd numbered lines and field two displays the even numbered lines. Interlacing saves bandwidth when the video is transmitted over the airways or on cable.

Inverse telecine
The process that intelligently removes the frames that were added when 24 fps film was converted to 30 fps video. ISO MPEG-4 video codec version 1.0
A type of codec based on the ISO MPEG-4 standard. It enables you to encode content produced by many consumer electronics devices, such as digital video cameras and cell phones.

L

Looping
The process in which file-based content is played repeatedly until encoding is completed. Looping ensures that you have no interruption in the stream as a result of reaching the end of a file before completing a broadcast or capture session.

Lossless compression
Data compression techniques in which no data is lost.

Lossy compression
Refers to data compression techniques in which some amount of data is lost. Lossy compression technologies attempt to eliminate redundant or unnecessary information.

M

Multicast
A one-to-many connection in which multiple clients can receive the same stream from a server. To receive a multicast, a client must have access to a multicast-enabled network. In contrast, a unicast is a one-to-one connection in which one client receives a distinct stream from a server.

Multicast station
A defined location from which a player can receive streams. In effect, it is an IP address and a port.

N

National Television Standards Committee
The standards body that is responsible for setting television and video standards in the United States. The NTSC standard for television defines a composite video signal with a refresh rate of 60 half-frames (interlaced) per second. Each frame contains 525 lines and can contain 16 million different colours.

NTSC
See National Television Standards Committee

NTFS
An advanced file system designed for use specifically within the Windows 2000 operating system. It supports file system recovery, extremely large storage media, and long file names. It also supports object-oriented applications by treating all files as objects with user-defined and system-defined attributes.

P

PAL
See Phase Alternating Line Phase Alternating Line The dominant television standard in Europe. Whereas The NTSC, the U.S. standard, delivers 525 lines of resolution at 60 half-frames per second, PAL delivers 625 lines at 50 half-frames per second. See also NTSC.

Pixel format
The colour depth of an image, usually measured in RGB or YUV.

Profile
A predefined group of settings that match content type and bit rate with appropriate audio and video codecs.

Pulse code modulation
A sampling technique for digitizing analogue signals, especially audio signals. When you encode audio by using PCM, no compression is applied.

R

RGB
A colour model that describes colour information in terms of the red (R), green (G), and blue (B) intensities that make up the colour.

S

Source
The type of content that VideoNet can encode: audio, or video. Audio and video content is captured from a card installed on your computer or from a file that was converted to Mpeg-4 format.

Source group
Audio and video that are encoded into a stream and played by the Client by the use of a Mpeg-4 compliant Player.

Stream
Data transmitted across a network and any properties associated with the data. Streaming data enables the player to begin rendering the data immediately instead of waiting for the entire file to be downloaded.

T

Target bandwidths
The number of bits that are transferred to users based on the speed of their network connections.

Telecine
The film-to-video conversion system that adds frames to video to compensate for the differences in frame rates between film and video. When converting 24 fps film to 30 fps NTSC video, an additional 6 frames per second are added.

Time-to-live
In multicasting, a value that defines the number of routers through which a multicast can pass before a router stops forwarding the multicast.

TTL
See time-to-live

U

UDP
See User Datagram Protocol

Unicast
A one-to-one client/server connection during which the client receives a distinct stream from the server. No other client has access to the stream. Each client has its own connection to the server and a separate content stream must be generated for each client requesting content from the server.

User Datagram Protocol
A communication protocol that sends a data unit or datagram from one computer to another. It does not sequence the packets that the data arrives in, but it does provide a checksum capability to verify that the data arrived intact.

Y

YUV
A colour model that describes colour information in terms of luminance (Y) and chrominance (U, V).