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Constant Bit Rate (CBR) — Constant bit rate encoding means that the rate at which
codec output data is consumed is constant. CBR is useful for streaming multimedia content
on data communication channels which operate more efficiently or require the bit rate to
remain within a tight tolerance. Typically the constant bit rate is created by stuffing bits into a
variable bit rate signal which has a defined peak or maximum limit.
Constrained Variable Bit Rate (CVBR) — This scheme is similar to
Variable Bit Rate
(VBR), (see page 115) but sets a maximum allowed bit rate that the encoder cannot
exceed.
Darwin Streaming Server (DSS) — Darwin Streaming Server is software developed by
Apple that provides a high performance media streaming server for delivering content.
The software is used to simultaneously stream to a broad range of screens and devices
(including computers, televisions, smartphones, and tablets).
Data bits — The number of bits used to represent one character of data. Data bits can be
7, 8, or 16, but most serial devices use 8 bits for ASCII characters.
DDC — Display Data Channel (DDC) is a bidirectional communications standard
developed by VESA (Video Electronics Standards Association) that defines a universal data
transmission standard for the connectivity between display devices and computers.
Decoder — 1) In analog video, a device used to separate the RGBS (red, green, blue and
sync) signals from a composite video signal. Also known as an NTSC decoder. 2) In digital
systems, a device which does the reverse of an encoder, undoing the encoding so that
the original information can be retrieved. The same method used to encode is usually just
reversed in order to decode. Video over IP decoders accept IP data streams and output
an analog or digital video signal. 3) In control systems, the device in a synchronizer or
programmer which reads the encoded signal and turns it into a form of control.
Dynamic Host Configuration Protocol (DHCP) — A network protocol that enables
a server to automatically assign unique network addresses (IP address, subnet mask,
gateway) to a device using a defined range of numbers configured for the network.
DiffServ (Differentiated Services) — DiffServ specifies a scalable, coarse-grained
mechanism for classifying and managing network traffic and providing quality of service
(QoS).
Domain Name System (DNS) — A database system that translates domain names
(such as www.extron.com) into IP addresses.
Dynamic IP address — An IP address that is automatically assigned to a client device in
a TCP/IP network, typically by a DHCP server. Network devices that serve multiple users,
such as servers and printers, are usually assigned a static (unchanging) IP address.
Extended Display Identification Data (EDID) — A data structure used to communicate
video display information, including native resolution and vertical interval refresh rate
requirements, to a source device over the Display Device Channel (DDC). The source device
outputs the optimal video format for the display based on the provided EDID, ensuring
proper video image quality.
EDID Minder — Automatically manages EDID communication between connected devices.
Elementary Stream — Raw
H.264 (MPEG-4 AVC) Glossary
(see page 111) video or
AAC
raw
audio (see page 109), not wrapped by additional headers.
Encoder — A hardware device or software program used to compress (encode) or change
a signal from one format to another or convert an analog signal into a digital data stream.
The SME 211 is an encoder that converts analog audio and video into digital streams.
SME 211 • Reference Information
110
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