Extron electronic SMD 101 manual Glossary

Glossary

Advanced Audio Coding (AAC) — A standardized compression and encoding scheme for lossy (low quality) digital audio. Higher bit rates provide higher quality. Part of the MPEG-2 and MPEG-4 specifications. The SMD 101 supports AAC-LC (MPEG-2 part 7, MPEG-4 part 3, sub-part 4 and part 14, MP4 audio).

Advanced Video Coding (AVC) — Video compression format, H.264/MPEG-4 part 10. See the H.264 (MPEG-4 AVC) definition.

Address Resolution Protocol (ARP) — A protocol for assigning an IP address to a device based on the device MAC (Media Access Control) address or physical machine address, that maintains a table showing the correlation between the two.

B-frames— Bi-predictive frames (B-frames) reference video frames before and after the current frame. They offer significantly better compression than I or P frames, but are not available in Baseline profile.

Bandwidth — A measure of available (or used) data communication resources. The total range of frequencies or bit rate required to pass a specific signal without significant distortion or loss of data. The maximum bit rate at a specified error rate, expressed in bits per second (bps). The device bandwidth should be wider than the highest possible bandwidth of the signals it could be required to process.

Bit rate — The number of bits that are conveyed or processed per unit of time. Bit rate is quantified using the bits per second (bit / s) unit, often in conjunction with an SI prefix such as kilo- (kbit / s or kbps), mega- (Mbit / s or Mbps), or giga- (Gbit / s or Gbps).

Codec — A hardware device or software program used to encode or decode a digital data stream or signal. Loosely, a combination of coder-decoder or compressor-decompressor.

Compression — Reducing the amount of data required to represent a picture (or a stream of pictures) and sound before sending or storing it.

Constant Bit Rate (CBR) — This scheme adjusts the output bit rate so that it stays very close to the specified target bit rate.

Constrained Variable Bit Rate (CVBR) — This scheme is similar to Variable Bit Rate (VBR), but sets a maximum allowed bit rate that the encoder cannot exceed.

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 bi-directional 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 — A hardware device or software program used to decompress (decode) or change a signal from one format to another or convert a digital signal into analog. The SMD 101 is a decoder that converts compatible digital AV streams into a video and audio HDMI signal or to HDMI AV plus analog audio.

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.

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 user, such as servers and printers, are usually assigned a static (unchanging) IP address.

SMD 101 • Reference Information 94