Glossary - Extron electronics SMP 300 Series User Manual

Glossary

Ad hoc recording — An ad hoc recording session is one that has been set up for a
specific occasion or task without being previously scheduled.
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 SMP 300 Series 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 on page 165).
Address Resolution Protocol (ARP) — A protocol for assigning an IP address
MAC (Media Access Control)
(see page 166) to a device based on the device (see
page 166) address or physical machine address, that maintains a table showing the
correlation between the two.
Archive stream or streams — The primary encoding streams are used to create
recordings, and they can also be used for streaming. Archive streams are typically higher
resolution than confidence streams.
Aspect ratio control — The aspect ratio of the video output can be controlled by selecting
a fill mode, which provides a full screen output, or a follow mode, which preserves the
original aspect ratio of the input signal.
Auto-Image — An Extron technology for scan converters and signal processors that
simplifies setup by executing image sizing, centering, and filtering adjustments with a single
button push.
Auto Memory — Auto memory recalls input and image settings for signals that have
previously been applied. If this feature is disabled, the device treats every newly applied
input as a new source.
B-frames — Bi‑directionally predictive coded picture. Contains predictive, difference
GOP
information from the preceding and following I‑ or P‑frame within a (see page 165).
Data preceding or following the B‑frame are required to recreate video information in a
B‑frame. They offer significantly better compression than I or P frames, but are not available
in Baseline profile.
Bandwidth — The total range of frequencies required to pass a specific signal without
significant distortion or loss of data. In analog terms, the lower and upper frequency limits
are defined as the half power, or ‑3 dB signal strength drop, compared to the signal strength
of the middle frequency, or the maximum signal strength of any frequency, expressed as
xx Hz to xx kHz (or MHz) @ ‑3 dB. In digital terms, it is 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 may handle. (In general, the wider the
bandwidth, the better the performance. However, bandwidth that is too wide can pass
excessive noise with the signal.)
Baud — The speed of data transmission, often in bits per second or megabits per second.
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).
SMP 300 Series • Glossary 162