V/IT Glossary—27 Days of #AVabc—Q



QuickSwitch HD® Technology—Handling high-definition digital media means handling HDCP (High-bandwidth Digital Content Protection), the encryption scheme that content providers use to protect their DVDs, Blu-ray discs, and broadcast signals against unauthorized copying. Viewing HDCP encrypted content requires a source device to "authenticate" each display and signal processor in the system and issue each one a "key" before the content can be viewed. 


Ordinarily this causes a complete loss of signal for up to 15 seconds each time a new source or display is selected anywhere in the system. To make matters worse, every source device has a limited number of keys available, so connect too many displays and the source will simply stop outputting a signal without warning.


Not to worry—Crestron QuickSwitch HD® manages the keys for every HDCP-compliant device in the system, maintaining continuous authentication for each device to ensure fast, reliable routing switching.



Q-factor (Quality factor)A measure of the “quality” of a resonant system. Resonant systems respond to frequencies close to the natural frequency much more strongly than they respond to other frequencies. On a graph of response versus frequency, the bandwidth is defined as the 3 dB change in level besides the center frequency.

QoS—Quality of service. Performance, such as transmission rates and error rates, of a communications channel or system. A suite of features that configure queuing and scheduling on the forwarding path of an E-Series router. QoS provides a level of predictability and control beyond the best-effort delivery that the router provides by default. (Best-effort service provides packet transmission with no assurance of reliability, delay, jitter, or throughput.). Also see "CoS."

QS-FPC™—QuickSwitch Front Panel Controller. This is a front panel controller on Extron matrix switchers. The panel allows easy set up and control of the matrix switchers through a series of buttons on the front panel.

Quad Split—A process resulting in four full video images on one screen, each occupying one quarter of the screen. Quad splitting allows the use of one monitor for four video sources simultaneously, useful for video editing, duplication and studio control, as well as for security applications

Quad Standard—A term used for video products that are compatible with the following four standards: NTSC 3.58, NTSC 4.43, SECAM, and PAL.

Quantization—The process of sampling an analog signal to convert its values into digital data.

Quantizing Error—Inaccuracies in the digital representation of an analog signal. These errors occur as a result of limitations in the resolution of the digitizing process.

Quantizing Noise—The noise (deviation of a signal from its original or correct value) that results from the quantization process. In serial digital video, it is a granular type of noise that occurs only in the presence of a signal.

Quantization Word Length—The number of bits created by the A/D converter at each sample point. Compact Disc records quantization words 16 bits in length.

QUXGA—Quad UXGA, a computer resolution of 3200 x 2400 pixels (four times 1600 x 1200)


Leave a comment

Please note, comments must be approved before they are published