Selecting the Right Scalers
What are Scalers?
AV systems typically incorporate several input sources such as computers, videoconferencing equipment, cameras, and mobile devices, with different video signal formats and resolutions. It is common, though, for a display not to accept the wide range of video resolutions often found in professional AV environments. When integrating these various sources into a system, using a scaler to convert the inputs to a common video format provides maximum flexibility. To achieve the highest image quality, digital displays should be driven at native resolution. Scalers achieve this by their ability to accept a wide range of input signal formats and then generating video output to match displays of various native resolutions.
The process of converting from low resolution to higher resolution is known as video upscaling or upconversion. If the input signal is composite video, then decoding, or the process of separating the composite signal into its component elements, is necessary. Superior scalers feature 3D comb filters for video decoding, to preserve fine picture detail and to minimize dot crawl. When the input signal is standard definition NTSC or PAL, de-interlacing will often be required. A high quality scaler features motion-adaptive de-interlacing to maximize picture detail while avoiding jagged horizontal lines. If the input video was originally a film, then pulldown detection may be deployed to restore video frames that were compromised in the telecine process. High quality scalers have advanced pulldown detection for multiple pulldown cadences, such as 3:2 and 2:2.
Conversely, the process of converting from high resolution to a lower resolution is known as video downscaling or downconversion. If the output signal is to be a television format such as NTSC 480i, the process is called scan conversion. The scan conversion process is complicated by the fact that some information in the original high resolution image may be lost in the conversion to a lower resolution. For example, if the original image has a resolution of 1024x768 pixels and it is being converted to 720x480 pixels for NTSC video, it will be necessary to compress or eliminate 304 pixels on the horizontal plane and 288 pixels on the vertical plane. Deciding which information is redundant, and which is important, requires a significant amount of signal processing. High performance scan converters include specialized, adjustable image filters that can be used to minimize the loss of detail and provide the best possible image when the original resolution is reduced.
Video cross conversion is the process of converting between different signal formats at similar resolutions. For example, a 1080i TV signal may need to be converted to 1080p or to WXGA 1280x800 for display on a projector. To accept 1080i signals, high resolution deinterlacing is needed. As is the case with scan conversion, superior video cross conversion is characterized by minimal loss of fine detail in the video output.
Additional Scaler Functionalities
The displays in an AV system may not always accept the signal formats of the system's source devices, such as HDMI, DisplayPort, or 3G-SDI, or the various resolutions that each video format supports. In matrix switching environments particularly, video formats may need to be converted to or from the switcher's video format in order to connect with different sources and displays. Extron scalers accommodate a broad range of video formats and resolutions, providing the ability to integrate both digital and analog devices into an AV system.
Extron scalers offer exceptional switching capabilities. Often, a display's built-in switching can be slow and have visible transient glitches. Extron scalers streamline system operation and deliver professional quality presentations by providing fast, glitch-free switching. Seamless switching models are available with selectable transition effects. In addition, SpeedSwitch® technology provides exceptional switching speed for HDCP-encrypted content.
Professional environments sometimes require multiple displays to show the same video signal. Many Extron scaler models offer multiple outputs, allowing a video signal to be sent to more than one display simultaneously. Sometimes one display may be required to show multiple sources simultaneously in windows. Extron offers scaler and signal processor products that not only enable several sources to be shown on a single display, but also allow the user to control the size and location of each window and manipulate the layout.
AV systems incorporating scalers only require one video connection to the display input compared to several connections otherwise. The cost savings from running fewer long cables and simpler installation can justify the additional expense of a scaler.
In professional environments, end users demand consistent, reliable performance and excellent image quality. Quite frequently, professional AV systems must accommodate a constantly changing mix of video resolutions and formats as end users bring in the latest mobile devices and need to connect to the AV system. Extron scalers have the following exclusive features especially designed to support professional AV systems:
EDID compatibility between a source and display is one of the main challenges when working with HDMI, DVI, and VGA signal distribution. EDID relates to communication of a display's performance capabilities to the source connected to it. It simplifies setup in that the display "tells" the source what pixel rate and resolution it prefers and the source outputs the requested rate and resolution for the display. If this communication is interrupted following a disconnection or source switch, for example, image display can be delayed or lost completely. Also, if the source resolution does not match that of the display, the image may be fuzzy or distorted. Proper EDID management is necessary for high quality images that are accurate on a pixel-for-pixel basis.
Extron scalers feature EDID Minder®, an Extron-exclusive technology that automatically manages EDID communication between connected devices, ensuring that all sources power up properly and reliably output content for display. Another EDID management feature offered with Extron scalers is EDID Emulation, which provides internally stored EDID, at user-selectable resolutions and refresh rates, to the source device. These features ensure consistent video output, especially when multiple displays with varying resolutions are integrated into multi-source AV environments.
To reliably display protected digital video content, all relevant signal paths must be fully HDCP compliant. Otherwise, no image will appear. Also, HDCP key exchange is important if there are multiple sources and multiple displays in the system. For HDMI signals with protected content, most Extron scalers feature Key Minder, an Extron-exclusive technology that authenticates and maintains continuous HDCP encryption between input and output devices to ensure quick and reliable switching. Some scaler models also provide HDCP visual confirmation. When receiving HDCP-encrypted content from an HDMI source, the scaler outputs a full-screen green signal on any video output connected to a non-HDCP compliant display. This provides immediate visual confirmation that protected content cannot be viewed on the display.
Extron scalers featuring Auto-Image automatically detect the resolution of an incoming video signal and set the total pixels, active pixels, and active lines, as well as the horizontal and vertical starting points. These directly measured parameters ensure a proper image that is visually centered and sized correctly, saving time and effort in setting up a newly connected source, especially whenever a new laptop is connected. Auto-Image offers smooth daily operation with faster source switching by avoiding the extra step of analyzing and measuring the video signal. The user can simply touch a button on the front panel or control interface to use Auto-Image to correct for any visual imperfections that may result from a source or switcher.
Auto Input Memory and Auto Input Format Detection
Manual adjustment of size, position, and other picture settings becomes necessary in instances where Auto-Image may not recognize the true active video area, such as if the video input contains dark areas at the perimeter. Auto Input Memory detects these manual changes and automatically saves them for quick recall the next time that the same source is detected. In addition, some Extron scaler models can be set to detect the incoming signal format for each input, automatically reconfiguring itself to provide the appropriate decoding and signal processing. This Auto Input Format Detection feature can reduce the number of required outputs for a matrix switcher, lowering system cost while improving manageability.
Wide Range of Supported Resolutions and Aspect Ratio Control
To accommodate a variety of sources, Extron scalers support a wide range of resolutions plus video and computer-video formats. These supported resolutions and formats are updated regularly and include selectable output resolutions to match current and legacy display devices. Extron scalers also provide users with convenient aspect ratio management, which is advantageous as some source signals may not match the aspect ratio of the display. A Fill mode can be selected to display the output at full screen, while a Follow mode preserves the original aspect ratio of the input signal.
Internal Test Patterns
Test patterns are crucial to the proper calibration and setup of AV devices. Extron scalers offer several internal test patterns, such as a crop pattern or crosshatch. These test patterns make it easy to dial in video parameters that deliver professional quality images.
Remote Configuration and Control Options
All Extron scalers provide remote configuration and control options using RS-232 and the Extron SIS™ - Simple Instruction Set command protocol. Control via Ethernet and USB is also available on many models. The built-in Web pages and intuitive GUI-based control software provide convenient ways to access the functions necessary for high quality, professional presentations.
Extron offers several categories of scalers, which are designed to meet the needs of different applications, as well as several models of scan converters:
Video scalers are commonly used to scale standard definition video signals, such as component video, S-video, and composite video, to high resolution output rates, including HDTV. Many of the scalers in this category also offer input switching, aspect ratio conversion, and quad standard video decoding for worldwide compatibility. View Video Scalers
Video, RGB, and DVI/HDMI Scalers
Video, RGB, and DVI/HDMI scalers incorporate advanced scaling technology and are capable of scaling HDMI, DVI, RGB, component, S-video, composite, and optional SDI video formats up or down into a single output resolution, while maintaining optimum image quality. These scalers offer multiple output rates, including computer-video, plasma or LCD, and HDTV rates. View Video, RGB, and DVI/HDMI Scalers
RGB to DVI/HDMI Scalers
RGB to DVI/HDMI scalers convert incoming analog component video and RGBHV signals to DVI or HDMI signals. They are ideal for applications where DVI or HDMI-equipped displays are to be used with sources that output analog RGB computer-video, or in an environment with an existing RGB infrastructure. They can also be used in systems where consolidation of various source signals to a single, common output resolution is desired. View RGB to DVI/HDMI Scalers
Universal Signal Processors
A Universal Signal Processor combines high performance scaling, switching, scan conversion, standards conversion, and transcoding in one unit. It accepts a wide range of video input signals and transcodes them, or converts them up or down, into a number of different signal formats to meet the video signal requirements of virtually any system. View Universal Signal Processors
Annotation processors facilitate the addition of graphical elements, such as shapes, lines, arrows, and text, over live video and high resolution computer graphics. The Extron Annotator offers live annotation capabilities for overlaying graphics and text within AV presentations, plus high performance scaling and switching to simplify integration and reduce overall system cost. It features an intuitive graphical user interface so that a presenter can easily draw, point, or add text to electronic presentation materials using a touchscreen and/or a keyboard and mouse. The Annotator supports all common analog and digital video formats including RGB, DVI, and HD-SDI. View Annotation Processors
Seamless switchers provide high performance scaling of standard definition video, HDTV, and computer-video sources to high resolution output rates, including HDTV. They also offer true seamless switching between inputs with selectable transition effects for professional quality presentations. View Seamless Switchers
Scaling Matrix Switchers
Extron Scaling matrix switchers are designed for applications that require video input signals to be scaled to a common video output rate. Scaling switchers are available in two configurations: the ISM 482, which features two independent, high performance scaled outputs, each with its own selectable output rate; and the ISM 842, which features a modular, multi-switcher design that supports up to four independent output boards. View Scaling Matrix Switchers
Extron scan converters optimize high resolution computer-video signals for use on standard definition video displays. Each scan converter Extron manufactures provides a different set of features and level of functionality. View Scan Converters