Waveform monitor

Waveform monitor

A waveform monitor is a special type of oscilloscope used in television applications. It is typically used to measure and display the level, or voltage, of a video signal with respect to time.

The level of a video signal usually corresponds to the brightness, or luminance, of the part of the image being drawn onto a regular video screen at the same point in time. A waveform monitor can be used to display the overall brightness of a television picture, or it can zoom in to show one or two individual lines of the video signal. It can also be used to visualize and observe special signals in the vertical blanking interval of a video signal, as well as the colorburst between each line of video.

Waveform monitors are used for the following purposes:

* To assist with the calibration of television cameras, and to "line up" multiple cameras being used at the same location in order to ensure that the same scene shot under the same conditions will produce the same results.
* As a tool to assist in telecine (film-to-tape transfer), color correction, and other video production activities
* To monitor video signals to make sure that neither the color gamut, nor the analog transmission limits, are violated.
* To diagnose and troubleshoot a television studio, or the equipment located therein.
* To assist with installation of equipment into a television facility, or with the commissioning or certification of a facility.
* In manufacturing test and research and development applications.

A waveform monitor is often used in conjunction with a vectorscope. Originally, these were separate devices; however modern waveform monitors include vectorscope functionality as a separate mode. (The combined device is simply called a "waveform monitor").

Originally, waveform monitors were entirely analog devices; the incoming (analog) video signal was filtered and amplified, and the resulting voltage was used to drive the vertical axis of a cathode ray tube. A sync stripper circuit was used to isolate the sync pulses and colorburst from the video signal; the recovered sync information was fed to a sweep circuit which drove the horizontal axis. Early waveform monitors differed little from oscilloscopes, except for the specialized video trigger circuitry. Waveform monitors also permit the use of external reference; in this mode the sync and burst signals are taken from a separate input (thus allowing all devices in a facility to be genlocked, or synchronized to the same timing source).

With the advent of digital television and digital signal processing, the waveform monitor acquired many new features and capabilities. Modern waveform monitors contain many additional modes of operation, including "picture mode" (where the video picture is simply presented on the screen, much like a television), various modes optimized for color gamut checking, support for the audio portion of a television program (either embedded with the video, or on separate inputs), eye pattern and jitter displays for measuring the physical layer parameters of serial-digital television formats, modes for examining the serial digital protocol layer, and support for ancillary data and television-related metadata such as timecode, closed captions and the v-chip rating systems.

Modern waveform monitors and other oscilloscopes have largely abandoned old-style CRT technology as well. All new waveform monitors are based on a "rasterizer", a piece of graphics hardware that duplicates the behavior of a CRT vector display, generating a raster signal. They may come with a flat-panel liquid crystal display, or they may be sold without a display, in which case the user can connect any VGA display.

Manufacturers of waveform monitors

The following companies manufacture waveform monitors:
* [http://www.hamlet.co.uk Hamlet Video International]
* [http://www.compuvideo.com Compuvideo]
* Tektronix
* [http://www.leaderusa.com Leader Instruments Corp]
* [http://www.videotek.com Videotek] , a subsidiary of Harris
* [http://www.dk-technologies.com DK-Technologies]
* [http://www.tvprogear.com/Catalog/Vector-Waveform-Rasterizer,199.aspx Used Waveform Monitors]
* [http://www.magnisystems.com Magni Systems]
* [http://www.omnitek.tv OmniTek]
* [http://www.seriousmagic.com/products/dvrack/features_monitoring.cfm Serious Magic DV Rack--a waveform monitor that runs on a laptop.]
* [http://www.transvideointl.com TRANSVIDEO]

See also

*Color suite
*Non-linear editing system
*Linear video editing
*Control room
*Television studio production control room

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Waveform monitor — A&V A device used to examine the video signal and synchronizing pulses. An oscilloscope designed especially for viewing the waveform of a video signal …   Audio and video glossary

  • waveform monitor — F/A/V a specialized oscilloscope used to display and analyze the video signals sync, luminance and chroma levels. TV Specialized oscilloscope testing device providing a graphic display of a video signal s strength. Plus, like a sophisticated… …   Audio and video glossary

  • Waveform Monitor — VP A hardware device or software plug in that allows the camera technician to accurately adjust the brightness and contrast with either lighting or the camera s internal white and black levels …   Audio and video glossary

  • waveform monitor —    A specially designed oscilloscope display that graphically shows waveforms …   IT glossary of terms, acronyms and abbreviations

  • Waveform — means the shape and form of a signal such as a wave moving in a solid, liquid or gaseous medium.In many cases the medium in which the wave is being propagated does not permit a direct visual image of the form. In these cases, the term waveform… …   Wikipedia

  • Waveform viewer — A waveform viewer is a software tool for viewing the signal levels of either a digital or analog circuit design.John Bergeron, Writing Testbenches: Functional verification of HDL Models , Kluwer Academic Publishers, 2000] Waveform viewers comes… …   Wikipedia

  • waveform — The form of a pulse; e.g., an arterial pressure or displacement wave; or of the pacemaker pulse as demonstrated on the oscilloscope under a specified load. pressure w. a graphic …   Medical dictionary

  • Medical monitor — as used in anesthesia A medical monitor or physiological monitor or display, is an electronic medical device used in medical monitoring that displays the monitored data, and may or may not have the ability to transmit the data on a monitoring… …   Wikipedia

  • Oscilloscope types — This is a subdivision of the Oscilloscope article, discussing the various types and models of oscilloscopes in greater detail. Contents 1 Cathode ray oscilloscope (CRO) 1.1 Dual beam oscilloscope 2 Analog storage oscilloscope …   Wikipedia

  • Vectorscope — A vectorscope is a special type of oscilloscope used in both audio and video applications. Whereas an oscilloscope or waveform monitor normally displays a plot of signal vs. time, a vectorscope displays an X Y plot of two signals, revealing… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.