Coordinated Video Timings (CVT; ''VESA-2013-3 v1.2'') is a standard by
VESA which defines the timings of the
component video signal. Initially intended for use by
computer monitor
A computer monitor is an output device that displays information in pictorial or textual form. A discrete monitor comprises a visual display, support electronics, power supply, housing, electrical connectors, and external user controls.
The ...
s and
video card
A graphics card (also called a video card, display card, graphics adapter, VGA card/VGA, video adapter, display adapter, or mistakenly GPU) is an expansion card which generates a feed of output images to a display device, such as a computer m ...
s, the standard made its way into consumer
televisions.
The parameters defined by standard include
horizontal blanking and
vertical blanking interval
In a raster scan display, the vertical blanking interval (VBI), also known as the vertical interval or VBLANK, is the time between the end of the final visible line of a frame or field and the beginning of the first visible line of the next fra ...
s,
horizontal frequency and
vertical frequency (collectively,
pixel clock rate or video
signal bandwidth), and
horizontal/
vertical sync polarity.
The standard was adopted in 2002 and superseded the
Generalized Timing Formula.
Reduced blanking
CVT timings include the necessary pauses in picture data (known as "blanking intervals") to allow CRT displays to reposition their electron beam at the end of each
horizontal scan line, as well as the
vertical repositioning necessary at the end of each
frame. CVT also specifies a mode ("CVT-R") which significantly reduces these blanking intervals (to a period insufficient for CRT displays to work correctly) in the interests of saving video signal bandwidth when modern displays such as
LCD monitor
A thin-film-transistor liquid-crystal display (TFT LCD) is a variant of a liquid-crystal display that uses thin-film-transistor technology to improve image qualities such as addressability and contrast. A TFT LCD is an active matrix LCD, in cont ...
s are being used, since such displays typically do not require these pauses in the picture data.
In revision 1.2, released in 2013, a new "Reduced Blanking Timing Version 2" mode was added which further reduces the horizontal blanking interval from 160 to 80 pixels, increases pixel clock precision from ±0.25 MHz to ±0.001 MHz, and adds the option for a 1000/1001 modifier for ATSC/NTSC video-optimized timing modes (e.g. 59.94 Hz instead of 60.00 Hz or 23.976 Hz instead of 24.000).
CEA-861-H will introduce RBv3.
Bandwidth
See also
*
Extended display identification data
References
External links
VESA free standards- includes free CVT 1.2 timings spreadsheet
Video signal
{{computer-stub