Generalized Timing Formula
Encyclopedia
Generalized Timing Formula is a standard by VESA
which defines exact parameters of the component video signal
for analog VGA display interface.
The parameters defined by the standard include horizontal blanking (retrace) and vertical blanking intervals, horizontal frequency
and vertical frequency
(collectively, pixel clock rate or video signal bandwidth), and horizontal/vertical sync polarity. These parameters are used by the XFree86 Modeline
, for example. This standard is available from VESA for .
The standard was adopted in 1999, and was superseded by the Coordinated Video Timings
specification in 2002.
VESA
VESA is an international standards body for computer graphics founded in 1989 by NEC Home Electronics and eight other video display adapter manufacturers.VESA's initial goal was to produce a standard for 800×600 SVGA resolution video displays...
which defines exact parameters of the component video signal
Component video
Component video is a video signal that has been split into two or more component channels. In popular use, it refers to a type of component analog video information that is transmitted or stored as three separate signals...
for analog VGA display interface.
The parameters defined by the standard include horizontal blanking (retrace) and vertical blanking intervals, horizontal frequency
Horizontal scan rate
Horizontal scan rate, or horizontal frequency, usually expressed in kilohertz, is the frequency at which a CRT moves the electron beam from the left side of the display to the right and back, and therefore describes the number of horizontal lines displayed per second...
and vertical frequency
Refresh rate
The refresh rate is the number of times in a second that a display hardware draws the data...
(collectively, pixel clock rate or video signal bandwidth), and horizontal/vertical sync polarity. These parameters are used by the XFree86 Modeline
XFree86 Modeline
A modeline is a configuration line in xorg.conf or the XFree86 configuration file that provides information to the X server about a connected computer monitor or television and how to drive it at a specified display resolution...
, for example. This standard is available from VESA for .
The standard was adopted in 1999, and was superseded by the Coordinated Video Timings
Coordinated Video Timings
Coordinated Video Timings is a standard by VESA which defines the timings of the component video signal. Initially intended for use by computer monitors and video cards, the standard made its way into consumer televisions....
specification in 2002.
External links
- VESA: spreadsheet for calculating parameters of GTF signal (registration required, but free)