xvidtune

xvidtune [ -display
display> ] [ -geometry
geometry> ] [ -show ] [ -prev ] [ -next ] [ -test ] [ -probe ] [ -sync ] [ -exit ] [ -f | -fullscreen ] [ -s | -save ] [ -t | -timeout ]

-display
    Specifies the X display to connect to.

-geometry
    Sets the initial window geometry of the xvidtune application.

-show
    Prints the current video mode settings to standard output in a format suitable for an X server configuration file (e.g., xorg.conf).

-prev
    Switches the X server to the previous video mode in its internal list of available modes.

-next
    Switches the X server to the next video mode in its internal list of available modes.

-test
    Applies the currently adjusted mode parameters for a brief period to allow visual evaluation, then reverts to the original mode. Typically used with -timeout.

-probe
    Attempts to probe and discover additional video modes supported by the display hardware or driver. Functionality varies by driver.

-sync
    Synchronizes xvidtune's internal state with the X server's currently active video mode.

-exit
    Immediately exits the xvidtune program.

-f, -fullscreen
    Launches xvidtune in fullscreen mode, occupying the entire screen.

-s, -save
    Saves the currently applied video mode settings to a user-specific configuration file, typically ~/.xvidtune, which can later be used to update the main X server configuration.

-t, -timeout
    Sets the duration in seconds for the -test option before the video mode automatically reverts.

xvidtune is a graphical user interface utility for the X Window System that allows users to fine-tune and dynamically adjust the video mode timings of the X server. It provides an interactive way to modify parameters such as dot clock, horizontal and vertical synchronization timings, and display dimensions. This tool was historically invaluable for optimizing display output, especially on CRT monitors or with custom display setups, by allowing live adjustments to eliminate screen artifacts, correct screen position or size, and achieve optimal refresh rates.

While its primary use case has diminished with modern display technologies and automatic EDID (Extended Display Identification Data) detection, xvidtune still offers a low-level interface to the X server's video driver. It can be particularly useful in niche scenarios or when dealing with older hardware that lacks proper EDID information, or when precise manual calibration is required. It reads the current video mode information and presents it via sliders and input fields, allowing users to test changes instantly before deciding to save them to the X server's configuration.

xvidtune's direct video timing manipulation capabilities are less relevant for modern graphics drivers and displays that rely heavily on RandR (XRandR) and EDID for mode negotiation.

Incorrectly configured video timings can potentially damage older CRT monitors or cause display instability. Users should proceed with caution.

Saving changes typically writes to a user-specific file (~/.xvidtune) and often requires manual integration into the main X server configuration (e.g., /etc/X11/xorg.conf or a snippet within /etc/X11/xorg.conf.d/) and a subsequent X server restart to take permanent effect.

Permissions are critical; xvidtune often needs elevated privileges or specific policykit rules to interact directly with the X server's mode database.

xvidtune is most beneficial in specific scenarios such as:
1. Adjusting older CRT monitors to perfectly fit the screen, correct overscan/underscan issues, or achieve higher refresh rates.
2. Troubleshooting displays with poor or missing EDID information.
3. Fine-tuning projector outputs or custom embedded display panels where standard resolutions or timings are not optimal.

The output from xvidtune -show can be directly copied into the 'Monitor' or 'Screen' sections of your xorg.conf file (or a relevant snippet in /etc/X11/xorg.conf.d/) as a 'Modeline'. This allows the X server to use your custom timing permanently after a restart. The -save option typically writes to ~/.xvidtune, which serves as a temporary storage and may require manual transfer to the system-wide configuration.

xvidtune originated as part of the XFree86 project, which was the dominant open-source implementation of the X Window System before X.Org took over. It was developed in an era when manual configuration of video modes via 'Modelines' in the X server configuration file (XF86Config, later xorg.conf) was a common necessity. Its introduction provided a much-needed interactive graphical interface for fine-tuning these complex timing parameters without requiring constant manual editing and X server restarts.

While still available in many modern Linux distributions, its practical utility has significantly declined since the widespread adoption of EDID-based automatic monitor detection and the more flexible RandR (XRandR) extension, which allows dynamic resolution and display layout changes at a higher level of abstraction.

xrandr(1), Xorg(1), xdpyinfo(1), cvt(1)