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NVTV(1x) User Commands NVTV(1x)


nvtv — GUI to control TV output hardware settings


nvtv is a small utility to control the output modes of TV-OUT encoders on many Nvidia-based video cards, as well as on the Voodoo3 video card. Use this with care, you may damage your hardware with a wrong set of options! You can find more detailed descritiptions of each option in the file /usr/share/doc/nvtv/USAGE.gz .


Print help message
X server to contact
TV off, switch to monitor
TV on
Color bars
Calculate and print register values
Fetch current mode (use only for printing)
List available modes on stdout. Must be combined with -T if hardware is not accessible. Can be combined with -S. Fields are separated by tabs, and contain TV system, resolution, size, overscan compenstation percentage, and aspect in that order.
Select resolution (screen size in pixels)
Select overscan compensation percentage (as float)
Select size (for predefined modes)

Select the TV system. PAL-X is a pseudo-PAL system with slightly different subcarrier frequencies.


Select the video connecter. CONVERT compensates for cheap SVideo to composite converter cables that don't merge both lines. FBAS and SVHS are still recognized for compatibility reasons.

Select the encoder chip by I2C bus and address, or by type (BROOKTREE, CONEXANT, NVIDIA, CHRONTEL1,C HRONTEL2, PHILIPS1, PHILIPS2). CHRONTEL and PHILIPS default to CHRONTEL1 and PHILIPS1.
Graphics card pci address (hexadecimal), as given by lspci.
Select window by numerical id
Select window by name
Center selected window
Switch X mode
Use first head
Use second head (if available)
Query status of display (monitor, TV, flatpanel)
Probe and print system information
Enable usage of /dev/nv* devices
Always use gui
(only for debugging)
(only for debugging)
Specify the setting name with value val (see below).


A complete list of all available settings can be obtained with the option -h. The values may be adjusted according to the capabilities of the TV encoder chip, and not all encoders support all settings. Also, equal values may have different effects for different encoder chips.

Settings include

from -100 (percent) to 100 (percent).
from -100 (percent) to 100 (percent).
from -50 (percent) to 50 (percent). This setting and the two following settings change the TV signal directly and should be used carefully. Extreme values may degrade the signal up to the point where it cannot be properly displayed anymore.
from -50 (percent) to 50 (percent).
from -50 (percent) to 50 (percent).
from -60 (degrees) to 60 (degrees).
from -60 (degrees) to 60 (degrees).
Flicker filter, from 0 (percent) to 100 (percent).
Adaptive flicker filter, from 0 (percent) to 100 (percent).
Bandwidth filter for the luminance channel, from 0 (percent) to 100 (percent). Larger bandwidth gives more horizontal detail, but is also more sensitive to noise.
Bandwidth filter for the chrominance channel, from 0 (percent) to 100 (percent).
Sharpness (or text enhancement) filter, from 0 (percent) to 100 (percent).
Cross color reduction filter, from 0 (percent) to 100 (percent).
Flag to dislay the image both on the monitor and the TV. Not supported for all modes.
Flag to display TV image in monochrome.
Flag to display TV image in non-interlaced mode. Reduces vertical detail, but decreases flicker.
Flag to enable macrovision.
Flag to let the color carrier generator run free.
Flag to fix the color format for Philips encoder chips.
Flag to adjust cursor when in shared view dualhead mode.
Flag to adjust the TV viewport by cursor when in shared view dualhead mode.
Flag to adjust the TV viewport by the monitor viewport when in shared view dualhead mode.


The full documentation for nvtv is located in /usr/share/doc/nvtv/ directory.


Dirk Thierbach

Eduard Bloch, for the the Debian system.

Permission is granted to copy, distribute and/or modify this document under the terms of the BSD License.

March 2002 User Commands