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via - VIA unichrome graphics driver
via is an Xorg driver for VIA chipsets with onboard unichrome
The via driver supports the VIA CLE266, KM400/KN400 chipsets,
including 2D acceleration and the Xv video overlay extensions. Flat panel,
TV and VGA outputs are supported.
K8M800/K8N800, PM8X0 and CN400 support
is still under development.
Direct rendering 3D is available using experimental
drivers in Mesa, www.mesa3d.org. Also there is an XvMC client library for
hardware MPEG1 / MPEG2 decoding acceleration available on the CLE266 and
K8M/N800 chipsets that uses the Direct Rendering Infrastructure, DRI. The
XvMC client library implements a nonstandard "VLD" extension to the XvMC
standard. The current Direct Rendering Manager Linux kernel module is available
Please refer to xorg.conf(5x)
for general configuration details. This section only covers configuration
details specific to this driver.
The following driver options are supported
Unichromes tend to be paired with several
different TV Encoders.
- Option "NoAccel" "boolean"
- Disable or enable acceleration. Default: acceleration
- Option "HWCursor" "boolean"
- Disable or enable use of hardware
cursors. The default is enabled.
- Option "SWCursor" "boolean"
- Disable or enable
the use of a software cursor. The default is disabled.
- Option "ShadowFB"
- Use a shadow frame buffer. This is required when rotating the
display, but otherwise defaults to disabled.
- Option "VideoRAM" "boolean"
- Override the VideoRAM auto detection. This should never be needed.
- Rotate the display either clockwise ("CW") or counter
clockwise ("CCW"). Rotation is only supported unaccelerated.
- Option "ActiveDevice"
- Specify the active device combination. Any string containing "CRT",
"LCD", "TV" should be possible. The default is to use what is detected. The
driver is currently unable to use LCD and TV simultaneously, and will favour
- Option "LCDDualEdge" "boolean"
- Use dual edge mode to set the LCD.
- Option "Center" "boolean"
- Disable or enable image centering on DVI displays.
- Option "PanelSize" "string"
- Specify the size (width x height) of the LCD
panel attached to the system. Sizes 640x480, 800x600, 1024x768, 1280x1024,
and 1400x1050 are supported.
- Option "TVDotCrawl" "boolean"
- Disable or enable
- Option "TVDeflicker" "integer"
- Specify deflicker setting for TV
output. Valid values are 0,1,2 0) No deflicker, 1) 1:1:1 deflicker, 2) 1:2:1
- Option "TVType" "string"
- Specify TV output format. The driver
currently supports "NTSC" and "PAL" timings only.
- Option "TVOutput" "string"
- Specify which TV output to use. The driver supports "S-Video", "Composite",
"SC", "RGB" and "YCbCr" outputs. Note that on some EPIA boards the composite
video port is shared with audio out and jumper selected.
- Option "DisableVQ"
- Disable or enable the use of VQ. VQ is enabled by default.
- Set DRI Xinerama mode. Currently unsupported.
- Enable the AGP DMA functionality in DRM. This requires
that DRI is enabled and will force 2D acceleration to use AGP DMA. The XvMC
DRI client will also make use of this to consume much less CPU.
- With this option on, 2D acceleration will not use
AGP DMA even if it is enabled.
- Option "VBEModes" "boolean"
- The driver will
set modes using BIOS similar to the way the vesa driver does. This is the
default behaviour for Unichrome Pro in panel mode, which is otherwise not
supported. Use this option only when the driver does not support your particular
driver is not fully 64 bit clean. In particular, 3D acceleration, XvMC and
VBEModes do not work properly in 64-bit mode.
Authors include: ...
- VIA Technologies VT1621
- Untested as no combination
with Unichrome is known or available. Supports the following normal modes:
"640x480" and "800x600". Use "640x480Over" and "800x600Over" for vertical
overscan. These modes are made available by the driver and modelines provided
in xorg.conf will be ignored.
- VIA Technologies VT1622, VT1622A, VT1623
the following modes: "640x480", "800x600", "1024x768", "848x480", "720x480"
(NTSC only) and "720x576" (PAL only). Use "640x480Over", "800x600Over",
"1024x768Over", "848x480Over", "720x480Over" (NTSC) and "720x576Over" (PAL)
for vertical overscan. The modes "720x480Noscale" (NTSC VT1622 only) and
"720x576Noscale" (PAL VT1622 and VT1622a only) provide cleaner TV output
(unscaled with only minimal overscan). These modes are made available by
the driver and modelines provided in xorg.conf will be ignored.
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