JG82852GMSL7VP Datasheet, PDF (136/176 Pages) Intel Corporation – Intel® 852GM/852GMV Chipset Intel® 852GM/852GMV Chipset Hub (GMCH)

Functional Description
5.4.6.3.
R
Popup Color Formats
Source color data for the popup is in an indexed format. Indexed data uses the entries in the four-entry
cursor palette to convert the two-bit index to a true color format before being passed to the blenders.
Blending of color data is only supported with data of the same format.
5.4.7.
5.4.7.1.
5.4.7.2.
5.4.7.3.
5.4.7.4.
5.4.7.5.
5.4.7.6.
Overlay Plane
The overlay engine provides a method of merging either video capture data (from an external Video
Capture device) or data delivered by the CPU, with the graphics data on the screen.
Multiple Overlays (Display C)
A single overlay plane and scalar is implemented. This overlay plane can be connected to the primary
display, secondary display or in bypass mode. In the default mode, it appears on the primary display.
The overlay may be displayed in a multi-monitor scenario for single-pipe simultaneous displays only.
Picture-in-Picture feature is supported via software through the arithmetic stretch blitter.
Source/Destination Color/Chromakeying
Overlay source/destination chromakeying enables blending of the overlay with the underlying graphics
background. Destination color-/chromakeying can be used to handle occluded portions of the overlay
window on a pixel-by-pixel basis that is actually an underlay. Destination color keying supports a
specific color (8-bit or 15-bit) mode as well as 32-bit alpha blending.
Source color/chromakeying is used to handle transparency based on the overlay window on a pixel-by-
pixel basis. This is used when “blue screening” an image to overlay the image on a new background
later.
Gamma Correction
To compensate for overlay color intensity loss, the overlay engine supports independent gamma
correction. This allows the overlay data to be converted to linear data or corrected for the display device
when not blending.
YUV to RGB Conversion
The format conversion can be bypassed in the case of RGB source data.
Color Control
Color control provides a method of changing the color characteristics of the pixel data. It is applied to
the data while in YUV format and uses input parameters such as brightness, saturation, hue (tint) and
contrast. This feature is supplied for the overlay only and works in YUV formats only.
Dynamic Bob and Weave
Interlaced data that originates from a video camera creates two fields that are temporally offset by 1/60
of a second. There are several schemes to de-interlace the video stream: line replication, vertical
filtering, field merging, and vertical temporal filtering. Field merging takes lines from the previous field
and inserts them into the current field to construct the frame – this is known as Weaving. This is the best
solution for images with little motion; however, showing a frame that consists of the two fields will have
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Intel^® 852GM/852GMV Chipset GMCH Datasheet