
Bt2166
Graphics/Video Controller
Brooktree
4
PRODUCT DESCRIPTION
Introduction
L2166_A
The Bt2166 rendering engine provides xed-color alpha-blending in addition to
texture alpha-blending to control the transparency of an object to the underlying
scene, allowing realistic rendering of translucent surfaces. Alpha-blending is also
used to create atmospheric effects such as fogging and depth queueing. Lighting
models can be applied using either at or Gouraud shading. Color dithering is also
available to minimize pixelization and contouring effects in object shading caused
by use of limited color resolution and can be applied to both palletized and 16-bit
images.
The Bt2166 delivers high-performance acceleration for 3D games under Win-
dows 95 with Microsoft’s Direct3D API and offers direct support for the BRender
and OpenGL 3D graphics APIs.
High-Performance 2D
Graphics Acceleration
The 2D GUI engine optimizes application performance under Windows 95 Direct-
Draw. The 2D GUI engine incorporates a 64KB command queue enabling full
overlap of application and GUI command execution. It also includes transparent
BLT support, a 2 operand BitBLT engine, text BLT, line drawing, solid/pattern ll,
and color expansion.
Video Playback and
Display
The Bt2166 supports advanced video playback hardware acceleration and video
display processing through color space conversion, scaling, and TrueView technol-
ogy for interlaced video source processing. DirectVideo acceleration of software
video codecs is provided by YCrCb to RGB color conversion and high-quality im-
age upscaling. Native video source formats can be scaled up to 1024 x 768 full
screen resolution using an advanced 2-dimensional video lter. Video scaling is
implemented using 3-tap horizontal and 3-tap vertical interpolation ltering. Video
quality is further enhanced with advanced image ltering to improve picture sharp-
ness. The result is a high-resolution PC video image display which rivals the del-
ity of high end TVs.
The Bt2166 enhances TrueView’s technology for interlaced-to-progressive scan
conversion. TrueView enables the display of full CCIR601 resolution video from
an MPEG2 video decoder or Bt829A VideoStream decoder without intermediate
processing, hence, preserving the inherent quality of the YCrCb 4:2:2 video stream
delivered by the decoder. TrueView uses vertical scaling and ltering and the lock-
ing of graphics frame timing to the video source input eld timing to overcome vis-
ible scan conversion artifacts, such as intereld motion and tearing.
The hardware can support two video windows with double-buffering. Mixing of
video and graphics can be implemented using either color keying or chroma key-
ing techniques. This technology directly addresses the requirements of high-del-
ity video display on progressive monitors in the PC-TV consumer product
category. The hardware can support two video windows with double-buffering.
Mixing of video and graphics can be implementing using either color keying or
chroma keying techniques.
A exible video peripheral interface allows a wide range of MPEG video de-
coder hardware and the Brooktree Bt829A VideoStream decoder to be gluelessly
attached to the Bt2166. The Bt2166 is tailored for use with popular MPEG2 video
decoder chips for digital satellite TV and DVD movie player applications, and with
the Bt829A for analog TV, Intercast, and video phone applications.