FOCUS Enhancements FS453 - Manual (Page 6)

FS453/4 AND FS455/6 DATA SHEET: HARDWARE REFERENCE
JANUARY, 2005, VERSION 3.0 6 COPYRIGHT ©2003-4 FOCUS ENHANCEMENTS, INC.
FOCUS Enhancements Semiconductor
2.1.1 Input to Output Conversion Matrix
Table 1 below lists some commonly used input modes and the correspondingly supported output modes.
SDTV input dimensions are completely configurable, subject only to pixel clock range limitations.
Output Configuration Input Configuration
SDTV HDTV
Pixels Lines NTSC
@59.94Hz
PAL
@50Hz
480p
@60Hz
720p
@60Hz
1080i
@60Hz
640 - 720 480 ∗ ∗ ∗ (a)
640 - 720 576 ∗ ∗
800 600 ∗ ∗
1024 768 ∗ ∗
1280 720 ∗ (b) ∗ (b) ∗ (a)
1920 1080 ∗ (c)
Table 1: Input to Output Conversion Matrix
Notes:
(a) No scaling supported
(b) Subject to the maximum 150 MHz pixel rate
(c) No scaling or interlacing supported, input data must be interlaced
2.2 Color Space Converter
The programmable Color Space Converter receives either RGB or YCrCb data from the input port. If the
data is RGB, it is converted to YCrCb using programmable coefficients. Each of the Y, Cr, and Cb
components can then be independently scaled in amplitude with programmable multipliers. This
programmability supports both SDTV and HDTV color space matrices.
2.3 Patented 2D Scaler
The Patented 2D Scaler receives data from the Color Space Converter. It performs vertical (up or down)
scaling based on the value programmed in the VSC (Vertical Scaling Coefficient) register, offset 06h. It
performs horizontal (down) scaling based on the downscale value programmed in the HSC (Horizontal
Scaling Coefficient) register, offset 08h.
Because different video standards call for different numbers of lines and different numbers of pixels per
line, scan converters add or subtract lines and areas to fit graphics images onto different sizes of TV
screens. Most scan converters use simple line-dropping algorithms and fixed aspect ratios.
Unfortunately, these techniques can introduce shape-distorting artifacts and surround the actual image
with blank areas.
The FS453, however, uses patented technology that can scale the graphics image without creating
artifacts. The patented 2D Scaler can independently upscale or downscale an image in both the
horizontal (pixels) and vertical (lines) directions. Its scaling functions provide equal weight to all pixels
and lines in the source material for all scaling factors.
This allows users to perfectly fit the graphics image
to their TV screens without adding scaling artifacts or large blank borders.