Focus Enhancements FS456 Data Sheet

Page of 41
FS453/4 AND FS455/6 
 
DATA SHEET: HARDWARE REFERENCE 
JANUARY, 2005, VERSION 3.0 
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.