Samsung S3C2451X User Manual page 619

S3C2451X RISC MICROPROCESSOR
SourceHsize
Original Input
SRC_Width = SourceHsize
SRC_Height = SourceVsize
Original Input
1
1 2
3 4
SRC_Width = SourceHsize - (WinHorOfst + WinHorOfst2)
SRC_Height = SourceVsize - (WinVerOfst + WinVerOfst2)
The other control registers of pre-scaled image size, pre-scale ratio, pre-scale shift ratio and main scale ratio are
defined according to the following equations.
If ( SRC_Width >= 64 × DST_Width ) { Exit(-1); /* Out Of Horizontal Scale Range */ }
else if (SRC_Width >= 32 × DST_Width) { PreHorRatio_xx = 32; H_Shift = 5; }
else if (SRC_Width >= 16 × DST_Width) { PreHorRatio_xx = 16; H_Shift = 4; }
else if (SRC_Width >= 8 × DST_Width) { PreHorRatio_xx = 8; H_Shift = 3; }
else if (SRC_Width >= 4 × DST_Width) { PreHorRatio_xx = 4; H_Shift = 2; }
else if (SRC_Width >= 2 × DST_Width) { PreHorRatio_xx = 2; H_Shift = 1; }
else { PreHorRatio_xx = 1; H_Shift = 0; }
PreDstWidth_xx = SRC_Width / PreHorRatio_xx;
MainHorRatio_xx = ( SRC_Width << 8 ) / ( DST_Width << H_Shift);
SourceHsize
3
2
4
: WinHorOfst, WinHorOfst2
: WinVerOfst, WinVerOfst2
Figure 23-17. Scaling scheme
Preliminary product information describe products that are in development,
for which full characterization data and associated errata are not yet available.
Specifications and information herein are subject to change without notice.
TargetHsize_xx
Scale Down
TargetHsize_xx = TargetHsize_Co or TargetHsize_Pr
DST_Width = TargetHsize_xx
DST_Height = TargetVsize_xx
TargetHsize_xx
TargetHsize_xx = TargetHsize_Co or TargetHsize_Pr
DST_Width = TargetHsize_xx
DST_Height = TargetVsize_xx
CAMERA INTERFACE
Zoom In
23-27