Samsung S5PC110 Manual page 1579

S5PC110_UM
8.4.2 THE IDEA OF POLY-PHASE FILTERING IN VIDEO PROCESSOR
shows basic concept of poly-phase filtering in video processor in case of 4-tap vertical luminance filter.
Figure 8-9
Pixels highlighted in grey color are from decoded pictures and used to interpolate the dotted pixels, which are
transferred to MIXER. The vertical positions of pixels to be interpolated are calculated with
VP_SRC_V_POSITION and VP_V_RATIO. Once the vertical position is calculated, the nearest pixel phase (with
1/16 resolution) and which pixels are used for interpolation are decided.
V_RATIO
Current Interpolated Pixel
with
V_RATIO
Next Interpolated Pixel
with
V_RATIO
N Line
th
N+1
th
Y0, Y1, Y2, Y3
N+2
th
Y0, Y1, Y2, Y3
N+3
th
N+4
th
Figure 8-9
SRC_V_POS
0/16 phase
Line
4/16 phase
SRC_V_POS + 1*V_RATIO
8/16 phase
12/16 phase
16/16 phase
Line
SRC_V_POS + 2*V_RATIO
Line
SRC_V_POS + 3*V_RATIO
Line
4-Tap Vertical Poly-phase Filter
8 7BVIDEO PROCESSOR
Y0
Y1 Y0
Y2 Y1
Y3 Y2
Y3
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