Texas Instruments DM38x DaVinci, Руководство пользователя

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Use forward difference to iteratively evaluate quadratic
equation:
y = a*x
2
+ bx + c for x = 0,1,2 … W-1
Initialize values:
x = 0
y = a*x
2
+ b*x + c
D x = 1
y+ D D D y = a*(x+ x) +b*(x+
2
x)+c
D y = (y+ 1st diff D
y)– y
D y = 2*a* x*x + a*( x) + b* x = a+b D D D
2
D
2
y = y(x+ x)- y(x) 2nd diff D D D
D
2
y = 2*a*( x) D
2
= 2*a
Iterate and generate sequence of y:
y = c
for n=1 to W
y += D y
D y += y D
2
End
Configuration registers
y is acc and D y is nlin_acc
nlin_acc_init = K
nlin_acc_inc = 2*a = 2*K
720
480
120 120
left src
inner col right src
inner col
src
1920
1080
420 420
left tar
inner col right tar
inner col
tar
col
src
col
src col = K * (tar col)
2
K = left src inner col / (left tar inner col)
2
tar
right src inner col
left src inner col
srcWi=
480
tarWi=
1080
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Internal Modules
199 SPRUHI7A – December 2012 – Revised June 2016
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High-Definition Video Processing Subsystem (HDVPSS)
1.2.11.2.4.3 Nonlinear Horizontal Scaling
The horizontal scaler supports non-linear scaling to maintain the same aspect ratio for inner picture while
stretching picture edges to fill the screen when displaying a 4x3 picture onto a 16x9 display. When setting
up a non-linear scaling application, the inner picture is defined as the center square portion of the image
with width and height equal to the height of the source image. Remaining side regions are then scaled
non-linearly.
Figure 1-149 shows a non-linear scaling case:
Figure 1-149. Non-linear Scaling Example