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34 Chapter 4: Hardware reference
Gain
Digitizing
component
Video decoders
The acquisition section has 16 standard video decoders. In addition to digitizing
video, these decoders feature internal filtering and automatic gain control.
The automatic gain control (AGC) allows the video signal input range to be
optimized before being digitized. You can, however, disable the AGC and set the
gain manually, using the MdigControl() function, with
M_GRAB_AUTOMATIC_INPUT_GAIN
M_GRAB_INPUT_GAIN
The multi-standard video decoders can convert analog composite (CVBS) video
in NTSC/PAL format, to digitized video in YUV16 (4:2:2) format.
Each decoder supports the following video timing
P i x e l s a m p l i n g r a t e ( M H z )
Y c o m p o n e n t s a m p l i n g r a t e ( M H z )
U a n d V c o m p o n e n t s ( M H z )
D i g i t i z i n g c o m p o n e n t s a m p l i n g r a t e ( M H z )
F i e l d r a t e ( H z )
P i x e l / l i n e ( p i x e l s )
A c t i v e p i x e l / l i n e ( p i x e l s )
A c t i v e l i n e s / f r a m e ( l i n e s )
L i n e r a t e ( K H z )
Video capture controller
Once the analog video has been converted to digitized video, it enters a component
called the video capture controller.
The video capture controller accepts all data signals provided by the decoders and
transfers them to acquisition memory. It is also capable of performing vertical and
horizontal flipping of the image during capture.
set to
M_DISABLE
set to any integer value from 0 to 255.
and
settings:
S q u a r e p i x e l v i d e o f o r m a t s
N T S C
1 2 . 2 7
1 2 . 2 7
6 . 1 4 e a c h
7 . 3 8 e a c h
2 4 . 5 4
6 0
7 8 0
6 4 0
4 8 0
1 5 . 7 3 4
P A L
1 4 . 7 5
1 4 . 7 5
2 9 . 5
5 0
9 4 4
7 6 8
5 7 6
1 5 . 6 2 5
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