adv7322 Analog Devices, Inc., adv7322 Datasheet - Page 60

• Manufacturer Part Number: adv7322
• Description: Multiformat 11-bit Hdtv Video Encoder
• Manufacturer: Analog Devices, Inc.

ADV7322
DNR MODE CONTROL
[Address 0x65, Bit 4]
This bit controls the DNR mode selected. Logic 0 selects DNR
mode; Logic 1 selects DNR sharpness mode.
DNR works on the principle of defining low amplitude, high
frequency signals as probable noise and subtracting this noise
from the original signal.
In DNR mode, it is possible to subtract a fraction of the signal
that lies below the set threshold, assumed to be noise, from the
original signal. The threshold is set in DNR Register 1.
When DNR sharpness mode is enabled, it is possible to add a
fraction of the signal that lies above the set threshold to the
1.0
0.8
0.6
0.4
0.2
0
0
FILTER C
FILTER D
1
Figure 80. DNR Input Select
2
FREQUENCY (Hz)
100 IRE
FILTER B
0 IRE
3
FILTER A
LUMA CHANNEL WITH
ACTIVE VIDEO EDGE
DISABLED
4
5
Figure 81. Example of Active Video Edge Functionality
6
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87.5 IRE
12.5 IRE
100 IRE
50 IRE
0 IRE
original signal, since this data is assumed to be valid data and
not noise. The overall effect is that the signal will be boosted
(similar to using Extended SSAF filter).
BLOCK OFFSET CONTROL
[Address 0x65, Bits 7 to 4]
Four bits are assigned to this control, which allows a shift of the
data block of 15 pixels maximum. Consider the coring gain
positions fixed. The block offset shifts the data in steps of one
pixel such that the border coring gain factors can be applied at the
same position regardless of variations in input timing of the data.
SD ACTIVE VIDEO EDGE
[Subaddress 0x42, Bit 7]
When the active video edge feature is enabled, the first three
pixels and the last three pixels of the active video on the luma
channel are scaled so that maximum transitions on these pixels
are not possible. The scaling factors are ×1/8, ×1/2, and ×7/8.
All other active video passes through unprocessed.
SAV/EAV STEP EDGE CONTROL
The ADV7322 has the capability of controlling fast rising and
falling signals at the start and end of active video to minimize
ringing.
An algorithm monitors SAV and EAV and determines when the
edges are rising or falling too fast. The result is reduced ringing
at the start and end of active video for fast transitions.
Subaddress 0x42, Bit 7 = 1, enables this feature.
LUMA CHANNEL WITH
ACTIVE VIDEO EDGE
ENABLED
Preliminary Technical Data