EVAL-ADV7320EB AD [Analog Devices], EVAL-ADV7320EB Datasheet - Page 58

• Manufacturer Part Number: EVAL-ADV7320EB
• Description: Multiformat 216 MHz Video Encoder with Six NSV 12-Bit DACs
• Manufacturer: AD [Analog Devices]

ADV7320/ADV7321
CORING GAIN BORDER
[Address 0x63, Bits 3 to 0]
These four bits are assigned to the gain factor applied to border
areas. In DNR mode, the range of gain values is 0 to 1 in
increments of 1/8. This factor is applied to the DNR filter
output, which lies below the set threshold range. The result is
then subtracted from the original signal.
In DNR sharpness mode, the range of gain values is 0 to 0.5 in
increments of 1/16. This factor is applied to the DNR filter
output, which lies above the threshold range. The result is
added to the original signal.
CORING GAIN DATA
[Address 0x63, Bits 7 to 4]
These four bits are assigned to the gain factor applied to the luma
data inside the MPEG pixel block. In DNR mode, the range of
gain values is 0 to 1 in increments of 1/8. This factor is applied
to the DNR filter output, which lies below the set threshold
range. The result is then subtracted from the original signal.
Y DATA
Y DATA
INPUT
INPUT
DNR MODE
NOISE
SIGNAL PATH
DNR
SHARPNESS
MODE
NOISE
SIGNAL PATH
INPUT FILTER
INPUT FILTER
MAIN SIGNAL PATH
MAIN SIGNAL PATH
BLOCK
BLOCK
Figure 78. DNR Block Diagram
< THRESHOLD?
> THRESHOLD?
BLOCK SIZE CONTROL
CORING GAIN BORDER
CORING GAIN BORDER
BLOCK SIZE CONTROL
OUTPUT
OUTPUT
CORING GAIN DATA
CORING GAIN DATA
FILTER
FILTER
BLOCK OFFSET
FILTER OUTPUT
< THRESHOLD
BLOCK OFFSET
FILTER OUTPUT
BORDER AREA
BORDER AREA
DNR CONTROL
DNR CONTROL
> THRESHOLD
GAIN
GAIN
+
+
–
+
SUBTRACT SIGNAL
IN THRESHOLD
RANGE FROM
ORIGINAL SIGNAL
ADD SIGNAL
ABOVE
THRESHOLD
RANGE FROM
ORIGINAL SIGNAL
DNR OUT
DNR OUT
Rev. 0 | Page 58 of 88
In DNR sharpness mode, the range of gain values is 0 to 0.5 in
increments of 1/16. This factor is applied to the DNR filter
output, which lies above the threshold range. The result is
added to the original signal.
DNR THRESHOLD
[Address 0x64, Bits 5 to 0]
These six bits are used to define the threshold value in the range
of 0 to 63. The range is an absolute value.
BORDER AREA
[Address 0x64, Bit 6]
When this bit is set to Logic 1, the block transition area can be
defined to consist of four pixels. If this bit is set to Logic 0, the
border transition area consists of two pixels, where one pixel
refers to two clock cycles at 27 MHz.
BLOCK SIZE CONTROL
[Address 0x64, Bit 7]
This bit is used to select the size of the data blocks to be
processed. Setting the block size control function to Logic 1
defines a 16 pixel × 16 pixel data block, and Logic 0 defines an
8 pixel × 8 pixel data block, where one pixel refers to two clock
cycles at 27 MHz.
DNR INPUT SELECT CONTROL
[Address 0x65, Bits 2 to 0]
Three bits are assigned to select the filter, which is applied to the
incoming Y data. The signal that lies in the pass band of the
selected filter is the signal that will be DNR processed. Figure 81
shows the filter responses selectable with this control.
DNR27 – DNR24 = 0x01
720 × 485 PIXELS
(NTSC)
APPLY DATA
CORING GAIN
O X X X X X X O O X X X X X X O
O X X X X X X O O X X X X X X O
O X X X X X X O O X X X X X X O
Figure 79. DNR Offset Control
Figure 80. DNR Border Area
8 × 8 PIXEL BLOCK
APPLY BORDER
CORING GAIN
BORDER DATA
2-PIXEL
8 × 8 PIXEL BLOCK
OFFSET CAUSED
BY VARIATIONS IN
INPUT TIMING