NUC970 Technical Reference Manual
Publication Release Date: Dec. 15, 2015
- 1059 -
Revision V1.30
NUC97
0
T
E
CHNIC
A
L
RE
F
E
RE
N
CE
MA
NUA
L
JPEG Encode Primary Quantization-Table Control Register (JPRIQC)
Register
Offset
R/W
Description
Reset Value
JPRIQC
J 0x010 R/W
JPEG Encode Primary Q-Table Control Register
0x0000_00F4
31
30
29
28
27
26
25
24
Reserved
23
22
21
20
19
18
17
16
Reserved
15
14
13
12
11
10
9
8
Reserved
7
6
5
4
3
2
1
0
P_QADJUST
P_QVS
Bits
Description
[31:8]
Reserved
Reserved.
[7:4]
P_QADJUST
Primary Quantization-table Adjustment
If the sum of the position (x, y) of quantization-table is greater than
P_QADJUST
, the
quantization value will be set to 127. Otherwise the value will keep as the original.
8x8 DCT block: x = 0~7, y = 0~7.
if ((x+y) > P_QADJUST) => Q
’ = 127.
else => Q’ = Q.
[3:0]
P_QVS
Primary Quantization-table Scaling Control
Q’ = (P_QVS[3]*2*Q)+(P_QVS[2]*Q)+(P_QVS[1]*Q/2)+(P_QVS[0]*Q/4).