Hikmicro HM-TM36-LG/S - Page 41

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 Valid data includes odd field and even field. Each field has 288 lines. For each line, there are 1440 bytes,
of which 720 bytes are Y data, 360 bytes Cr data and 360 bytes Cb data. The value of Y data is from 16 to
235, the value of Cb or Cr data is from 16 to 240.
 Horizontal Blanking. It includes 280 bytes.
 Vertical Blanking
 Control Code
The format of valid line is shown in Figure 4-2. The EAV (End of Valid Video) and SAV (Start of Valid Video)
are embedded control codes. Both EAV and SAV codes have four bytes, of which the first three are the
fixed preamble: FF, 00, 00. The fourth byte, XY, is the control code. The 8 bit definition of XY is shown as
below:
 Bit7 (Const): Constant, always set to 1.
 Bit6 (F): Field bit, indicating the odd field or even field of the valid video.
 Bit5 (V): Vertical blanking status bit, indicating blanking or valid line.
 Bit4 (H): Horizontal blanking status bit, indicating SAV or EAV.
 Bit3-0 (P3P2P1P0): Protection bit. P3 = V(XOR)H; P2 = F(XOR)H; P1 = F(XOR)V; P0 = F(XOR)V(XOR)H.
Detailed description of EAV and SAV are shown in Table 4-1.
Table 4-1 Definition of EAV and SAV
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Hex
Description
1
0
0
0
0000
0x80
Even, Active, SAV
1
0
0
1
1101
0x9d
Even, Active, EAV
1
0
1
0
1011
0xab
Even, Blank, SAV
1
0
1
1
0110
0xb6
Even, Blank, EAV
1
1
0
0
0111
0xc7
Odd, Active, SAV
1
1
0
1
1010
0xda
Odd, Active, EAV
1
1
1
0
1100
0xec
Odd, Blank, SAV
1
1
1
1
0001
0xf1
Odd, Blank, EAV
Blanking in Figure 4-2 means the Horizontal Blanking, and it is 80H/10H in general.