The overall format of one complete line of the digital video data stream includes the following sections. The horizontal scan is considered to start with the beginning of the EAV section.
• EAV - End of Active Video (timing reference signal) 2 samples (4 words)
• Horizontal blanking 134 samples (268 words)
• SAV - Start of Active Video (timing reference signal) 2 samples (4 words)
• Active video 720 samples (1440 words)
EAV Timing Reference Signal:
The EAV Timing Reference consists of four words in the following format:
where:
F= Field select (defines which vertical scan during interlace scanning)
V= Vertical blanking
H= 1 indicating EAV
E3 = V xor H
E2 = F xor H
E1 = F xor V
E0 = F xor V xor H
Horizontal Blanking:
The horizontal blanking section consists of a repeating pattern: 1000 0000 0001 0000 ........
SAV Timing Reference Signal:
The SAV Timing Reference consists of four words in the following format:
where:
F= Field select (defines which vertical scan during interlace scanning)
V= Vertical blanking
H= 0 indicating SAV
E3 = V xor H
E2 = F xor H
E1 = F xor V
E0 = F xor V xor H
Active Video:
The active video section consists of the Y, Cb, Cr data in the following sequence. The Y, Cb and Cr values are the scaled, offset, digitized versions of Y, U and V.
• Cr
• Y
• Cb
• Y
Vertical Format
The details of the vertical format are shown in the complete screen diagrammed below. The scan is of the interlace type which means that the odd lines are scanned first, followed by the even lines. The symbols "F" and "V" refer to the values contained in bits P8 and P7 of the EAV and SAV timing reference words.
