Analog Television - Digital Video and Audio Broadcasting Technology - page 24

The transmission parameters of the data line are:

• Line: 16/329

• Code: Return-to-zero code

• Data rate: 2.5 Mbit/s

• Level: 500 mV

• Data: 15 bytes per line

According to DVB, these signals from the vertical blanking interval are
partially regenerated in the receiver to retain compatibility with analog
television. The test line signals, however, are no longer provided.

2.7 Measurements on Analog Video Signals

Analog video signals have been measured since the beginning of the TV
age, initially with simple oscilloscopes and vectorscopes and later with e-
ver more elaborate video analyzers, the latest models of which were digital
(Fig. 2.22.). These video measurements are intended to identify the distor-
tions in the analog video signal. The following test parameters are deter-
mined with the aid of test lines:

• White bar amplitude

• Sync amplitude

• Burst amplitude

• Tilt on the white bar

• 2T pulse amplitude

• 2T K factor

• Luminance-chrominance amplitude on the 20T pulse

• Luminance-chrominance delay on the 20T pulse

• Static nonlinearity on the grayscale

• Differential gain on the grayscale with color subcarrier

• Differential phase on the grayscale with color subcarrier

• Weighted and unweighted luminance signal/noise ratio

• Hum

In addition, an analog TV test receiver also provides information on:

• Vision carrier level