A system in which drooping of the video levels due to leakage currents and
proper DC bias level is addressed by providing a charge into the video
signal to offset the leakage currents and to provide DC bias. To
determine the leakage current level, measurements are made measuring the
voltages of the syncs and the blanking intervals. To determine the DC
bias, a measurement is made of the sync. Over a series of video lines
these measurements are averaged. If the average is below the desired
level, a charge is provided via a current source to the incoming signal.
By having the current source provide charge during each video line, droop
is reduced and the proper DC bias is provided.