AUXILIARY VIDEO DATA SLICER

摘要

An auxiliary video data slicer for extracting auxiliary video information in a v ideo signal includes a peak detector (220, 230) for determining the peak amplitude of horizontal sync pulses and of a run-i n-clock (RIC) waveform included in the auxiliary video information. A variable threshold voltage (PEAK VREF) for the peak detecto r is varied in a first range to detect the sync pulse peak. A threshold voltage (SYNC VREF) for detecting the leading edge of sync pulses is derived from the peak amplitude of the sync pulses. The location of the RIC waveform interval within a particula r line of video is determined based on the detection of a sync pulse edge (SYNC). The variable threshold voltage is varied in a second range to detect the peak amplitude of the RIC signal. A data slicing threshold level (DATA VREF) for extracting auxili ary video information is derived from the peak value of the RIC signal. The auxiliary video data slicer may be implemented in a n integrated circuit.