blanking pulse การใช้

• Most consumer VCRs use the known black level of the vertical blanking pulse to set their recording levels.
• Most VCR circuits use the amplitude of the vertical blanking pulse to operate the AGC . Video copy control schemes such as Macrovision exploit this, inserting spikes in the pulse which will be ignored by most television sets, but cause a VCR's AGC to overcorrect and corrupt the recording.