Abstract: A method of wiping from one television video source to another encompasses the steps of mixing the color burst information during each horizontal blanking interval while wiping the video information carrying portion of each horizontal scan interval from one source to another. A special effects circuit for accomplishing this method includes a pair of variable gain linear amplifiers each having an input terminal coupled to a respective source of video signals to be wiped, and a circuit for providing a wipe control signal applied to the input of the amplifiers to control the gain of the amplifiers during the horizontal blanking interval in proportion to the percentage of wiping taking place, and control the variable gain amplifiers during the remaining portion of each horizontal scanning interval to apply either video from one or the other video sources.

Abstract: A video recording system for use in recording video information with a helical scan recorder coupled to a portable camera includes a delayed vertical sync generator receiving video information including normal vertical and horizontal synchronization signals from the camera. The delayed sync generator delays vertical synchronization signals with respect to the start of each vertical banking interval such that the head switching point of the helical scanning tape recording apparatus occurs during the vertical blanking interval before the delayed synchronization signals. This eliminates line distortion which otherwise occurs during the video signal information of each scanning frame of the video signal and places it in the vertical blanking interval where it is not displayed as a line distortion in the reproduced video signal on a television screen.