Techniques for ATV transmission developed by the DSRC, with support initially from NBC and RCA/GE Consumer Electronics (now Thomson Consumer Electronics) and with later support from such organizations as ABC and HBO. There are two ACTVs. a) ACTV I is a channel-compatible, receiver-compatible system using many different techniques to add widescreen panels and increase horizontal and vertical resolution. Among the techniques are the filling of a Fukinuki hole, time compression, seam-elimination, spatio-temporal filtering, and quadrature modulation of the picture carrier. The last prevents direct compatibility with videotape recorders and with ordinary satellite transmission techniques. b) ACTV II is ACTV I plus an augmentation channel to improve resolution and sound.