BTSC ENCODER
The disclosed BTSC encoder includes a left high pass filter means for receiving a digital left channel audio signal and for digitally high pass filtering the digital left channel audio signal and thereby generating a digital left filtered signal; a right high pass filter means for receiving a digital right channel audio signal and for digitally high pass filtering the digital right channel audio signal and thereby generating a digital right filtered signal; a matrix means for receiving the digital left and digital right filtered signals, and including means for summing the digital left and digital right filtered signals and thereby generating a digital sum signal, and including means for subtracting one of the digital left and digital right filtered signals from the other of the digital left and digital right filtered signals and thereby generating a digital difference signal; a difference channel processing means for digitally processing the digital difference signal; and a sum channel processing means for digitally processing the digital sum signal.
1 . A method of providing inverse square root values for use in a digital adaptive signal weighting system responsive in accordance with the BTSC standard, comprising calculating and electronically storing said inverse square root values, and retrieving the inverse square root values and using the square root values to set the gain of a wideband gain control unit of the digital adaptive signal weighing system.