PROCESS FOR REDUCING DATA IN THE TRANSMISSION AND/OR STORAGE OF DIGITAL SIGNALS FROM SEVERAL INTERDEPENDENT CHANNELS

摘要

The description relates to a process for reducing data in the transmission and/or storage of digital signals from several interdependent channels. As the signals from the channels are not mutually independent, it is possible further to reduce the quantity of data during transmission. In prior art processes for coding signals from two stereo channels, it is possible with a poor signal composition to cause interference through the coding which is not covered by the signal actually present in the channel and detract from listening enjoyment. In the process of the invention, by the use of the spectral values of corresponding blocks, the necessary data rate for separate coding of the two channels and for joint coding is balanced. The channels are jointly coded as long as the data rate for joint coding does not exceed the data rate for the separated coding of the channels concerned by a predeterminable value. In this case the spectral values of the corresponding blocks are similar so that joint coding is preferred. With very dissimilar signals, balancing results in separate signal transmission. The joint coding of several channels is temporarily suspended in order to be certain of preventing interference.