dolby prologic decoder

摘要

The nucleus block of a Dolby Prologic decoder comprises two main sections: an adaptation section (21) and a matrix section (22) comprising voltage controlled amplifiers VCA. The adaptive section examines the two channel input signal to find in which direction the dominance of the sound field is located, and then generates control signals controlling the amplifiers of the matrix section. In this way we obtain the four channel output signal (R, L, C and S). According to the invention the two channel audio signal (Lt, Rt) is supplied to a block performing linear signal processing operations and processing separately the signal of both channels. The two channel output signal of the DSP block is the input signal of the matrix section (22). In this way it is possible to affect all four output channels by processing only two channels, without otherwise interfering with the function of the decoder. IMAGE