A study of why cross channel prediction is not applicable to perceptual audio coding

We have studied and concluded that the time domain cross channel prediction is generally not applicable to perceptual audio coding. From the statistical analysis, correlation among certain channels seems to be enough to provide some coding gain and the prediction also successfully reduces the total energy of the signal to be coded. But this energy decrease and its resulting bit reduction mainly happens in the low frequency bands. In fact, the whitening effect of the prediction filter increases either the energy or the energy peaks in the high frequency region. As a result, more bits are required to code the high-frequency part of the signal and this increase outpaces the bit reduction realized in the low frequency region. Therefore, using cross channel linear prediction in the multichannel perceptual audio coding does not provide a net coding gain.