Audio or video encoder, audio or video decoder and related methods for processing multi-channel audio or video signals using a variable prediction direction

摘要

An encoder/decoder is based on a combination of two audio or video channels to obtain a first combination signal as a mid-signal and a residual signal derivable using a predicted side signal derived from the mid-signal. A decoder uses the prediction residual signal, the first combination signal, a prediction direction indicator and prediction information to derive decoded first channel and second channel signals. A real-to-imaginary transform can be applied for estimating the imaginary part of the spectrum of the first combination signal. The prediction signal used in the derivation of the prediction residual signal, the real-valued first combination signal is multiplied by a real portion of the complex prediction information and the estimated imaginary part of the first combination signal is multiplied by an imaginary portion of the complex prediction information.

主权项

1. An audio or video decoder for decoding an encoded multi-channel audio or video signal, the encoded multi-channel audio or video signal comprising an encoded first combination signal, an encoded prediction residual signal and prediction information, comprising:
a signal decoder for decoding the encoded first combination signal to acquire a decoded first combination signal, and for decoding the encoded residual signal to acquire a decoded residual signal; and a decoder calculator for calculating a decoded multi-channel signal comprising a decoded first channel signal, and a decoded second channel signal using the decoded residual signal, the prediction information, the decoded first combination signal and a prediction direction indicator indicating a prediction direction associated with the decoded prediction residual signal, so that the decoded first channel signal and the decoded second channel signal are at least approximations of a first channel signal and a second channel signal of a multi-channel signal, wherein the decoder calculator is configured for using a first calculation rule for calculating the decoded multi-channel signal in case of a first state of the prediction direction indicator and for using a second different calculation rule for calculating the decoded multi-channel signal in case of a second different state of the prediction direction indicator.