Adaptive bit allocation for multi-channel audio encoding

Abstract

The invention provides a highly efficient technique for encoding a multi-channel audio signal. The invention relies on the basic principle of encoding a first signal representation of one or more of the multiple channels in a first encoder (130) and encoding a second signal representation of one or more of the multiple channels in a second, multi-stage, encoder (140). This procedure is significantly enhanced by providing a controller (150) for adaptively allocating a number of encoding bits among the different encoding stages of the second, multi-stage, encoder (140) in dependence on multi-channel audio signal characteristics.

Description

technical field [0001] In general, the present invention relates to audio encoding and decoding techniques, and more particularly, to multi-channel audio encoding, such as stereo encoding. Background technique [0002] There is a great market need for transmitting and storing audio signals at low bit rates while maintaining high audio quality. In particular, low bit rate operation is a major cost factor where transmission resources or storage are limited. This is often the case, for example, in streaming and messaging applications of mobile communication systems such as GSM, UMTS or CDMA. [0003] A general example of an audio transmission system employing multi-channel encoding and decoding is schematically illustrated in FIG. 1 . The whole system mainly includes a multi-channel audio encoder 100 and a sending module 10 on the sending side, and a receiving module 20 and a multi-channel audio decoder 200 on the receiving side. [0004] The simplest way of stereo or multi-...

AI Technical Summary

Problems solved by technology

However, this technique requires the different source signals to be separated, and is therefore generally not applicable to stereo or multi-channel encoding

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