Non-uniform parameter quantization for advanced coupling

#The disclosure herein generally relates to audio coding. In particular, it relates to perceptually optimized quantization of parameters used in a system for parametric spatial coding of audio signals.

#The performance of low bit audio coding systems can be significantly improved for stereo signals when a parametric stereo (PS) coding tool is employed. In such a system, a mono signal is typically quantized and conveyed using a State-of-the-Art audio coder and stereo parameters are estimated and quantized in the encoder and added as side information to the bit stream. In the decoder, the stereo signal is reconstructed from the decoded mono signal with help of stereo parameters.

#There are several possible parametric stereo coding variants. Accordingly, there are several encoder types and, in addition to a mono downmix, they generate different stereo parameters that are embedded in the generated bit stream. Tools for such coding have also been standardized. An example of such a standard is MPEG-4 Audio (ISO/IEC 14496-3).

#In what follows, example embodiments will be described in greater detail and with reference to the accompanying drawings, in which:

#FIG. 1 discloses a block diagram of a parametric stereo encoding and decoding system in accordance with an example embodiment;

#FIG. 2 shows a block diagram relating to processing of stereo parameters in encoding part of the parametric stereo encoding system of FIG. 1;

#All the figures are schematic and generally only show parts which are necessary in order to elucidate the disclosure, whereas other parts may be omitted or merely suggested. Unless otherwise indicated, like reference numerals refer to like parts in different figures.

#In view of the above it is an object to provide encoders, decoders, systems comprising encoders and decoders, and associated methods which provide an increased efficiency and quality of the coded audio signal.

#According to a first aspect, example embodiments propose encoding methods, encoders, and computer products for encoding. The proposed methods, encoders and computer program products may generally have the same features and advantages.