Stereo Compatible Multi-Channel Audio Coding

Encoder for deriving a parametric representation of a multi-channel audio signal, the parametric representation having parameters suited to be used together with a monophonic downmixed signal, the encoder comprising:

• a spatial parameter calculator for calculating a one or more spatial parameters describing spatial properties of the multi-channel signal;
• a stereo parameter calculator for calculating a stereo parameter describing spatial properties of a stereo downmix signal derived from the multi-channel signal;
• and
• a parameter combiner for generating the parametric representation by combining the one or more spatial parameters and the stereo parameters using a combination rule, wherein the parameter combiner is operative to use a combination rule resulting in a decoder usable stereo parameter and an information on the one or more spatial parameters, which represents, together with the decoder usable stereo parameter, the one or more spatial parameters.

Method for deriving a parametric representation of a multi-channel audio signal, the parametric representation having parameters suited to be used together with a monophonic downmix signal, the method comprising:

• calculating a one or more spatial parameters describing spatial properties of the multi-channel signal;
• calculating a stereo parameter describing spatial properties of a stereo downmix signal derived from the multi-channel signal;
• and
• generating the parametric representation by combining the one or more spatial parameters and the stereo parameter using a combination rule, wherein using the combination rule results in a decoder usable stereo parameter and in information on the one or more spatial parameters, which represents, together with the decoder usable stereo parameter, the one or more spatial parameters.

Transmitter or audio recorder having an encoder for deriving a parametric representation of a multi-channel audio signal, the parametric representation having parameters suited to be used together with a monophonic downmixed signal, the encoder comprising:

• a spatial parameter calculator for calculating a one or more spatial parameters describing spatial properties of the multi-channel signal;
• a stereo parameter calculator for calculating a stereo parameter describing spatial properties of a stereo downmix signal derived from the multi-channel signal;
• and
• a parameter combiner for generating the parametric representation by combining the one or more spatial parameters and the stereo parameters using a combination rule, wherein the parameter combiner is operative to use a combination rule resulting in a decoder usable stereo parameter and an information on the one or more spatial parameters, which represents, together with the decoder usable stereo parameter, the one or more spatial parameters.

Method of transmitting or audio recording, the method having a method for deriving a parametric representation of a multi-channel audio signal, the parametric representation having parameters suited to be used together with a monophonic downmix signal, the method comprising:

• calculating a one or more spatial parameters describing spatial properties of the multi-channel signal;
• calculating a stereo parameter describing spatial properties of a stereo downmix signal derived from the multi-channel signal;
• and
• generating the parametric representation by combining the one or more spatial parameters and the stereo parameter using a combination rule, wherein using the combination rule results in a decoder usable stereo parameter and in information on the one or more spatial parameters, which represents, together with the decoder usable stereo parameter, the one or more spatial parameters.

Transmission system having a transmitter and a receiver;

• the transmitter having an encoder for deriving a parametric representation of a multi-channel audio signal, the parametric representation having parameters suited to be used together with a monophonic downmixed signal, the encoder comprising:
• a spatial parameter calculator for calculating a one or more spatial parameters describing spatial properties of the multi-channel signal;
• a stereo parameter calculator for calculating a stereo parameter describing spatial properties of a stereo downmix signal derived from the multi-channel signal;
• and
• a parameter combiner for generating the parametric representation by combining the one or more spatial parameters and the stereo parameters using a combination rule, wherein the parameter combiner is operative to use a combination rule resulting in a decoder usable stereo parameter and an information on the one or more spatial parameters, which represents, together with the decoder usable stereo parameter, the one or more spatial parameters;
• and
• the receiver having a multi-channel audio decoder for processing a parametric representation, wherein the parametric representation is comprising information on one or more spatial parameters describing spatial properties of a multi-channel signal and a stereo parameter describing spatial properties of a stereo downmix of the multi-channel signal, wherein the information on the one or more spatial parameters and the stereo parameter, when combined using a combination rule, results in one or more spatial parameters, the decoder comprising:
• a parameter reconstructor for combining the stereo parameter and the information on the one or more spatial parameters using the combination rule to obtain the one or more spatial parameters.

Method of transmitting and receiving, the method including a transmitting method having a method for deriving a parametric representation of a multi-channel audio signal, the parametric representation having parameters suited to be used together with a monophonic downmix signal, the method comprising:

• calculating a one or more spatial parameters describing spatial properties of the multi-channel signal;
• calculating a stereo parameter describing spatial properties of a stereo downmix signal derived from the multi-channel signal;
• and
• generating the parametric representation by combining the one or more spatial parameters and the stereo parameter using a combination rule, wherein using the combination rule results in a decoder usable stereo parameter and in information on the one or more spatial parameters, which represents, together with the decoder usable stereo parameter, the one or more spatial parameters;
• and
• a receiving method, having a method for processing a parametric representation, wherein the parametric representation is comprising information on a one or more spatial parameters describing spatial properties of a multi-channel signal and a stereo parameter describing spatial properties of a stereo-downmix of the multi-channel signal, wherein the information on the one or more spatial parameters and the stereo parameters, when combined using a combination rule, results in the one or more spatial parameters, the method comprising:
• combining the stereo parameter and the information on the one or more spatial parameters using the combination rule to obtain the one or more spatial parameters.

Computer program for performing, when running on a computer, a method for deriving a parametric representation of a multi-channel audio signal, the parametric representation having parameters suited to be used together with a monophonic downmix signal, the method comprising:

• calculating a one or more spatial parameters describing spatial properties of the multi-channel signal;
• calculating a stereo parameter describing spatial properties of a stereo downmix signal derived from the multi-channel signal;
• and
• generating the parametric representation by combining the one or more spatial parameters and the stereo parameter using a combination rule, wherein using the combination rule results in a decoder usable stereo parameter and in information on the one or more spatial parameters, which represents, together with the decoder usable stereo parameter, the one or more spatial parameters.