Adaptive residual audio coding

Method for encoding an audio signal having at least two channels, the method comprising:

• deriving a spatial parameter from the audio signal, wherein the spatial parameter describes an interrelation between the at least two channels;
• limiting the spatial parameter using a limiting rule to derive a limited spatial parameter, wherein the limiting rule depends on an interrelation between the at least two channels;
• and
• deriving a downmix signal and a residual signal from the audio signal using a down-mixing rule depending on the limited spatial parameter.

Transmitter or audio recorder having a audio encoder for encoding an audio signal having at least two channels, comprising:

• a parameter extractor for deriving a spatial parameter from the audio signal, wherein the spatial parameter describes an interrelation between the at least two channels;
• a limiter for limiting the spatial parameter using a limiting rule to derive a limited spatial parameter, wherein the limiting rule depends on an interrelation between the at least two channels;
• and
• a down-mixer for deriving a downmix signal and a residual signal from the audio signal using a down-mixing rule depending on the limited spatial parameter.

Method of transmitting or audio recording the method having a method of generating an encoded signal, the method comprising a method for encoding an audio signal having at least two channels, the method comprising:

• deriving a spatial parameter from the audio signal, wherein the spatial parameter describes an interrelation between the at least two channels;
• limiting the spatial parameter using a limiting rule to derive a limited spatial parameter, wherein the limiting rule depends on an interrelation between the at least two channels;
• and
• deriving a downmix signal and a residual signal from the audio signal using a down-mixing rule depending on the limited spatial parameter.

Transmission system having a transmitter and a receiver,

• the transmitter having an audio encoder for encoding an audio signal having at least two channels, comprising:
• a parameter extractor for deriving a spatial parameter from the audio signal, wherein the spatial parameter describes an interrelation between the at least two channels;
• a limiter for limiting the spatial parameter using a limiting rule to derive a limited spatial parameter, wherein the limiting rule depends on an interrelation between the at least two channels;
• and
• a down-mixer for deriving a downmix signal and a residual signal from the audio signal using a down-mixing rule depending on the limited spatial parameter;
• and
• the receiver having an audio decoder for decoding an encoded audio signal representing an original audio signal having at least two channels, the encoded audio signal having a downmix signal, a residual signal and a spatial parameter describing an interrelation between the at least two channels, comprising:
• a limiter for limiting the spatial parameter to derive a limited spatial parameter using a limiting rule, wherein the limiting rule depends on an interrelation between the at least two channels;
• and
• an up-mixer for deriving a reconstruction of the original audio signal from the downmix signal and the residual signal using an up-mixing rule depending on the limited spatial parameter.

Method of transmitting and receiving, the method including

• a transmitting method having a method of generating an encoded signal of an audio signal having at least two channels, the method comprising:
• deriving a spatial parameter from the audio signal, wherein the spatial parameter describes an interrelation between the at least two channels;
• limiting the spatial parameter using a limiting rule to derive a limited spatial parameter, wherein the limiting rule depends on an interrelation between the at least two channels;
• and
• deriving a downmix signal and a residual signal from the audio signal using a down-mixing rule depending on the limited spatial parameter;
• and
• a receiving method, having a method for decoding an encoded audio signal, the method comprising:
• limiting the spatial parameter to derive a limited spatial parameter using a limiting rule, wherein the limiting rule depends on an interrelation between the at least two channels;
• and
• deriving a reconstruction of the original audio signal from the downmix signal and the residual signal using an up-mixing rule depending on the limited spatial parameter.