Multi-channel hierarchical audio coding with compact side information

Decoder for processing a parametric representation of an original audio signal, the original audio signal having at least two original left channels on a left side and at least two original right channels on a right side with respect to a listening position, comprising:

• a receiver for providing the parametric representation of the audio signal, the receiver being operative to provide level information for channel pairs and to provide a left/right coherence measure for a channel pair including a left channel and a right channel, the left/right coherence measure representing a coherence information between at least one channel pair including a first channel only having information from the left side and a second channel only having information from the right side;
• and
• a processor for supplying parametric information for channel pairs, the processor being operative to select level information from the parametric representation and to derive coherence information for at least one channel pair using the left/right coherence measure, the at least one channel pair including a first channel only having information from the left side and a second channel only having information from the right side.

A method for generating a parametric representation of an audio signal having at least two original left channels and at least two original right channels with respect to a listening position, the method comprising:

• generating parametric information by separately processing several pairs of channels to derive a level information for processed channel pairs and by deriving coherence information for a channel pair including a first channel only having information from the left side and a second channel only having information from the right side, and
• providing the parametric representation by selecting level information for travel pairs and by determining a left/right coherence measure using the coherence information and introducing the left/right coherence measure into an output datastream.

A method for processing a parametric representation of an original audio signal, the original audio signal having at least two original left channels on the left side and at least two original right channels on the right side with respect to a listening position-, the method comprising:

• providing the parametric representation of the audio signal by providing a level information for channel pairs and by providing a left/right coherence measure for a channel pair including a left channel and a right channel, the left/right coherence measure representing a coherence information between at least one channel pair including a first channel only having information from the left side and a second channel only having information from the right side;
• and
• supplying parametric information for channel pairs by selecting level information from the parametric representation and by deriving coherence information for at least one channel pair using the left/right coherence measure, the at least one channel pair including a first channel only having information from the left side and a second channel only having information from the right side.

Encoded audio data with side information, the side information comprising a parametric representation of an audio signal having at least two original left channels on a left side and two original right channels on a right side with respect to a listening position, wherein the parametric representation comprises level differences for channel pairs and a left/right coherence measure derived from coherence information from a channel pair including a first channel only having information from the left side and a second channel only having information from the right side, the parametric representation not including a coherence measure between original channels on the same side with respect to the listening position.

Computer readable storage medium, having stored thereon encoded audio data with side information, the side information comprising a parametric representation of an audio signal having at least two original left channels on a left side and two original right channels on a right side with respect to a listening position, wherein the parametric representation comprises level differences for channel pairs and a left/right coherence measure derived from coherence information from a channel pair including a first channel only having information from the left side and a second channel only having information from the right side, the parametric representation not including a coherence measure between original channels on the same side with respect to the listening position.

Receiver or audio player having a decoder for processing a parametric representation of an original audio signal, the original audio signal having at least two original left channels on a left side and at least two original right channels on a right side with respect to a listening position, comprising:

• a receiver for providing the parametric representation of the audio signal, the receiver being operative to provide level information for channel pairs and to provide a left/right coherence measure for a channel pair including a left channel and a right channel, the left/right coherence measure representing a coherence information between at least one channel pair including a first channel only having information from the left side and a second channel only having information from the right side;
• and
• a processor for supplying parametric information for channel pairs, the processor being operative to select level information from the parametric representation and to derive coherence information for at least one channel pair using the left/right coherence measure, the at least one channel pair including a first channel only having information from the left side and a second channel only having information from the right side.

Transmitter or audio recorder having an encoder for generating a parametric representation of an audio signal having at least two original left channels on a left side and two original right channels on a right side with respect to a listening position, comprising:

• a generator for generating parametric information, the generator being operative to separately process several pairs of channels to derive a level information for processed channel pairs, and to derive coherence information for a channel pair including a first channel only having information from the left side and a second channel only having information from the right side;
• and
• a provider for providing the parametric representation by selecting the level information for channel pairs and by determining a left/right coherence measure using the coherence information and to introduce the left/right coherence measure into an output datastream.

Method of receiving or audio playing, the method having a method for processing a parametric representation of an original audio signal, the original audio signal having at least two original left channels on the left side and at least two original right channels on the right side with respect to a listening position, the method comprising:

• providing the parametric representation of the audio signal by providing a level information for channel pairs and by providing a left/right coherence measure for a channel pair including a left channel and a right channel, the left/right coherence measure representing a coherence information between at least one channel pair including a first channel only having information from the left side and a second channel only having information from the right side;
• and
• supplying parametric information for channel pairs by selecting level information from the parametric representation and by deriving coherence information for at least one channel pair using the left/right coherence measure, the at least one channel pair including a first channel only having information from the left side and a second channel only having information from the right side.

Method of transmitting or audio recording, the method having a method a method for generating a parametric representation of an audio signal having at least two original left channels and at least two original right channels with respect to a listening position, the method comprising:

• generating parametric information by separately processing several pairs of channels to derive a level information for processed channel pairs and by deriving coherence information for a channel pair including a first channel only having information from the left side and a second channel only having information from the right side;
• and
• providing the parametric representation by selecting level information for travel pairs and by determining a left/right coherence measure using the coherence information and introducing the left/right coherence measure into an output datastream.