Audio Decoder, Audio Encoder, Method for Decoding an Audio Signal, Method for Encoding an Audio Signal, Computer Program and Audio Signal

A method for providing a decoded audio information on the basis of an encoded audio information, the method comprising:

• decoding the entropy-encoded audio information taking into account a context, which is based on a previously-decoded audio information in a non-reset state of operation,
• wherein decoding the entropy-encoded audio information comprises selecting a mapping information for deriving the decoded audio information from the encoded audio information, in dependence on the context, and using the selected mapping information for deriving a first portion of the decoded audio information;
• and
• wherein decoding the entropy-encoded audio information also comprises resetting the context for selecting the mapping information to a default context, which is independent from the previously-decoded audio information, in response to a side information, and using the mapping information, which is based on the default context, for decoding a second portion of the decoded audio information.

An audio encoder for providing an encoded audio information on the basis of an input audio information, the audio encoder comprising:

• a context-based entropy encoder configured to encode a given audio information of the input audio information in dependence on a context, which context is based on an adjacent audio information, temporally or spectrally adjacent to the given audio information, in a non-reset state of operation;
• wherein the context-based entropy encoder is configured to select a mapping information for deriving the encoded audio information from the input audio information, in dependence on the context;
• and
• wherein the context-based entropy encoder comprises a context resetter configured to reset the context for selecting the mapping information to a default context within a contiguous piece of input audio information, in response to the occurrence of a context reset condition;
• and
• wherein the audio encoder is configured to provide a side information of the encoded audio information indicating the presence of a context reset condition.

A method for providing an encoded audio information on the basis of an input audio information, the method comprising:

• encoding a given audio information of the input audio information in dependence on a context, which context is based on an adjacent audio information, temporally or spectrally adjacent to the given audio information, in a non-reset state of operation,
• wherein encoding the given audio information in dependence on the context comprises selecting a mapping information, for deriving the encoded audio information from the input audio information, in dependence on the context, resetting the context for selecting the mapping information to a default context within a contiguous piece of input audio information in response to the occurrence of a context reset condition;
• and
• providing a side information of the encoded audio information indicating the presence of the context reset condition.

A computer program for performing the method for providing a decoded audio information on the basis of an encoded audio information, the method comprising:

• decoding the entropy-encoded audio information taking into account a context, which is based on a previously-decoded audio information in a non-reset state of operation,
• wherein decoding the entropy-encoded audio information comprises selecting a mapping information for deriving the decoded audio information from the encoded audio information, in dependence on the context, and using the selected mapping information for deriving a first portion of the decoded audio information;
• and
• wherein decoding the entropy-encoded audio information also comprises resetting the context for selecting the mapping information to a default context, which is independent from the previously-decoded audio information, in response to a side information, and using the mapping information, which is based on the default context, for decoding a second portion of the decoded audio information,
• when the computer program runs on a computer.

A computer program for performing the method for providing an encoded audio information on the basis of an input audio information, the method comprising:

• encoding a given audio information of the input audio information in dependence on a context, which context is based on an adjacent audio information, temporally or spectrally adjacent to the given audio information, in a non-reset state of operation,
• wherein encoding the given audio information in dependence on the context comprises selecting a mapping information, for deriving the encoded audio information from the input audio information, in dependence on the context,
• resetting the context for selecting the mapping information to a default context within a contiguous piece of input audio information in response to the occurrence of a context reset condition;
• and
• providing a side information of the encoded audio information indicating the presence of the context reset condition,
• when the computer program runs on a computer.

An encoded audio signal, the encoded audio signal comprising:

• an encoded representation of a plurality of sets of spectral values, wherein a plurality of the sets of spectral values are encoded in dependence on an non-reset context, which is dependent on a respective preceding set of spectral values;
• wherein a plurality of the sets of spectral values are encoded in dependence on a default context, which is independent from a respective preceding set of spectral values;
• and
• wherein the encoded audio signal comprises a side information signaling if a set of spectral coefficients is encoded in dependence on a non-reset context or in dependence on the default context.