Apparatus and method for codebook level estimation of coded audio frames in a bit stream domain to determine a codebook from a plurality of codebooks

An apparatus for generating an output data stream from input data, comprising:

• a receiver interface for receiving the input data comprising an encoded audio signal,
• an apparatus for level estimation of the encoded audio signal comprising:
• a codebook determinator for determining a codebook from a plurality of codebooks as an identified codebook, wherein the audio signal has been encoded by employing the identified codebook, wherein the identified codebook comprises a plurality of codewords, and
• an estimation unit, wherein the estimation unit is configured to derive a codebook level value associated with the identified codebook as a derived level value, wherein the codebook level value indicates a sum of averaged probability-weighted level sum values of all codewords of the identified codebook, wherein each of the averaged probability-weighted level sum values of the codewords of the identified codebook depends on how often a sequence of number values of a codeword of the identified codebook appears compared to other sequences of number values of other codewords of the identified codebook, wherein the estimation unit is configured to estimate a level estimate of the audio signal using the derived level value, and
• a decider for deciding, whether a portion of the encoded audio signal is to be introduced into the output data stream or not, based on the level estimation for the portion of the output data stream.

A method for generating a codebook level value for a codebook, comprising:

• determining a sequence of number values associated with a codeword of the codebook for each codeword of the codebook,
• determining an inverse-quantized sequence of number values for each codeword of the codebook by applying an inverse quantizer to the number values of the sequence of number values of a codeword for each codeword of the codebook,
• determining a sequence of level values for each codeword of the codebook by determining a square of each value of the inverse-quantized sequence of number values of a codeword for each codeword of the codebook when an energy value is to be generated as codebook level value, or by determining a sequence of level values for each codeword of the codebook by determining an absolute value of each value of the inverse-quantized sequence of number values of a codeword for each codeword of the codebook when an amplitude value is to be generated as codebook level value, or by transforming each value of the inverse-quantized sequence of number values of a codeword to a loudness domain for each codeword of the codebook when a loudness value is to be determined as codebook level value,
• calculating a level sum value for each codeword of the codebook by summing values of the sequence of level values for each codeword of the codebook,
• determining a probability-weighted level sum value for each codeword of the codebook by multiplying the level sum value of a codeword by a probability value associated with the codeword for each codeword of the codebook,
• determining an averaged probability-weighted level sum value for each codeword of the codebook by dividing the probability-weighted level sum value of a codeword by a dimension value associated with the codebook for each codeword of the codebook, and
• calculating the codebook level value by summing the averaged probability-weighted level sum values of all codewords.

An apparatus for buffer management comprising:

• a buffer access unit for accessing buffer audio data of a buffer as accessed buffer audio data, wherein the buffer audio data comprises an encoded audio signal,
• an apparatus for level estimation of the encoded audio signal comprising:
• a codebook determinator for determining a codebook from a plurality of codebooks as an identified codebook, wherein the audio signal has been encoded by employing the identified codebook, and
• an estimation unit, wherein the estimation unit is configured to derive a codebook level value associated with the identified codebook as a derived level value, wherein the codebook level value indicates a sum of averaged probability-weighted level sum values of all codewords of the identified codebook, wherein each of the averaged probability-weighted level sum values of the codewords of the identified codebook depends on how often a sequence of number values of a codeword of the identified codebook appears compared to other sequences of number values of other codewords of the identified codebook, and
• a decider for deciding, whether the accessed buffer audio data is to be deleted from the buffer or not, based on the level estimation of the encoded audio signal, wherein
• the estimation unit estimates the level estimation of the encoded audio signal depending on the derived level value which depends on a sequence of level values for each codeword of the identified codebook, and
• each level value of the sequence of level values indicates a value of the each codeword of the identified codebook.

A method for level estimation of an encoded audio signal, comprising:

• determining a codebook from a plurality of codebooks as an identified codebook,
• wherein the audio signal has been encoded by employing the identified codebook,
• deriving a codebook level value associated with the identified codebook as a derived level value, wherein the codebook level value indicates a sum of averaged probability-weighted level sum values of all codewords of the identified codebook, wherein each of the averaged probability-weighted level sum values of the codewords of the identified codebook depends on how often a sequence of number values of a codeword of the identified codebook appears compared to other sequences of number values of other codewords of the identified codebook, and
• estimating a level estimate of the audio signal using the derived level value.

A method for generating an output data stream from input data, comprising:

• receiving the input data comprising an encoded audio signal,
• determining a codebook from a plurality of codebooks as an identified codebook, wherein the audio signal has been encoded by employing the identified codebook,
• deriving a codebook level value associated with the identified codebook as a derived level value, wherein the codebook level value indicates a sum of averaged probability-weighted level sum values of all codewords of the identified codebook, wherein each of the averaged probability-weighted level sum values of the codewords of the identified codebook depends on how often a sequence of number values of a codeword of the identified codebook appears compared to other sequences of number values of other codewords of the identified codebook,
• estimating a level estimate of the audio signal using the derived level value, and
• deciding, whether a portion of the encoded audio signal is to be introduced into the output data stream or not, based on the level estimate for the portion of the output data stream.

A method for storing input data comprising an encoded audio signal in a buffer, comprising:

• receiving the input data comprising the encoded audio signal,
• determining a codebook from a plurality of codebooks as an identified codebook, wherein the audio signal has been encoded by employing the identified codebook,
• deriving a codebook level value associated with the identified codebook as a derived level value, wherein the codebook level value indicates a sum of averaged probability-weighted level sum values of all codewords of the identified codebook, wherein each of the averaged probability-weighted level sum values of the codewords of the identified codebook depends on how often a sequence of number values of a codeword of the identified codebook appears compared to other sequences of number values of other codewords of the identified codebook,
• estimating a level estimate of the audio signal using the derived level value, and
• deciding, whether a portion of the encoded audio signal is to be stored in the buffer or not, based on the level estimate for the portion of the output data stream, wherein
• the estimating of the level estimate of the audio signal depends on the derived level value which depends on a sequence of level values for each codeword of the identified codebook, and
• each level value of the sequence of level values indicates a value of the each codeword of the identified codebook.

A non-transitory computer readable medium including a computer program implementing, when being executed by a computer or a signal processor, a method for generating a codebook level value for a codebook comprising:

• determining a sequence of number values associated with a codeword of the codebook for each codeword of the codebook, determining an inverse-quantized sequence of number values for each codeword of the codebook by applying an inverse quantizer to the number values of the sequence of number values of a codeword for each codeword of the codebook, determining a sequence of level values for each codeword of the codebook by determining a square of each value of the inverse-quantized sequence of number values of a codeword for each codeword of the codebook when an energy value is to be generated as codebook level value, or by determining a sequence of level values for each codeword of the codebook by determining an absolute value of each value of the inverse-quantized sequence of number values of a codeword for each codeword of the codebook when an amplitude value is to be generated as codebook level value, or by transforming each value of the inverse-quantized sequence of number values of a codeword to a loudness domain for each codeword of the codebook when a loudness value is to be determined as codebook level value, calculating a level sum value for each codeword of the codebook by summing the values of the sequence of level values for each codeword of the codebook, determining a probability-weighted level sum value for each codeword of the codebook by multiplying the level sum value of a codeword by a probability value associated with the codeword for each codeword of the codebook, determining an averaged probability-weighted level sum value for each codeword of the codebook by dividing the probability-weighted level sum value of a codeword by a dimension value associated with the codebook for each codeword of the codebook, and calculating the codebook level value by summing the averaged probability-weighted level sum values of all codewords, wherein
• a level estimate of the audio signal is estimated depending on the derived level value which depends on a sequence of level values for each codeword of the identified codebook, and
• each level value of the sequence of level values indicates a value of the each codeword of the identified codebook.

A non-transitory computer readable medium including a computer program implementing, when being executed by a computer or a signal processor, a method for generating an output data stream from input data comprising:

• receiving the input data comprising an encoded audio signal, determining a codebook from a plurality of codebooks as an identified codebook, wherein the audio signal has been encoded by employing the identified codebook,
• deriving a codebook level value associated with the identified codebook as a derived level value, wherein the codebook level value indicates a sum of averaged probability-weighted level sum values of all codewords of the identified codebook, wherein each of the averaged probability-weighted level sum values of the codewords of the identified codebook depends on how often a sequence of number values of a codeword of the identified codebook appears compared to other sequences of number values of other codewords of the identified codebook,
• estimating a level estimate of the audio signal using the level value, and
• deciding, whether a portion of the encoded audio signal is to be introduced into the output data stream or not, based on the level estimate for the portion of the output data stream, wherein
• the estimating of the level estimate of the audio signal depends on the derived level value which depends on a sequence of level values for each codeword of the identified codebook, and
• each level value of the sequence of level values indicates a value of the each codeword of the identified codebook.

A non-transitory computer readable medium including a computer program implementing, when being executed by a computer or a signal processor, a method for storing input data comprising an encoded audio signal in a buffer comprising:

• receiving the input data comprising the encoded audio signal, determining a codebook from a plurality of codebooks as an identified codebook, wherein the audio signal has been encoded by employing the identified codebook,
• deriving a codebook level value associated with the identified codebook as a derived level value, wherein the codebook level value indicates a sum of averaged probability-weighted level sum values of all codewords of the identified codebook, wherein each of the averaged probability-weighted level sum values of the codewords of the identified codebook depends on how often a sequence of number values of a codeword of the identified codebook appears compared to other sequences of number values of other codewords of the identified codebook,
• estimating a level estimate of the audio signal using the level value, and
• deciding, whether a portion of the encoded audio signal is to be stored in the buffer or not, based on the level estimate for the portion of the output data stream, wherein
• the estimating of the level estimate of the audio signal depends on the derived level value which depends on a sequence of level values for each codeword of the identified codebook, and
• each level value of the sequence of level values indicates a value of the each codeword of the identified codebook.