Apparatus and method for coding a time-discrete audio signal and apparatus and method for decoding coded audio data
First Claim
1. An apparatus for coding a time-discrete audio signal to obtain coded audio data, comprising:
- a quantizer for providing a quantization block of spectral values of the time-discrete audio signal quantized using a psychoacoustic model;
an inverse quantizer for inversely quantizing the quantization block and for rounding the inversely quantized spectral values to obtain a rounding block of rounded inversely quantized spectral values;
a generator for generating an integer block of integer spectral values using an integer transform algorithm formed to generate the integer block of spectral values from a block of integer time-discrete samples;
a combiner for forming a difference block depending on a spectral value-wise difference between the rounding block and the integer block, to obtain a difference block with difference spectral values; and
a processor for processing the quantization block and the difference block to generate coded audio data including information on the quantization block and information on the difference block.
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Abstract
A time-discrete audio signal is processed to provide a quantization block with quantized spectral values. Furthermore, an integer spectral representation is generated from the time-discrete audio signal using an integer transform algorithm. The quantization block having been generated using a psychoacoustic model is inversely quantized and rounded to then form a difference between the integer spectral values and the inversely quantized rounded spectral values. The quantization block alone provides a lossy psychoacoustically coded/decoded audio signal after the decoding, whereas the quantization block, together with the combination block, provides a lossless or almost lossless coded and again decoded audio signal in the decoding. By generating the differential signal in the frequency domain, a simpler coder/decoder structure results.
143 Citations
33 Claims
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1. An apparatus for coding a time-discrete audio signal to obtain coded audio data, comprising:
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a quantizer for providing a quantization block of spectral values of the time-discrete audio signal quantized using a psychoacoustic model;
an inverse quantizer for inversely quantizing the quantization block and for rounding the inversely quantized spectral values to obtain a rounding block of rounded inversely quantized spectral values;
a generator for generating an integer block of integer spectral values using an integer transform algorithm formed to generate the integer block of spectral values from a block of integer time-discrete samples;
a combiner for forming a difference block depending on a spectral value-wise difference between the rounding block and the integer block, to obtain a difference block with difference spectral values; and
a processor for processing the quantization block and the difference block to generate coded audio data including information on the quantization block and information on the difference block. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A method of coding a time-discrete audio signal to obtain coded audio data, comprising:
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providing a quantization block of spectral values of a time-discrete audio signal quantized using a psychoacoustic model;
inversely quantizing the quantization block and rounding the inversely quantized spectral values to obtain a rounding block of rounded inversely quantized spectral values;
generating an integer block of integer spectral values using an integer transform algorithm formed to generate the integer block of spectral values from a block of integer time-discrete samples;
forming a difference block depending on a spectral value-wise difference between the rounding block and the integer block, to obtain a difference block with difference spectral values; and
processing the quantization block and the difference block to generate coded audio data including information on the quantization block and information on the difference block.
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22. An apparatus for decoding coded audio data having been generated from a time-discrete audio signal by providing a quantization block of spectral values of the time-discrete audio signal quantized using a psychoacoustic model, by inversely quantizing the quantization block and rounding the inversely quantized spectral values to obtain a rounding block of rounded inversely quantized spectral values, by generating of an integer block of integer spectral values using an integer transform algorithm formed to generate the integer block of spectral values from a block of integer time-discrete samples, and by forming a difference block depending on a spectral value-wise difference between the rounding block and the integer block, to obtain a difference block with difference spectral values, comprising:
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a processor for processing the coded audio data to obtain a quantization block and a difference block;
an inverse quantizer for inversely quantizing and rounding the quantization block to obtain an integer inversely quantized quantization block;
a combiner for spectral value-wise combining the integer quantization block and the difference block to obtain a combination block; and
a generator for generating a temporal representation of the time-discrete audio signal using the combination block and using an integer transform algorithm inverse to the integer transform algorithm. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30)
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31. A method of decoding coded audio data having been generated from a time-discrete audio signal by providing, inversely quantizing, generating, forming, and processing, comprising:
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processing the coded audio data to obtain a quantization block and a difference block;
inversely quantizing the quantization block and rounding to obtain an integer inversely quantized quantization block;
spectral value-wise combining the integer quantization block and the difference block to obtain a combination block; and
generating a temporal representation of the time-discrete audio signal using a combination block and using an integer transform algorithm inverse to the integer transformation algorithm.
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32. A computer program with a program code for performing, when the program is executed on a computer, the method of coding a time-discrete audio signal to obtain coded audio data, comprising:
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providing a quantization block of spectral values of a time-discrete audio signal quantized using a psychoacoustic model;
inversely quantizing the quantization block and rounding the inversely quantized spectral values to obtain a rounding block of rounded inversely quantized spectral values;
generating an integer block of integer spectral values using an integer transform algorithm formed to generate the integer block of spectral values from a block of integer time-discrete samples;
forming a difference block depending on a spectral value-wise difference between the rounding block and the integer block, to obtain a difference block with difference spectral values; and
processing the quantization block and the difference block to generate coded audio data including information on the quantization block and information on the difference block.
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33. A computer program with a program code for performing, when the program is executed on a computer, the method of decoding coded audio data having been generated from a time-discrete audio signal by providing, inversely quantizing, generating, forming, and processing, comprising:
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processing the coded audio data to obtain a quantization block and a difference block;
inversely quantizing the quantization block and rounding to obtain an integer inversely quantized quantization block;
spectral value-wise combining the integer quantization block and the difference block to obtain a combination block; and
generating a temporal representation of the time-discrete audio signal using a combination block and using an integer transform algorithm inverse to the integer transformation algorithm.
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Specification