Digital adaptive transformation coding method
First Claim
1. Digital adaptive transformation coding method for the transmission and/or storage of audio signals, specifically music signals, wherein N scanned values of the audio signal are transformed into M spectral coefficients, wherein N and M are non zero integers, which are subdivided into frequency groups and then quantitized and coded, characterized in that:
- a quantitized maximum value of the spectral coefficients of each frequency group is used to define the coarse variation of the spectrum;
the same number of bits is assigned to all spectrum values of a frequency group, wherein the number of bits depend on the quantitized maximum value of the respective spectral coefficient;
the number of bits assigned to each frequency group being adjusted to insure a minimum number of bits to each frequency group such that, in view of psycho-acoustic aspects, quantification noise is masked for that frequency group; and
if available after the preceding step, any additional number of bits are assigned to the individual frequency groups in correspondence to the quantitized maximum value occurring in the particular frequency group.
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Abstract
A digital adaptive transformation coding method for the transmission and/ortorage of audio signals, specifically music signals, wherein N scanned values of the audio signal are transformed into M spectral coefficients, and the coefficients are split up into frequency groups, quantized and then coded. The quantized maximum value of each frequency group is used to define the coarse variation of the spectrum. The same number of bits is assigned to all values in a frequency group. The bits are assigned to the individual frequency groups as a function of the quantized maximum value present in the particular frequency group. A multi-signal processor system is disclosed which is specifically designed for implementation of this method.
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Citations
10 Claims
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1. Digital adaptive transformation coding method for the transmission and/or storage of audio signals, specifically music signals, wherein N scanned values of the audio signal are transformed into M spectral coefficients, wherein N and M are non zero integers, which are subdivided into frequency groups and then quantitized and coded, characterized in that:
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a quantitized maximum value of the spectral coefficients of each frequency group is used to define the coarse variation of the spectrum; the same number of bits is assigned to all spectrum values of a frequency group, wherein the number of bits depend on the quantitized maximum value of the respective spectral coefficient; the number of bits assigned to each frequency group being adjusted to insure a minimum number of bits to each frequency group such that, in view of psycho-acoustic aspects, quantification noise is masked for that frequency group; and if available after the preceding step, any additional number of bits are assigned to the individual frequency groups in correspondence to the quantitized maximum value occurring in the particular frequency group. - View Dependent Claims (2, 3, 4)
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- 5. Multi-signal processor system, specifically for the transmission and/or storage of audio signals, specifically music signals, wherein N scanned values of the audio signal are transformed into M spectral coefficients, wherein N and M are non zero integers, which are subdivided into frequency groups and then quantitized and coded, characterized in that a quantitized maximum value of the spectral coefficients of each frequency group is used to define the coarse variation of the spectrum, that the same number of bits is assigned to all spectrum values of a frequency group, wherein the number of bits depend on the quantitized maximum value of the respective spectral coefficient, that the number of bits assigned to each frequency group being adjusted to insure a minimum number of bits to each frequency group such that, in view of psycho-acoustic aspects, quantification noise is masked for that frequency group, and that if available after the preceding step, any additional number of bits are assigned to the individual frequency groups in correspondence to the quantitized maximum value occurring in the particular frequency group, comprising several digital signal-processing modules (M1 . . . M4) which process a data flow, e.g. a flow of digitized audio signals, and a location communication channel which handles the data communication between two adjacent modules (M1 . . . M4), characterized in that additionally at least one global communication channel is provided via which system observation, system control, parameter adaptation and/or global data communication are realized.
Specification