RU2512090C2 - Apparatus and method of generating wide bandwidth signal - Google Patents

Abstract

FIELD: physics, acoustics.

SUBSTANCE: invention relates to audio signal processing devices. An input signal is presented for a first band with first resolution data and for a second band with second resolution data, the second resolution being lower than the first resolution. A patch generator generates a first patch from the first band of the input signal according to a first patch generation algorithm and generates a second patch from the first band of the input signal according to a second patch generation algorithm. Spectral density of the second patch generated according to the second patch generation algorithm is higher than the spectral density of the first patch generated according to the first patch generation algorithm. A coupler merges the first patch, the second patch and the first band of the input signal to obtain a wide bandwidth signal. The apparatus for generating a wide bandwidth signal scales the input signal according to the first patch generation algorithm and according to the second patch generation algorithm or scales the first patch and the second patch such that the wide bandwidth signal satisfies the spectrum envelope criterion.

EFFECT: wider bandwidth of an audio signal.

18 cl, 19 dwg

Description

Embodiments according to the invention relate to processing an audio signal, and in particular, to an apparatus and method for generating an extended bandwidth signal from an input signal, a device and a method for producing a signal with reduced bandwidth based on an input signal and an audio signal.

Perceptually adapted coding of audio signals, which provides a significant reduction in the data rate for efficient storage and transmission of these signals, has been widely used in many fields. Many coding algorithms are known, for example MPEG 1/2 Layer 3 ("MP3") or MPEG 4 AAC (Advanced Audio Coding). However, the encoding used for this, especially when operating at the lowest bit rates, can lead to a deterioration in subjective sound quality, which is often caused mainly by the forced limitation of the bandwidth of the audio signal to be transmitted on the side of the encoder.

As is known from WO 9857436, in order to subject the audio signal to band limitation in such a situation on the encoder side and to encode only the lower band of the audio signal, a high-quality audio encoder (“main encoder”) is used. The upper band, however, is characterized only very roughly, that is, by a number of parameters that reproduce the envelope of the spectrum of the upper band. Then on the decoder side the upper band is synthesized. To this end, harmonic movement is proposed, where the lower band of the decoded audio signal is fed to the filter bank. The channels of the low pass filter bank are connected to the channels of the high filter bank or are “patched”, and each paid signal with a limited frequency band is subjected to envelope control. The synthesizing filter bank belonging to the filter bank for special analysis receives signals with a limited frequency band of the audio signal in the lower band and signals with a limited frequency band subjected to the control of the envelope of the lower band, which are harmoniously inserted into the upper band. The output of the synthesizing filter bank is an audio signal expanded with respect to its original passband, which is transmitted from the encoder to the decoder by the main encoder operating at a very low data rate. In particular, calculating the filter bank and inserting a patch in the area of the filter bank can be very time consuming.

Simplified methods for expanding the bandwidth of limited band audio signals instead use the low-frequency portions of the signal (LF-H4) to copy to the high-frequency range (HP-HF) to approximate information that is missing due to bandwidth limitation. Such methods are described in the work of M. Dietz, L. Lillerid, K. Kierling and O. Kunts, “Spectral band replication, a new approach to sound coding”, at the 112th AES Congress (Society of Sound Engineers), Munich, May 2002 g .; by S. Meltzer, R. Behm, and F. Henn, “Enhanced Audio Codecs with SBR (RBR - Buffer Memory Register) for Digital Broadcasting, such as World Digital Radio (DRM)”, at the 112th Congress AES, Munich, May 2002; in the work of T. Ziegler, A. Eret, P. Ekstrand and M. Lutsky, “Improving tr3 with SBR: Characteristics and capabilities of the new mp3PRO algorithm”, at the 112th AES Congress, Munich, May 2002; International Standard ISO / IEC 14496-3: 2001 / FPDAM 1, “Bandwidth Expansion”, ISO / IEC, 2002, or “Method and apparatus for expanding speech bandwidth”, Vasu Iyengar et al. US Patent No. 5455888.

In these methods, harmonic movement is not performed, but sequential signals with a limited frequency band of the lower band are introduced into the serial channels of the filter bank of the upper band. Thus, a rough approximation of the upper band of the audio signal is achieved. In the next step, this rough approximation of the signal is assimilated relative to the original by post-processing using control information received from the original signal. Here, for example, scale factors are used to adapt the envelope of the spectrum, to reverse filter, and to add a minimum noise level to adapt the tonality, and to complement the sinusoidal parts of the signal for missing harmonics, as also described in the MPEG-4 standard. High-performance advanced sound coding (NOT- AAS).

In addition, further methods use a phase vocoder to expand bandwidth. When using a phase vocoder for spectral expansion, the frequency lines move farther apart. If there are gaps in the spectrum, for example, as a result of quantization, then they even increase with expansion. With energy adaptation, the remaining lines in the spectrum receive too much energy compared to the corresponding lines in the original signal.

FIG. 13 shows a schematic illustration of a bandwidth extension 1300 by using a phase vocoder. In this example, two patches 1312, 1314 are added to the low frequency signal band 1302. The suppressed RF component 1320 of the signal, also called the crossover frequency (Xover), is the low frequency of the adjacent patch 1312, and the double crossover frequency (x-over frequency) is the suppressed RF component of the neighboring patch 1312 and the suppressed low frequency component of the next patch 1314. The phase vocoder doubles the frequency of the frequency lines of the low-frequency signal band 1302 to obtain the adjacent patch 1312, and triples the frequencies of the frequency lines of the low-frequency signal band 1302 to obtain the next patch 1314. Therefore, the spectral band tnost neighboring patch 1312 - only half of the spectral density of the low frequency band 1302 of the signal and the spectral density of the next patch 1314 is only one third of the spectral density of the low frequency band 1302 of the signal.

The concentration of energy in the bands (patches) only up to several frequency lines leads to a significant change in timbre, which differs from the original. The energy of the previous larger number of bands (frequency lines) is summed up on the smaller number of remaining ones.

Some examples of phase vocoders and their applications are presented in the work of Frederick Nagel and Sasha Disch, “A Method for Harmoniously Extending Bandwidth for Audio Codec Decoders,” ICASSP '09, and in M. Puckett's “Phase Locked Vocoder.” IEEE ASSP Processing Application Conference sound and acoustic signals, Mohonck 1995 ", in the work of Rebel, A .:" Transient detection and storage in a phase vocoder "; citeseer.ist.psu.edu/679246.html, in the work of Larosh L., Dolson M .: “Improved modification of the time scale of sound obtained by means of a phase vocoder”, IEEE. Trans, Speech and Sound Processing, Vol. 7, No. 3, pp. 323-332 and US Pat. No. 6,549,884.

One approach to filling gaps is shown in WO 00/45379. It contains a method and apparatus for expanding source coding systems using high frequency recovery. This application solves the problem of insufficient noise content in the restored high range by adaptively adding a minimum noise level. Adding noise can fill in the gaps, but sound quality or subjective quality may not significantly improve.

The objective of the invention is to provide a concept for expanding the bandwidth of audio signals, which improves the subjective quality of signals with extended bandwidth.

This is achieved by using the device according to paragraphs 1 and 11 of the patent claims, an audio signal according to paragraph 14 and the method according to paragraphs 15 and 16.

The implementation of the invention provides a device for generating a signal with an expanded bandwidth from the input signal. An input signal is provided for the first band by the first resolution data and for the second band by the second resolution data; the second resolution is lower than the first resolution. The device includes a patch generator and combiner. A patch generator is generated to generate a first patch from the first strip of the input signal according to the first patch algorithm, and is formed to generate a second patch from the first strip of the input signal according to the second patch algorithm. The spectral density of the second patch generated according to the second patch creation algorithm is higher than the spectral density of the first patch generated according to the first patch creation algorithm. A combiner is formed to combine the first patch, the second patch, and the first input signal band to obtain an extended bandwidth signal. A device for generating a signal with a wider bandwidth is formed to scale the input signal according to the first algorithm for creating “patches” and according to the second algorithm for creating a “patches”, or to scale the first patch and the second patch so that the signal with the extended bandwidth satisfies the criterion of the envelope of the spectrum.

Implementations according to this invention are based on the central idea that a patch with a low spectral density (which means, for example, that the patch includes gaps in comparison with the low-frequency band of the input signal) is combined with a patch with a high spectral density (which means, for example, that the patch includes only a few gaps or does not include gaps at all compared to the low-frequency band of the input signal) to expand the bandwidth of the input signal. Since both patches are generated based on the input signal, high-frequency bandwidth expansion of the low-frequency band of the input signal can provide a good approximation of the original audio signal. Additionally, the first and second patches can be scaled before (by scaling the input signal) or after generation to satisfy the spectral envelope criterion, since the spectral envelope of the original audio signal must be taken into account when restoring the high-frequency band of the input signal. Thus, the subjective quality or sound quality of an extended bandwidth signal can be significantly improved.

In some implementations according to the invention, the first patch generation algorithm is a harmonic patch generation algorithm. In other words, the first patch is generated so that only frequencies that are integer multiples of the frequencies of the first band of the input signal are contained in the first patch. In addition, the second patch generation algorithm may be a mixing patch generation algorithm. This means, for example, that a second patch can be generated so that the second patch contains frequencies that are integer multiples of the frequencies of the first band of the input signal and frequencies that are not integer multiples of the frequencies of the first band of the input signal. Therefore, the spectral density of the second patch is higher than the spectral density of the first patch. By combining the first patch and the second patch, the missing frequency lines of the first patch can be filled with the frequency lines of the second patch. Thus, the intervals of harmonic bandwidth expansion according to the first “patch” creation algorithm can be filled with a second patch, and the sound quality of the extended bandwidth signal can be significantly improved.

Some implementations according to the invention relate to a device for receiving a signal with a reduced bandwidth based on the input signal. The device includes a spectral envelope determinant, a patch scaling control data generator, and an output interface. The spectral envelope data determiner is formed to determine the spectral envelope data based on the high frequency band of the input signal. A patch scaling control data generator is generated to generate patch scrolling control data for scaling a signal with a reduced bandwidth in a decoder, or for scaling a first patch and a second patch with a decoder so that the expanded bandwidth signal generated by the decoder satisfies the spectral envelope criterion. The spectral envelope criterion is based on the data of the spectral envelope. The first patch is generated from the low-frequency band of the signal with a reduced bandwidth according to the first “patch” algorithm, and the second patch is generated from the low-frequency band of the signal with a reduced bandwidth according to the second “patch” algorithm. The spectral density of the second patch generated according to the second patch creation algorithm is higher than the spectral density of the first patch generated according to the first patch creation algorithm. An output interface is configured to combine the low frequency band of the input signal, the spectral envelope data and the power scaling control data to obtain a signal with a reduced bandwidth. Further, an output interface is configured to receive a signal with a reduced bandwidth for transmission or storage.

Some further implementations according to the invention relate to an audio signal comprising a first band and a second band. The first strip is represented by the first resolution data, and the second strip is represented by the second resolution data. The second resolution is lower than the first resolution. The second resolution data is based on the second-band spectrum envelope data and the second-band patch scaling control data for scaling the audio signal in the decoder or for scaling the first and second patches by the decoder so that the extended bandwidth signal generated by the decoder satisfies the spectral envelope criterion. The spectral envelope criterion is based on the data of the spectral envelope. The first patch is generated from the first strip of the audio signal according to the first patch algorithm, and the second patch is generated from the first strip of the audio signal according to the second patch algorithm. The spectral density of the second patch generated according to the second patch creation algorithm is higher than the spectral density of the first patch generated according to the first patch creation algorithm.

Implementations according to the invention will subsequently be considered in more detail with reference to the attached drawings, in which:

Figure 1 - block diagram of a device for generating a signal with extended bandwidth from the input signal;

Figure 2a is a schematic illustration of a generated first patch;

Fig.2b is a schematic illustration of the generated first and second patches;

Figa - block diagram of a device for generating a signal with an expanded bandwidth from the input signal;

Fig. 3b is a schematic illustration of a limited level sinusoidal input signal;

Fig. 3c is a schematic illustration of a half-wave rectified sinusoidal input signal;

Fig. 3d is a schematic illustration of a wave rectified sinusoidal input signal with a limited level;

4 is a block diagram of a device for generating a signal with an expanded bandwidth from the input signal;

Fig. 5a is a schematic illustration of a filter bank of a phase vocoder;

Fig. 5b is a detailed illustration of the filter of Fig. 5a;

Fig. 5c is a schematic illustration of manipulating a signal with amplitude coding and a signal with frequency coding in the filter channel of Fig. 5a;

6 is a schematic illustration of a phase vocoder transform;

7 is a block diagram of a device for generating a signal with an expanded bandwidth from the input signal;

Fig. 8 is a block diagram of an apparatus for generating an extended bandwidth signal from an input signal;

Fig.9 is a block diagram of a device for generating a signal with an expanded bandwidth from the input signal;

Figure 10 is a block diagram of a device for receiving a signal with a reduced bandwidth based on the input signal;

11 is a flowchart of a method for generating an extended bandwidth signal from an input signal;

12 is a flowchart of a method for obtaining a signal with a reduced bandwidth based on an input signal;

13 is a schematic illustration of a known bandwidth expansion algorithm.

Hereinafter, the same reference numbers are partially used for objects and functional units having the same or similar functional properties, and their description regarding the number should also be applied to other numbers in order to reduce redundancy in the description of implementations.

FIG. 1 shows a block diagram of an apparatus 100 for generating an extended bandwidth signal 122 for an input signal 102 according to an embodiment of the invention. An input signal 102 is provided for the first band with first resolution data and for the second band with second resolution data; the second resolution is lower than the first resolution. The device 100 includes a patch generator 110 connected to a combiner 120. A patch generator 120 generates a first patch 112 from a first strip of an input signal 102 according to a first patch generating algorithm and generates a second patch 114 from a first strip of an input signal 102 according to a second patch generating algorithm . The spectral density of the second patch 114 generated according to the second patch creation algorithm is higher than the spectral density of the first patch 112 generated according to the first patch creation algorithm. The combiner 120 combines the first patch 112, the second patch 114, and the first strip of the input signal 102 to obtain an extended bandwidth signal 122. Next, the device 100 for generating the extended bandwidth signal 122 scales the input signal 102 according to the first “patch” generation algorithm and according to the second “patch” creation algorithm, or scales the first patch 112 and the second patch 114 so that the signal with the extended passband 122 satisfies the spectral envelope criterion.

Spectral density means, for example, the density of different frequencies or frequency lines within a frequency range. For example, a frequency range from 0 Hz to 10 kHz, including frequency parts with frequencies of 4 kHz and 8 kHz, has a lower spectral density than the same frequency range, including frequency parts with frequencies of 2 kHz, 4 kHz, 6 kHz, 8 kHz and 10 kHz. Since the spectral density of the first patch 112 is lower than the spectral density of the second patch 114, the first patch 112 includes gaps in comparison with the second patch 114. Therefore, the second patch 114 can be used to fill these gaps. Since both patches are based on the first band of the input signal 102, both patches are associated with the characteristic of the original signal corresponding to the input signal 102. Therefore, the signal with extended passband 122 can be a good approximation of the original signal, and the subjective quality or sound quality of the signal with extended passband 122 can be greatly improved by using the described concept. Thus, more energy can be distributed between the remaining lines and, for example, unnatural sound can be avoided.

For example, the first patch creation algorithm may be a harmonic patch creation algorithm. Therefore, the patch generator 110 can generate a first patch 112 including only frequencies that are integer multiples of the frequencies of the first band of the input signal 102. Harmoniously expanding the bandwidth can provide a good approximation of the tonal structure of the original signal, but this “patch” algorithm will leave gaps between the harmonic frequencies . These spaces may be filled with a second patch. For example, the second patch generation algorithm may be a patch patch mixing algorithm, which means that the patch generator 110 can generate a second patch 114 including integer multiples of the frequencies of the first band of the input signal 102 (harmonic frequencies) and frequencies that are not integer multiples of the frequencies of the first band of the input signal 102 (non-harmonic frequencies). Non-harmonic frequencies can be used to fill the gaps of the first patch 112. You can also combine the whole second patch 114 (including harmonic frequencies) with the first patch 112. In this example, the amplification of harmonic frequencies as a result of combining the harmonic frequency parts of the first patch 112 and the second patch 114 can be taken into attention by appropriately scaling the first patch 112 and / or the second patch 114.

The first patch 112 and the second patch 114 include at least partially the same frequency range. For example, the first patch 112 includes a frequency range from 4 kHz to 8 kHz, and the second patch 114 includes a frequency range from 6 kHz to 10 kHz. In some embodiments of the invention, the suppressed low frequency component of the frequency of the first patch is equal to the suppressed low frequency component of the frequency of the second patch, and the suppressed high frequency component of the frequency of the first patch 112 is equal to the high frequency suppressed component of the second patch 114. For example, both patches include a frequency range from 4 kHz up to 8 kHz.

Figures 2a and 2b show an example of a first patch 112 according to the first patch creation algorithm 212 and a second patch 114 according to the second patch creation algorithm 214. For a better illustration, FIG. 2a shows only the first patches 112, and FIG. 2b shows the first patches 112 and corresponding second patches 114. FIG. 2a illustrates an example 200 for a first strip 202 of an input signal 102 and two first patches 112 generated according to a first “patch” generating algorithm 212. In this example, the patch includes the same bandwidth as the first lane 202 in a single signal 102. The bandwidth may also be different. The suppressed RF component 220 of the first band 202 of the input signal 102 is indicated by a frequency of “Xover” (crossover frequency). In the example shown in FIG. 2a, patches start at a frequency equal to a multiple of the crossover frequency of Xover 220. The frequency lines within the first patches 112 are integer multiples of the frequency lines of the first band 202 of the input signal 102 and can, for example, be generated by a phase vocoder. These first patches 112 include gaps in terms of missing frequency lines compared to the first strip 202 of the input signal 102.

FIG. 2b further shows an example 250 of two corresponding second patches 114. These patches are generated according to the second patching algorithm 214 and include harmonic and non-harmonic frequencies. Non-harmonic frequency lines can be used to fill the gaps of the first patches 112. The frequency lines of the second patches 114 can be generated, for example, by non-linear distortion.

Thus, the gaps can be filled not arbitrarily, as, for example, when filling the gaps with noise. The gaps are filled based on the first resolution data of the first band of the input signal and, therefore, based on the original signal.

The first strip of the input signal 102 may represent, for example, the low frequency band of the original high resolution encoded audio signal. The second band of the input signal 102 may represent, for example, a high-frequency band of the original audio signal and may be quantized by one or more parameters such as spectrum envelope data, noise data, and / or missing low-resolution harmonic data. The original audio signal may be, for example, an audio signal recorded by a microphone prior to processing or encoding.

Scaling the input signal according to the first patch creation algorithm and according to the second patch creation algorithm means, for example, that the input signal is scaled once according to the first patch creation algorithm before the first patch is generated, and then the first patch is generated based on a scaled input signal, and that the input signal is scaled once according to the second “patch” algorithm before the second patch is generated, and then the second patch is generated, basing Referring to the scaled input signal, so that after combination of the first patch, the second patch and the first band input signal with extended bandwidth satisfy the spectral envelope criterion. Alternatively, the first patch and the second patch are scaled after they are generated so that the extended bandwidth signal also satisfies the spectral envelope criterion. It is also possible to scale the input signal according to the first “patch” creation algorithm and according to the second “patch” creation algorithm together with scaling of the first patch and the second patch.

Combiner 120 may be, for example, an adder, and the extended bandwidth signal 122 may be the weighted sum of the first patch 112, the second patch 114, and the first strip of the input signal 102.

Satisfying the spectral envelope criterion means, for example, that the spectral envelope of the extended bandwidth signal is based on the data of the spectral envelope contained in the input signal. Spectral envelope data may be generated by an encoder and may represent a second band of the original signal. Thus, the spectral envelope of an extended bandwidth signal can be a good approximation of the spectral envelope of the original signal.

The device 100 may also include a main decoder for decoding the first strip of the input signal 102.

The patch generator 110 and combiner 120 may, for example, be specially designed hardware or part of a processor or microcontroller, or may be a computer program configured to run on a computer or microcontroller. The device 100 may be part of a decoder or audio decoder.

FIG. 3a shows a block diagram of an apparatus 300 for generating an extended bandwidth signal 122 from an input signal 102 according to an embodiment of the invention. In this example, patch generator 110 includes a phase vocoder 310 for generating a first patch and an amplitude limiter 320 to generate a second patch 114. Phase vocoder 310 and amplitude limiter 320 are connected to combiner 120. Phase vocoder 310 can expand the first strip of audio input signal 102 to generate a first patch 112 including harmonic frequencies. In the non-linear processing step, an amplitude limiter 320 may limit the input signal 102 to generate a second patch 114 including harmonic and non-harmonic frequencies. Alternative to the amplitude limiter 320, also a half-wave rectifier, wave rectifier, mixer or diode used in the square region of the characteristic curve can be used to generate non-harmonic frequencies based on the input signal 102, in the non-linear processing stage.

3b, 3c and 3d show examples of a level-limited signal and / or a rectified input signal 102 for generating non-harmonic frequencies. Fig. 3b shows a schematic illustration 350 of a sinusoidal input signal with a level limit of 102. When the signal is limited, break points appear in the form of sharp changes in the slope of the signal 380, and harmonic and non-harmonic parts with higher frequencies are generated.

Alternatively, FIG. 3c shows a schematic illustration 360 of a half-wave rectified sinusoidal input signal 102 also causing break points 380.

Further, a combination of restriction and rectification is possible. FIG. 3d shows a schematic illustration 370 of a level-limiting signal and a wave rectified sinusoidal input signal 102, causing various break points 380.

By limiting and / or rectifying or using other non-linear processing methods of the producing break point 380, a wide range of different frequencies can be generated. Therefore, a patch generated according to such a patch creation algorithm may have a high spectral density.

4 shows a block diagram of an apparatus 400 for generating an extended bandwidth signal 122 from an input signal 102 according to an embodiment of the invention. The device 400 is similar to the device shown in FIG. 3a, but further includes a spectral line selector 410. A phase vocoder 310 and an amplitude limiter 320 are connected to a spectral line selector 410, and a spectral line selector 410 is connected to a combiner 120. The spectral line selector 410 can select multiple frequency lines of the second patch 114 to obtain an altered second patch 414, which may be additional to the first patch. The frequency line of the second patch 114 can be selected if there is no corresponding frequency line of the first patch 112. In other words, the spectral line selector 410 selects the frequency lines of the second patch 114 to fill the gaps of the first patch 112 and can ignore the frequencies of the second patch 114 already in the first patch 112. Thus, the modified second patch 414 may include gaps in the frequencies already contained in the first patch 112.

In this example, combiner 120 combines the first patch 112, the modified second patch 414, and the first strip of the input signal 102.

The spectral line selector 410 may be, for example, part of a patch generator 110 (as shown in FIG. 4) or a separate unit.

Hereinafter, with reference to FIGS. 5 and 6, possible embodiments of a phase vocoder 310 according to the present invention are shown. Fig. 5a shows a design of a filter bank of a phase vocoder, where an audio signal is input 500 and is output 510. In particular, each channel of the schematic filter bank illustrated in Fig. 5a includes a bandpass filter 501 and a subsequent oscillator 502. The output signals of all oscillators from each channel are combined by a combiner, which, for example, is executed as an adder and is indicated by the number 503 to obtain an output signal. Each filter 501 is implemented in such a way that it provides an amplitude-coded signal on the one hand and a frequency-coded signal on the other. The amplitude-coded signal and the frequency-coded signal are time signals illustrating the increase in amplitude in the filter 501 over time, while the frequency-coded signal represents an increase in the frequency of the signal filtered by the filter 501.

A schematic diagram of a filter 501 is illustrated in FIG. 5b. Each filter 501 of FIG. 5a can be located as in FIG. 5b, where, however, only the frequencies f _i supplied to the two input mixers 551 and the adder 552 differ from channel to channel. The mixed outputs of the mixers 551 are both filtered by low-pass filters 553, where the low-frequency signals are different because they were generated by the local oscillator frequencies (LO frequencies), which are 90 ° out of phase. The upper lowpass filter 553 provides a quadrature signal 554, while the lower filter 553 provides a phase-matching signal 555. These two signals, that is, Q and I, are supplied to a coordinate transformer 556, which generates an amplitude-phase representation from a rectangular representation. 5a, the magnitude signal or amplitude signal is output over time at the output 557. A phase signal is supplied to the device for unfolding phase 558. At the output of element 558 there is no longer any phase value that is always between 0 and 360 °, but there is a phase value, which increases linearly. This “expanded” phase value is supplied to the phase / frequency converter 559, which, for example, can be implemented as a simple phase difference calculator that subtracts the phase of the previous point in time from the phase at a given point in time to obtain the frequency value for a given point in time , or any other means to obtain an approximation of the phase derivative. This frequency value is added to the constant frequency value f _{i of} the filter channel i to obtain a time-varying frequency value at the output 560. The frequency value at the output 560 has a constant component equal to f _i and a variable component equal to the frequency deviation at which this frequency the signal in the filter channel deviates from the average frequency f _i .

Thus, as illustrated in FIGS. 5a and 5b, the phase vocoder achieves the separation of spectral information and time information. The spectral information is contained in a special channel or in the frequency f _i , which provides a direct part of the frequency for each channel, while the temporal information is contained in the frequency deviation or in the evolution of magnitude over time, respectively.

Fig. 5c shows the manipulation of how it is performed to generate the first patch according to the invention, in particular by using a phase vocoder 310 and, in more detail, inserted where the dashed lines of the illustrated circuit in Fig. 5a are located.

To scale the time, for example, the amplitude signals A (t) in each channel or the frequency of the signals f (t) in each channel can be reduced by 10 times or interpolated. In order to move, since it is useful for the present invention, interpolation is performed, i.e., temporarily expanding or propagating the signals A (t) and f (t) to obtain propagation signals A '(t) and f (t), where the interpolation is controlled by a factor Propagation 598. The propagation factor can be selected, for example, so that the phase vocoder generates harmonic frequencies. By interpolating the phase change, that is, the value before adding the constant frequency to the adder 552, the frequency of each individual oscillator 502 in FIG. 5a does not change. A temporary change in the overall sound signal is slowed down, however, by factor 2. The result is a time-distributed tone that has an original main tone, that is, the original main wave with its harmonics.

By performing the signal processing illustrated in FIG. 5c, the audio signal can be reduced to its original duration, for example, by decimating factor 2, while all frequencies are doubled at the same time. This leads to the movement of the fundamental tone by factor 2, where, however, an audio signal is obtained that has the same length as the original audio signal, that is, the same number of samples.

As an alternative to performing the filter bank illustrated in FIG. 5 a, phase vocoder conversion may also be performed as shown in FIG. 6. Here, an audio signal 698 is supplied to the FFT processor, or more generally, to the short-term Fourier transform processor (STFT) 600 as a sequence of time samples. The FFT 600 processor is implemented to temporarily process the audio signal by the window method, and then, using the subsequent FFT, calculate the magnitude spectrum and also the phase spectrum, where this calculation is performed for successive spectra that are connected to blocks of the audio signal that overlap strongly.

In the extreme case, a new spectrum can be calculated for each new sample of the sound signal, where a new spectrum can also be calculated, for example, only for every twentieth new sample. This distance 'a' in the samples between the two spectra is preferably made by the controller 602. The controller 602 is further implemented to provide an IFFT (fast inverse Fourier transform) processor 604, which is implemented to perform the superimposing-adding operation. In particular, the IFFT 604 processor is implemented in such a way that it performs the inverse short-term Fourier transform by performing one IFFT per spectrum based on the magnitude spectrum and phase spectrum, in order to then perform the superimposing-adding operation to obtain the resulting time signal. The overlay - add operation is performed to eliminate the blocking action entered by the analysis window.

Temporal propagation of the time signal is achieved by the distance 'b' between the two spectra, since they are processed by the IFFT 604 processor, which is greater than the distance 'a' between the spectra used to generate the FFT spectra. The basic idea is to propagate the audio signal by simply placing the inverse FFTs farther apart than the analyzing FFTs. As a result, spectral changes in the synthesized sound signal occur more slowly than in the original sound signal.

Without changing the phase scale in block 606, however, this will lead to the occurrence of frequency artifacts. When, for example, one single frequency resolution element is considered for which successive phase values of 45 ° are performed, this implies that the signal within this filter bank increases in phase at a rate of 1/8 cycle, i.e. 45 ° per time interval, where the time interval is the time interval between successive FFTs. If the reverse FFTs are now located farther apart, this means that a 45 ° increase in phase occurs over a longer time interval. This means that the frequency of this part of the signal has been unintentionally changed. To eliminate this artifact, the phase scale is changed by the same factor by which the audio signal propagated in time. The phase of each FFT spectral value is thus increased by a factor b / a so as to eliminate this unintended frequency modification.

While in the embodiment illustrated in FIG. 5c, the propagation by interpolation of the amplitude / frequency control signals was achieved for one signal oscillator in the filter bank of FIG. 5a, the propagation in FIG. 6 is achieved by the distance between the two IFFT spectra, which is greater than the distance between the two FFT spectra, that is, 'b' is greater than 'a', where, however, to prevent the appearance of an artifact, the phase scale is changed according to the ratio 'b / a'. The distance 'b' can be chosen, for example, so that the phase vocoder generates harmonic frequencies.

7 shows a block diagram of an apparatus 700 for generating an extended bandwidth signal 122 from an input signal 102 according to an embodiment of the invention. The device 700 is similar to the device shown in FIG. 1, but includes a power controller 710, a first power control device 720 and a second power control device 730. A power controller 710 is connected to a first power control device 720 and a second power control device 730. The first control device power 720 and a second power control device 730 are connected to the patch generator 110. The power controller 710 can control the scaling of the input signal according to the first and second algorithm creating "patches", based on the data of the spectral envelope contained in the input signal, and based on the control patches of scaling the data contained in the input signal. Alternatively, instead of the patch scaling control data contained in the input signal, at least one stored patch scaling control parameter may be used. The patch scaling control parameter may be stored in the memory of the patch scaling control parameter, which may be part of the power controller 710 or a separate unit. The first power control device 720 can scale the input signal 102 according to the first patch algorithm, and the second power control device 730 can scale the input signal 102 according to the second patch algorithm. In other words, the input signal 102 can be pre-processed so that the first and second patches can be generated so that the extended-bandwidth signal satisfies the spectral envelope criterion. For this, the spectral envelope data can determine the spectral envelope of the extended bandwidth signal 122, and the patch scaling control data or the patch scaling control parameter can establish a relationship between the first patch 112 and the second patch 114 or can set the absolute values of the first patch 112 and / or the second patch 114. The first power control device 720 and the second power control device 730 may be part of a power controller 710 or separate units, as shown in phi .7. The power controller 710 may be part of the patch generator 110 or a separate unit, as also shown in Fig.7. Power control devices 720, 730 may be, for example, amplifiers or filters controlled by a power controller 710.

Alternatively, scaling is performed after the patches are generated. Accordingly, FIG. 8 shows a block diagram of an apparatus 800 for generating an extended bandwidth signal 122 from an input signal 102 according to an embodiment of the invention. The device 800 is similar to the device shown in FIG. 7, but the power control devices 720, 730 are located between the patch generator 110 and the combiner 120. In this example, the patch generator 110 is connected to the first power control device 720 and connected to the second power control device 730. The first the power control device 720 and the second power control device 730 are connected to the combiner 120. Thus, the first patch 112 can be scaled by the first power control device 720 according to vomu algorithm creating a "patch", and the second patch 114 may be scaled by the second power control device 730 according to a second algorithm creating a "patch". The power control devices controlled by the power controller 710 are again based on spectrum envelope data and on the patch scaling control data or the patch scaling control parameter, as described above.

Alternatively, it is also possible to scale or adjust the power of only one of the two patches, followed by combining the patches by combiner 120 and scaling the combined patches to combine the combined patches with the first input signal range 102. In other words, at first one patch can be scaled to realize a predetermined ratio (for example, based on patch scaling control data) between two patches, and then the combined patches are scaled (e.g., based on spectral envelope data) to satisfy the spectral envelope criterion.

The patch scaling control data may include, for example, a simple factor or a plurality of parameters for scaling a power distribution. The patch scaling control data may indicate, for example, the power ratio between the first patch and the second patch in the full second band or full high frequency band or the absolute value of the power of the first patch and / or second patch in the full second band or full high frequency band, and can be represented, at least one parameter. Alternatively, the patch scaling data includes a factor for each of a plurality of subbands constituting a second band or a high frequency band, for example, similar to spectral envelope data for a subband when applying spectral bandwidth replication. Alternatively, patch scaling data may also show the transfer function of the filter. For example, the parameters of the filter transfer function for scaling the first patch and / or the parameters of the filter transfer function for scaling the second patch may be contained in the input signal. Thus, the parameters can represent a function of frequency. Another alternative may be patch control parameters representing the differential function of the first patch and the second patch. According to these examples, scaling of the input signal or scaling of the first patch and the second patch can be based on the patch scaling control data including at least one parameter.

FIG. 9 shows a block diagram of an apparatus 900 for generating an extended bandwidth signal 122 from an input signal 102 according to an embodiment of the invention. The device 900 is similar to the device shown in FIG. 8, but further includes a noise combiner 910, a missing harmonic combiner 920, a noise power control device 940 and a power control device for the missing harmonics 950. A noise combiner 910 is connected to a noise power control device 940, which connected to the combiner 120. The missing harmonic combiner 920 is connected to the power control device for the missing harmonics 950, which is connected to the combiner 120. Further, the power regulator 710 is connected to the regulator noise power 940 and the power control device for the missing harmonics 950. The noise adder 910 can generate a noise patch 912 based on the noise data contained in the input signal 102.

The noise patch 912 can be scaled by the noise power control device 940. The power controller 710 can control the noise power control device 940 based on spectral envelope data and / or noise scaling data contained in the input signal 102. Thus, the noise of the original signal can be approximated, to improve the sound quality of the extended bandwidth signal.

The missing harmonic adder 920 may generate a missing harmonic patch 922 based on the missing harmonic data contained in the input signal. The missing harmonic patch 922 may contain harmonic frequencies that can only appear in the high-frequency band of the original signal and therefore cannot be reproduced if only the low-frequency band of the original signal is available in terms of the first band of the input signal 102. The data of the missing harmonics can provide information about these missing harmonics. The missing harmonic patch 922 can be scaled by the missing harmonic power control device 950. The power controller 710 can control the missing harmonic power control device 950 based on spectral envelope data or based on scaling data of the missing harmonics contained in the input signal 102.

Combiner 120 may combine a first patch 112, a second patch 114, a first input signal band 102, a noise patch 912, and a missing harmonic patch 922 to provide an extended bandwidth signal 122. A power controller 710 in combination with a power control device can scale the first patch 112 a second patch 114, a noise patch 912, and a missing harmonic patch 922 based on the spectral envelope data, so as to satisfy the spectral envelope criterion.

10 shows a block diagram of an apparatus 1000 for receiving a signal with a reduced bandwidth 1032 based on an input signal 1002 according to an embodiment of the invention. The device 1000 includes a spectral envelope data determiner 1010, a patch scaling control data generator 1020, and an output interface 1030. A spectral envelope data determiner 1010, and a patch scaling control data generator 1020 are connected to an output interface 1030. A spectral envelope data determiner 1010 may determine spectrum envelope data 1012, based on the high frequency band of the input signal 1002. The scaling control data generator of the patch 1020 can generate the scanned control data A patch 1022 for scaling a signal with a reduced bandwidth 1032 in a decoder or for scaling a first patch and a second patch with a decoder so that the extended bandwidth signal produced by the decoder satisfies the spectral envelope criterion. The spectral envelope criterion is based on the data of the spectral envelope. The first patch is generated from the first signal band with a reduced bandwidth 1032 according to the first “patch” algorithm, and the second patch is generated from the first band of the signal with a reduced bandwidth 1032 according to the second “patch” algorithm. The spectral density of the second patch generated according to the second patch creation algorithm is higher than the spectral density of the first patch generated according to the first patch creation algorithm. The output interface 1030 combines the low frequency band of the input signal 1002, the envelope data of the spectrum 1012, and the scaling control data of the patch 1022 to obtain a signal with a reduced bandwidth 1032. Further, the output interface 1030 provides a signal with a reduced bandwidth 1032 for transmission or storage.

Apparatus 1000 may also include a primary encoder for encoding a low frequency band of an input signal. The primary encoder may be, for example, a differential encoder, an entropy encoder, or a perceptual audio encoder.

The device 1000 may be part of an encoding device configured to provide a signal for the decoder described above. The scaling control data of the patch 1022 may include, for example, a simple factor or a plurality of parameters for scaling the power distribution. The patch scaling control data can show, for example, the power ratio between the first patch and the second patch in the full high-frequency band or the absolute value of the power of the first patch and / or second patch in the full high-frequency band and can be represented by at least one parameter. Alternatively, the patch scaling data includes a factor defined for each of the plurality of subbands forming the high frequency band, for example, similar to the spectral envelope data for the subband when applying spectral bandwidth replication. Alternatively, patch scaling data may also show the transfer function of the filter. For example, the parameters of the filter transfer function for scaling the first patch and / or the parameters of the filter transfer function for scaling the second patch can be determined in order to generate patch scaling control data. Thus, parameters can be generated based on the frequency function. Another alternative may be generated by patch scaling control parameters representing the differential function of the first patch and the second patch.

Patch scaling control data 1022 can be generated by analyzing the input signal 1002 and selecting the patch scaling control parameters stored in the memory of the patch scaling control parameter based on the analysis of the input signal 1002 to obtain patch scaling control data 1022.

Alternatively, the generation of scaling control data for the patch 1022 may be implemented by a synthesis analysis method. To do this, the patch scaling control data generator 1020 may further include a patch generator (as described for the decoder) and a comparator. The patch generator may generate a first patch from the low frequency band of the input signal 1002 according to the first patch generating algorithm, and a second patch from the low frequency band of the input signal 1002 according to the second patch creating algorithm. The spectral density of the second patch generated according to the second patch creation algorithm may be higher than the spectral density of the first patch generated according to the first patch creation algorithm. The comparator can compare the first patch, the second patch, and the high-frequency band of the input signal to obtain the scaling control data of the patch 1022. In other words, the concept described above also applies to the device 1000. Thus, the device 1000 can extract the scaling control data of the patch 1022 by comparing patches or combining patches with an input signal, which may, for example, be an original audio signal. Additionally, the device 1000 may also include a spectral line selector, a power regulator, a noise combiner and / or a combiner of missing harmonics, as described above. Thus, also the noise data controlling the noise patch scaling data, the missing harmonic data, and / or the scaling control data of the missing harmonic patches can be extracted by a synthesis analysis method.

Some embodiments of the invention relate to an audio signal including a first band and a second band. The first strip is represented by the first resolution data, and the second strip is represented by the second resolution data, where the second resolution is lower than the first resolution. The second resolution data is based on the second-band spectrum envelope data and the second-band patch scaling control data for scaling the audio signal in the decoder or for scaling the first and second patches with the decoder so that the extended-bandwidth signal produced by the decoder satisfies the spectral envelope criterion. The spectral envelope criterion is based on the data of the spectral envelope. The first patch is generated from the first strip of the audio signal according to the first patch algorithm, and the second patch is generated from the first strip of the audio signal according to the second patch algorithm. The spectral density of the second patch generated according to the second patch creation algorithm is higher than the spectral density of the first patch generated according to the first patch creation algorithm.

The audio signal may be, for example, a signal with a reduced bandwidth based on the original audio signal. The first band of the audio signal may represent the low frequency band of the original high resolution encoded audio signal. The second band of the audio signal can represent the high-frequency band of the original audio signal and can be quantized with at least two parameters: the spectral envelope parameter represented by the spectral envelope data and the patch scaling control parameter represented by the patch scaling control data. Based on such an audio signal, a decoder according to the concept described above can generate an extended bandwidth signal providing a good approximation of the original audio signal with improved sound quality compared to known concepts.

11 shows a flow diagram of a method 1100 for generating an enhanced bandwidth signal from an input signal according to an embodiment of the invention. The input signal is presented for the first band with data of the first resolution and for the second band with data of the second resolution, the second resolution is lower than the first resolution. Method 1100 includes generating a first patch 1110, generating a second patch 1120, scaling an input signal 1130, or scaling a first patch and a second patch 1130, and combining a first patch, a second patch, and a first input band 1140 to obtain an extended bandwidth signal. The first patch is generated 1110 from the first strip of the input signal according to the first patch algorithm, and the second strip is generated 1120 from the first strip of the input signal according to the second patch algorithm. The spectral density of the second patch generated 1120 according to the second patch creation algorithm is higher than the spectral density of the first patch generated 1110 according to the first patch creation algorithm. The input signal may be scaled 1130 according to the first patch generation algorithm and according to the second patch generation algorithm, or the first patch and second patch may be scaled 1130 so that the extended bandwidth signal satisfies the spectral envelope criterion.

Further, method 1100 can be expanded in steps according to the concept described above. Method 1100 can, for example, be implemented as a computer program to run on a computer or microcontroller.

12 shows a flowchart of a method 1200 for providing a reduced bandwidth signal based on an input signal according to an embodiment of the invention. The method 1200 includes determining 1210 spectrum envelope data based on a high frequency band of an input signal, generating 1220 patch scaling control data, combining 1230 low frequency input band, envelope data and patch scaling control data to obtain a reduced bandwidth signal, and providing 1240 signal with reduced bandwidth for transmission or storage. Patch scaling control data is generated 1220 to scale the signal with reduced bandwidth in the decoder or to scale the first patch and second patch by the decoder so that the extended bandwidth signal generated by the decoder satisfies the spectral envelope criterion. The spectral envelope criterion is based on the data of the spectral envelope. The first patch is generated from the low-frequency band of the signal with a reduced bandwidth according to the first “patch” algorithm, and the second patch is generated from the low-frequency band of the signal with a reduced bandwidth according to the second “patch” algorithm. The spectral density of the second patch generated according to the second patch creation algorithm is higher than the spectral density of the first patch generated according to the first patch creation algorithm.

Further, method 1200 can be expanded in steps according to the concept described above. Method 1200 may, for example, be implemented as a computer program to run on a computer or microcontroller.

Some implementations according to the invention relate to a device for generating a signal with extended bandwidth by using a phase vocoder to expand the bandwidth combined with non-linear distortion or noise filling to obtain a denser spectrum. When using a phase vocoder for spectral propagation, the frequency lines move further apart. If there are gaps in the spectrum, for example, as a result of quantization, they even increase during propagation. With energy adaptation, the remaining lines in the spectrum receive too much energy. This is prevented by filling the gaps with either noise or further harmonics that can be obtained by non-linear signal distortion. Thus, more energy can be distributed between the remaining lines. When energy is concentrated in the bands on only a few frequency lines, an unnatural or metallic sound arises. The energy of the pre-existing more bands is collected on the remaining.

If there are no gaps in the spectrum, but at least noise is present, part of the energy remains at a minimum noise level. When applying nonlinear distortion, the spectrum can again be densified, on the one hand, by the noise produced by the distortion, on the other hand, by further harmonic parts controlled by the appropriate selection of the signal part to be distorted.

The extended bandwidth signal can then be, for example, the weighted sum of the filtered distorted signal and the signal that was generated using the phase vocoder. In other words, an extended bandwidth signal can be a weighted sum of the first patch, second patch, and first input band.

Some embodiments of the invention relate to a concept suitable for all audio applications where full bandwidth is not available. For example, to transmit audio content via radio using digital radio services, an Internet stream, or other audio communication applications, the concept described may be used.

When describing this invention in terms of several implementations, there are changes, permutations, and equivalents that are within the scope of this invention. It should also be noted that there are many alternative methods for implementing the methods and structures of the present invention. Therefore, it is assumed that the following claims are interpreted as including all such changes, permutations, and equivalents that are within the true essence and scope of this invention.

In particular, it is indicated that, depending on the conditions, an inventive scheme may also be implemented in software. The execution may be on a digital storage medium, in particular on a floppy disk or CD, with electronically readable control signals capable of interacting with a programmable computer system so that the corresponding method is implemented. Typically, the invention also consists of a computer program product with a control program stored on a computer-readable medium for performing an inventive method when the computer program product is executed on a computer. In other words, the invention can also be implemented as a computer program with a control program for executing a method when the computer program product is executed on a computer.

Claims (18)

1. A device (100; 300; 400; 700; 800; 900) for generating a signal with an extended passband (122) from the input signal (102), where the input signal is presented for the first band with data of the first resolution and for the second band with data of the second resolution ; the second resolution is lower than the first resolution; including a patch generator (110) configured to generate a first patch (112) from the first strip of the input signal (102) according to the first algorithm for creating patches, and a second patch (114) from the first strip of the input signal (102) according to the second creation algorithm Patch, where the spectral density of the second patch (114) generated according to the second patch creation algorithm is higher than the spectral density of the first patch (112) generated according to the first patch creation algorithm; and a combiner (120) configured to combine the first patch (112), the second patch (114) and the first input signal band (102) to obtain an extended bandwidth signal (122), where the device for generating the extended bandwidth signal configured to scale the input signal (102) according to the first patch creation algorithm and according to the second patch creation or scaling algorithm of the first patch (112) and the second patch (114) so that the extended bandwidth signal is satisfied ryal (122) spectral envelope criterion. 2. The device according to claim 1, where the first algorithm for creating patches is a harmonic algorithm for creating patches, and the patch generator (110) is configured to generate the first patch (112) so that only frequencies that are integer multiples of the frequencies of the first the input signal bands (102) were contained in the first patch (112). 3. The device according to claim 1, where the second algorithm for creating patches is a mixing algorithm for creating patches, and the patch generator (110) is configured to generate a second patch (114) so that the second patch (114) contains frequencies that are integer multiples of the frequencies of the first band of the input signal (102), and contain frequencies that are not integer multiples of the frequencies of the first band of the input signal (102). 4. The device according to claim 1, where the suppressed LF component of the first patch (112) is equal to the suppressed LF component of the second patch (114), and where the suppressed HF component of the first patch (112) is equal to the suppressed RF component of the second patch (114) . 5. The device according to claim 1, includes a phase vocoder (310), configured to generate a first patch (112) according to the first algorithm for creating “patches”. 6. The device according to claim 1, includes an amplitude limiter (320), configured to generate a second patch (114) according to the second algorithm for creating “patches” by limiting the first strip of the input signal (102). 7. The device according to claim 1, includes a spectral line selector (410), configured to select a plurality of frequency lines of the second patch (114) to obtain a modified second patch (414), where the frequency line is selected if the frequency line corresponding to the selected frequency line is not included in the first patch (112) as generated by the patch generator (110), where a combiner (120) is configured to combine the first patch (112), the modified second patch (414) and the first input signal strip (102). 8. The device according to claim 1, includes a power controller (710), configured to control the scaling of the input signal (102) according to the first and second algorithm for creating “patches” or to control the scaling of the first patch (112) and the second patch (114), where a power controller 710 controls scaling based on spectral envelope data contained in the input signal (102) and based on at least one stored patch scaling control parameter or patch scaling control data containing REGARD in the input signal (102). 9. The device according to claim 8, includes a first power control device (720), configured to scale the input signal (102) according to the first “patch” algorithm or to scale the first patch (112), and includes a second power control device (730 ), configured to scale the input signal (102) according to the second patch creation algorithm or to scale the second patch (114), where the power controller (710) is configured to control the first power control device (72 0) and a second power control device (730). 10. The device according to claim 8, includes a noise combiner (910) and a missing harmonic combiner (920), where the noise combiner (910) is configured to generate a noise patch (912) based on the noise data contained in the input signal, where the combiner the missing harmonics (920) is configured to generate the missing harmonic patch (922) based on the missing harmonic data contained in the input signal (102), where the power controller (710) is configured to control the scaling of the noise patch (912) and the missing harmonic patch (922) based on spectral envelope data, and where combiner (120) is configured to combine the first patch (112), the second patch (114), the first input signal band (102), the noise patch (912), and the missing harmonic patch (922) to receive an extended bandwidth signal (122), where the power controller 710 controls the scaling of the first patch (112), the second patch (114), the noise patch (912) and the missing harmonic patch (922) based on the data spectral envelope so that the ogee criterion is satisfied ayuschey spectrum. 11. An apparatus (1000) for providing a signal with a reduced bandwidth (1032) based on an input signal (1002), including a spectral envelope determinant (1010), is configured to determine spectral envelope data (1012) based on a high frequency input band signal (1002); a patch scaling control data generator (1020) is configured to generate a patch scaling control data (1022) for scaling a signal with a reduced bandwidth (1032) in a decoder or for scaling a first patch and a second patch with a decoder so that the extended bandwidth signal is generated by a decoder, satisfying the spectral envelope criterion, where the spectral envelope criterion is based on the spectral envelope data (1012), where the first patch is generated from the first signal band with a reduced bandwidth (1032) according to the first patch generation algorithm, and a second patch is generated from the first signal band with a reduced bandwidth (1032) according to the second patch generation algorithm, where the spectral density of the second patch generated according to the second creation algorithm A patch is higher than the spectral density of the first patch generated according to the first patch creation algorithm; the output interface (1030) is configured to combine the low frequency band of the input signal (1002), the spectral envelope data (1012) and the patch scaling control data (1022) to obtain a signal with a reduced bandwidth (1032) and generated to provide a signal with a reduced bandwidth (1032) for transmission or storage. 12. The device according to claim 11, where the patch scaling control data generator includes a patch generator, configured to generate a first patch from a low frequency band of an input signal (1002) according to a first “patch” algorithm and generate a second patch from a low frequency band of an input signal (1002 ) according to the second patching algorithm, where the spectral density of the second patch generated according to the second patching algorithm is higher than the spectral density of the first patch is generated oh algorithms according to the first creating a "patch"; and the comparator is configured to compare the first patch, the second patch, and the high frequency band of the input signal (1002) to obtain patch scaling control data (1022). 13. The device according to claim 11, including the memory of the patch scaling control parameter, is configured to save and provide a plurality of patch scaling control parameters, where the patch scaling control data generator (1020) is configured to analyze an input signal (1002) and generate scaling control data patches (1022) based on stored patch scaling control parameters selected based on analysis of the input signal (1002). 14. A computer-readable storage medium with an audio signal stored on it, including the first band represented by the first resolution data; and a second band represented by second resolution data, where the second resolution is lower than the first resolution, where the second resolution data is based on the spectral envelope data of the second band and is based on the second band patch scaling control data for scaling the audio signal in the decoder or for scaling the first patch and the second patch by the decoder so that the extended-bandwidth signal generated by the decoder satisfies the spectral envelope criterion, where the spectral envelope criterion based on spectral envelope data, where the first patch is generated from the first strip of the audio signal according to the first patch algorithm, and the second patch is generated from the first strip of the audio signal according to the second patch algorithm, where the spectral density of the second patch generated according to the second algorithm the creation of patches, higher than the spectral density of the first patch generated according to the first algorithm for creating patches. 15. The method (1100) of generating a signal with an extended bandwidth from the input signal, where the input signal is presented for the first band with data of the first resolution, and for the second band with data of the second resolution; the second resolution is lower than the first resolution; comprising generating (1110) a first patch from a first input signal band according to a first “patch” algorithm; generating (1120) a second patch from the first strip of the input signal according to the second patch algorithm, where the spectral density of the second patch generated according to the second patch algorithm is higher than the spectral density of the first patch generated according to the first patch algorithm ; scaling (1130) the input signal according to the first patch-creating algorithm and according to the second patch-creating algorithm, or scaling (1130) the first patch and second patch so that the extended-bandwidth signal satisfies the spectral envelope criterion; and combining (1140) a first patch, a second patch, and a first input signal band to obtain an extended bandwidth signal. 16. A method (1200) for providing a signal with a reduced bandwidth based on an input signal, comprising: determining (1210) spectrum envelope data based on a high frequency band of an input signal; generating (1220) patch scaling control data for scaling the signal with reduced bandwidth in the decoder or scaling the first patch and second patch with the decoder so that the extended bandwidth signal generated by the decoder satisfies the spectral envelope criterion, where the spectral envelope criterion is based on envelope data spectrum, where the first patch is generated from the first signal band with a reduced bandwidth according to the first algorithm for creating "patches", and the second the patch is generated from the first signal bandwidth with a reduced bandwidth according to the second patch algorithm, where the spectral density of the second patch generated according to the second patch algorithm is higher than the spectral density of the first patch generated according to the first patch algorithm; combining (1230) the low frequency band of the input signal, the spectral envelope data and the patch scaling control data to obtain a signal with a reduced bandwidth; providing (1240) a signal with a reduced bandwidth for transmission or storage. 17. A computer-readable storage medium with a computer program stored thereon with program code for performing the method of claim 15, when the computer program is running on a computer or microcontroller. 18. A computer-readable storage medium with a computer program stored on it with program code for performing the method according to clause 16, when the computer program is running on a computer or microcontroller.

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