Apparatus and method for generating an enhanced signal using independent noise-filling at random values and scaling thereupon

Patent metadata

Field	Value
Publication number	US-11908484-B2
Application number	US-202217648408-A
Country	US
Kind code	B2
Filing date	Jan 19, 2022
Priority date	Jul 28, 2014
Publication date	Feb 20, 2024
Grant date	Feb 20, 2024

Abstract

An apparatus for generating an enhanced signal from an input signal, wherein the enhanced signal has spectral values for an enhancement spectral region, the spectral values for the enhancement spectral regions not being contained in the input signal, includes a mapper for mapping a source spectral region of the input signal to a target region in the enhancement spectral region, the source spectral region including a noise-filling region; and a noise filler configured for generating first noise values for the noise-filling region in the source spectral region of the input signal and for generating second noise values for a noise region in the target region, wherein the second noise values are decorrelated from the first noise values or for generating second noise values for a noise region in the target region, wherein the second noise values are decorrelated from first noise values in the source region.

First claim

The invention claimed is:

1. An apparatus for generating an enhanced signal from an input signal, wherein the enhanced signal comprises spectral values for an enhancement spectral region, the spectral values for the enhancement spectral region not being comprised in the input signal, the apparatus comprising:
a mapper configured for mapping a source spectral region of the input signal to a target region in the enhancement spectral region, wherein, for the target region, a source region identification exists, and wherein the mapper is configured for selecting the source spectral region using the source region identification and for mapping the selected source spectral region to the target region; and
a noise filler configured for generating second noise values for a noise region in the target region in the enhancement spectral region, wherein the second noise values are decorrelated from first noise values in the source spectral region of the input signal,
wherein the source spectral region of the input signal comprises a noise-filling region, wherein the noise filler is configured for: generating the first noise values for the noise-filling region in the source spectral region of the input signal; identifying the noise-filling region comprising the first noise values in the input signal; copying at least a region of the input signal to a source tile buffer, the region comprising the source spectral region, the source spectral region comprising the noise-filling region; and replacing, in the source tile buffer, the first noise values as identified in the identifying the noise-filling region by decorrelated noise values; and wherein the mapper is configured to map the source tile buffer comprising the decorrelated noise values to the target region to acquire the second noise values, or
wherein the source spectral region of the input signal comprises a noise-filling region, and wherein the noise filler is configured for: generating the first noise values for the noise-filling region in the source spectral region of the input signal; identifying noise positions in the noise-filling region in the source spectral region by identifying zero spectral values in the input signal or using noise-filling information from the input signal, or
wherein the noise filler is configured for inserting random values in the target region at noise positions to acquire inserted random values, calculating an energy information on first noise values for the noise-filling region, calculating an energy information on the inserted random values, calculating a scale factor using the energy information on the first noise values and the energy information on the inserted random values, and scaling the inserted random values to acquire the second noise values using multiplying the inserted random values by the scale factor.

2. The apparatus of claim 1 ,
wherein the noise filler is configured to identify noise positions using an identification vector comprising entries for spectral positions in the source spectral region only, or comprising entries for spectral positions in the source spectral region and in the target region.

3. The apparatus of claim 2 , wherein the noise filler is configured for
calculating an energy information on noise values indicated by the identification vector,
calculating an energy information on inserted random values intended for the target region,
calculating a gain factor for scaling the inserted random values, and
applying the gain factor to the inserted random values.

4. The apparatus of claim 1 ,
wherein the mapper is configured to perform a gap filling operation for generating the target region, the apparatus comprising:
a spectral domain audio decoder configured for generating a first decoded representation of a first set of first spectral portions, the decoded representation comprising a first spectral resolution;
a parametric decoder configured for generating a second decoded representation of a second set of second spectral portions comprising a second spectral resolution being lower than the first spectral resolution;
a frequency regenerator configured for regenerating a reconstructed second spectral portion comprising the first spectral resolution using a first spectral portion and spectral envelope information for the second spectral portion; and
a spectrum time converter configured for converting the first decoded representation in the reconstructed second spectral portion into a time representation,

wherein the mapper and the noise filler are at least partly comprised in the frequency regenerator.

5. The apparatus of claim 4 ,
wherein the spectral domain audio decoder is configured to output a sequence of decoded frames of spectral values, a decoded frame being the first decoded representation, wherein the frame comprises spectral values for the first set of spectral portions and zero indications for the second set of second spectral portions,
wherein the apparatus for decoding further comprises a combiner for combining spectral values generated by the frequency regenerator for the second set of second spectral portions and spectral values of the first set of first spectral portions in a reconstruction band to acquire a reconstructed spectral frame comprising spectral values for the first set of the first spectral portions and the second set of the second spectral portions; and
wherein the spectrum-time converter is configured to convert the reconstructed spectral frame into the time representation.

6. The apparatus of claim 1 ,
wherein the input signal is an encoded signal comprising noise-filling parameters for the source spectral region of the input signal,
wherein the noise filler is configured for generating the first noise values using the noise-filling parameters and for generating the second noise values using an energy information on the first noise values.

7. The apparatus of claim 1 ,
wherein the noise filler is configured to measure an energy information on the decorrelated noise values and to measure an energy information on the first noise values and to scale the decorrelated noise values using a scaling value derived from the energy information on the decorrelated noise values and the energy information on the first noise values.

8. The apparatus of claim 1 ,
wherein the noise filler is configured for generating the second noise values subsequent to an operation of the mapper, or
wherein the noise filler is configured for generating the first noise values and the second noise values subsequent to an operation of the mapper.

9. The apparatus of claim 1 ,
wherein the noise filler is configured
to perform noise-filling in spectral regions by generating the first noise values using a noise-filling operation and noise-filling parameters transmitted in the input signal as side information, and
to perform a noise-filling operation in the target region to generate the second noise values using energy information on the first noise values.

10. The apparatus of claim 1 , further comprising:
an envelope adjuster configured for adjusting the second noise values in the enhancement spectral region using spectral envelope information comprised in the input signal as side information.

11. The apparatus of claim 1 ,
wherein the noise filler is configured to only use side information of the input signal to identify spectral positions for a noise-filling operation, or
wherein the noise filler is configured to analyze a time or spectral characteristic of the input signal with or without spectral values in the noise-filling region to identify spectral positions for the noise-filling operation.

12. The apparatus of claim 1 ,
wherein t

Assignees

• Fraunhofer Ges Forschung

Inventors

• Disch Sascha
• Geiger Ralf
• Niedermeier Andreas
• Neusinger Matthias
• Schmidt Konstantin
• Wilde Stephan
• Schubert Benjamin
• Neukam Christian

Classifications

• G10L25/21

  the extracted parameters being power information · CPC title

• G10L21/038

  using band spreading techniques · CPC title

• G10L19/028 Primary

  Noise substitution, i.e. substituting non-tonal spectral components by noisy source (comfort noise for discontinuous speech transmission G10L19/012) · CPC title

• G10L19/0204 Primary

  using subband decomposition · CPC title

• G10L15/20

  Speech recognition techniques specially adapted for robustness in adverse environments, e.g. in noise, of stress induced speech (G10L21/02 takes precedence) · CPC title