| Patent application number | Description | Published |
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| 20100262420 | AUDIO ENCODER FOR ENCODING AN AUDIO SIGNAL HAVING AN IMPULSE-LIKE PORTION AND STATIONARY PORTION, ENCODING METHODS, DECODER, DECODING METHOD, AND ENCODING AUDIO SIGNAL - An audio encoder for encoding an audio signal includes an impulse extractor for extracting an impulse-like portion from the audio signal. This impulse-like portion is encoded and forwarded to an output interface. Furthermore, the audio encoder includes a signal encoder which encodes a residual signal derived from the original audio signal so that the impulse-like portion is reduced or eliminated in the residual audio signal. The output interface forwards both, the encoded signals, i.e., the encoded impulse signal and the encoded residual signal for transmission or storage. On the decoder-side, both signal portions are separately decoded and then combined to obtain a decoded audio signal. | 10-14-2010 |
| 20110106542 | Audio Signal Decoder, Time Warp Contour Data Provider, Method and Computer Program - An audio signal decoder configured to provide a decoded audio signal representation on the basis of an encoded audio signal representation having a time warp contour evolution information has a time warp contour calculator, a time warp contour data rescaler and a warp decoder. The time warp contour calculator is configured to generate time warp contour data repeatedly restarting from a predetermined time warp contour start value on the basis of a time warp contour evolution information describing a temporal evolution of the time warp contour. The time warp contour data rescaler is configured to rescale at least a portion of the time warp contour data such that a discontinuity at a restart is avoided, reduced or eliminated in a rescaled version of the time warp contour. The warp decoder is configured to provide the decoded audio signal representation on the basis of the encoded audio signal representation and using the rescaled version of the time warp contour. | 05-05-2011 |
| 20110173009 | Apparatus and Method for Encoding/Decoding an Audio Signal Using an Aliasing Switch Scheme - An apparatus for encoding an audio signal includes the windower for windowing a first block of the audio signal using an analysis window having an aliasing portion and a further portion. The apparatus furthermore includes a processor for processing the first sub-block of the audio signal associated with the aliasing portion by transforming the sub-block from a domain into a different domain subsequent to windowing the first sub-block to obtain the processed first sub-block, and for processing a second sub-block of the audio signal associated with the further portion by transforming the second sub-block from the domain into the different domain before windowing the second sub-block to obtain a processed second sub-block. The apparatus furthermore includes a transformer for converting the processed first sub-block and the processed second sub-block from the different domain into a further different domain using the same block transform rule to obtain a converted first block which may then be compressed using any of the well-known data compression algorithms. Thus, a critically sampled switch between two coding modes can be obtained, since aliasing portions occurring in two different domains are matched to each other. | 07-14-2011 |
| 20110178795 | TIME WARP ACTIVATION SIGNAL PROVIDER, AUDIO SIGNAL ENCODER, METHOD FOR PROVIDING A TIME WARP ACTIVATION SIGNAL, METHOD FOR ENCODING AN AUDIO SIGNAL AND COMPUTER PROGRAMS - An audio encoder has a window function controller, a windower, a time warper with a final quality check functionality, a time/frequency converter, a TNS stage or a quantizer encoder, the window function controller, the time warper, the TNS stage or an additional noise filling analyzer are controlled by signal analysis results obtained by a time warp analyzer or a signal classifier. Furthermore, a decoder applies a noise filling operation using a manipulated noise filling estimate depending on a harmonic or speech characteristic of the audio signal. | 07-21-2011 |
| 20110202354 | Low Bitrate Audio Encoding/Decoding Scheme Having Cascaded Switches - An audio encoder has a first information sink oriented encoding branch such as a spectral domain encoding branch, a second information source or SNR oriented encoding branch such as an LPC-domain encoding branch, and a switch for switching between the first encoding branch and the second encoding branch, wherein the second encoding branch has a converter into a specific domain different from the spectral domain such as an LPC analysis stage generating an excitation signal, and wherein the second encoding branch furthermore has a specific domain coding branch such as LPC domain processing branch, and a specific spectral domain coding branch such as LPC spectral domain processing branch, and an additional switch for switching between the specific domain coding branch and the specific spectral domain coding branch. An audio decoder has a first domain decoder such as a spectral domain decoding branch, a second domain decoder such as an LPC domain decoding branch for decoding a signal such as an excitation signal in the second domain, and a third domain decoder such as an LPC-spectral decoder branch and two cascaded switches for switching between the decoders. | 08-18-2011 |
| 20110202355 | Audio Encoding/Decoding Scheme Having a Switchable Bypass - An apparatus for encoding includes a first domain converter, a switchable bypass, a second domain converter, a first processor and a second processor to obtain an encoded audio signal having different signal portions represented by coded data in different domains, which have been coded by different coding algorithms. Corresponding decoding stages in the decoder together with a bypass for bypassing a domain converter allow the generation of a decoded audio signal with high quality and low bit rate. | 08-18-2011 |
| 20110238426 | Audio Decoder, Audio Encoder, Method for Decoding an Audio Signal, Method for Encoding an Audio Signal, Computer Program and Audio Signal - An audio decoder for providing a decoded audio information on the basis of an entropy encoded audio information includes a context-based entropy decoder configured to decode the entropy-encoded audio information in dependence on a context, which context is based on a previously-decoded audio information in a non-reset state-of-operation. The context-based entropy decoder is configured to select a mapping information, for deriving the decoded audio information from the encoded audio information, in dependence on the context. The context-based entropy decoder includes a context resetter configured to reset the context for selecting the mapping information to a default context, which default context is independent from the previously-decoded audio information, in response to a side information of the encoded audio information. | 09-29-2011 |
| 20110313777 | APPARATUS, METHOD AND COMPUTER PROGRAM FOR OBTAINING A PARAMETER DESCRIBING A VARIATION OF A SIGNAL CHARACTERISTIC OF A SIGNAL - An apparatus for obtaining a parameter describing a variation of a signal characteristic of a signal on the basis of actual transform-domain parameters describing the audio signal in transform-domain includes a parameter determinator. The parameter determinator is configured to determine one or more model parameters of a transform-domain variation model describing an evolution of the transform-domain parameters in dependence on one or more model parameters representing a signal characteristic, such that a model error, representing a deviation between a modeled temporal evolution of the transform-domain parameters and an evolution of the actual transform-domain parameters, is brought below a predetermined threshold value or minimized. | 12-22-2011 |
| 20120022881 | AUDIO ENCODER, AUDIO DECODER, ENCODED AUDIO INFORMATION, METHODS FOR ENCODING AND DECODING AN AUDIO SIGNAL AND COMPUTER PROGRAM - An audio decoder for providing a decoded audio information on the basis of an encoded audio information includes a window-based signal transformer configured to map a time-frequency representation, which is described by the encoded audio information, to a time-domain representation. The window-based signal transformer is configured to select a window, out of a plurality of windows including windows of different transition slopes and windows of different transform length, on the basis of a window information. The audio decoder includes a window selector configured to evaluate a variable-codeword-length window information in order to select a window for a processing of a given portion of the time-frequency representation associated with a given frame of the audio information. | 01-26-2012 |
| 20120253797 | MULTI-MODE AUDIO CODEC AND CELP CODING ADAPTED THEREFORE - In an embodiment, bitstream elements of sub-frames are encoded differentially to a global gain value so that a change of the global gain value results in an adjustment of an output level of the decoded representation of the audio content. Concurrently, the differential coding saves bits. Even further, the differential coding enables the lowering of the burden of globally adjusting the gain of an encoded bitstream. In another embodiment, a global gain control across CELP coded frames and transform coded frames is achieved by co-controlling the gain of the codebook excitation of the CELP codec, along with a level of the transform or inverse transform of the transform coded frames. In another embodiment, the gain value determination in CELP coding is performed in the weighted domain of the excitation signal. | 10-04-2012 |
| 20120265541 | AUDIO SIGNAL ENCODER, AUDIO SIGNAL DECODER, METHOD FOR PROVIDING AN ENCODED REPRESENTATION OF AN AUDIO CONTENT, METHOD FOR PROVIDING A DECODED REPRESENTATION OF AN AUDIO CONTENT AND COMPUTER PROGRAM FOR USE IN LOW DELAY APPLICATIONS - An audio signal encoder includes a transform-domain path which obtains spectral coefficients and noise-shaping information on the basis of a portion of the audio content, and which windows a time-domain representation of the audio content and applies a time-domain-to-frequency-domain conversion. The audio signal decoder includes a CELP path to obtain a code-excitation information and a LPD parameter information. A converter applies a predetermined asymmetric analysis window in both if a current portion is followed by a subsequent portion to be encoded in the transform-domain mode or in the CELP mode. Aliasing cancellation information is selectively provided in the later case. | 10-18-2012 |
| 20120271644 | AUDIO SIGNAL ENCODER, AUDIO SIGNAL DECODER, METHOD FOR ENCODING OR DECODING AN AUDIO SIGNAL USING AN ALIASING-CANCELLATION - An audio signal decoder includes a transform domain path configured to obtain a time-domain representation of a portion of an audio content on the basis of a first set of spectral coefficients, a representation of an aliasing-cancellation stimulus signal and a plurality of linear-prediction-domain parameters. The transform domain path applies a spectrum shaping to the first set of spectral coefficients to obtain a spectrally-shaped version thereof. The transform domain path obtains a time-domain representation of the audio content on the basis of the spectrally-shaped version of the first set of spectral coefficients. The transform domain path includes an aliasing-cancellation stimulus filter to filter the aliasing-cancellation stimulus signal in dependence on at least a subset of the linear-prediction-domain parameters. The transform domain path also includes a combiner configured to combine the time-domain representation of the audio content with an aliasing-cancellation synthesis signal to obtain an aliasing reduced time-domain signal. | 10-25-2012 |
| 20130064383 | INFORMATION SIGNAL REPRESENTATION USING LAPPED TRANSFORM - An information signal reconstructor is configured to reconstruct, using aliasing cancellation, an information signal from a lapped transform representation of the information signal including, for each of consecutive, overlapping regions of the information signal, a transform of a windowed version of the respective region, wherein the information signal reconstructor is configured to reconstruct the information signal at a sample rate which changes at a border between a preceding region and a succeeding region of the information signal. | 03-14-2013 |
| 20130117015 | AUDIO SIGNAL DECODER, AUDIO SIGNAL ENCODER, METHOD FOR DECODING AN AUDIO SIGNAL, METHOD FOR ENCODING AN AUDIO SIGNAL AND COMPUTER PROGRAM USING A PITCH-DEPENDENT ADAPTATION OF A CODING CONTEXT - An audio signal decoder includes a context-based spectral value decoder configured to decode a codeword describing one or more spectral values or at least a portion of a number representation thereof in dependence on a context state. The audio signal decoder also includes a context state determinator configured to determine a current context state in dependence on one or more previously decoded spectral values and a time warping frequency-domain-to-time-domain converter configured to provide a time-warped time-domain representation of a given audio frame on the basis of a set of decoded spectral values provided by the context-based spectral value decoder and in dependence on the time warp information. The context-state determinator is configured to adapt the determination of the context state to a change of a fundamental frequency between subsequent audio frames. An audio signal encoder applies a comparable concept. | 05-09-2013 |
| 20130151262 | RESAMPLING OUTPUT SIGNALS OF QMF BASED AUDIO CODECS - An apparatus for processing an audio signal includes a configurable first audio signal processor for processing the audio signal in accordance with different configuration settings to obtain a processed audio signal, wherein the apparatus is adapted so that different configuration settings result in different sampling rates of the processed audio signal. The apparatus furthermore includes an analysis filter bank having a first number of analysis filter bank channels, a synthesis filter bank having a second number of synthesis filter bank channels, a second audio processor being adapted to receive and process an audio signal having a predetermined sampling rate, and a controller for controlling the first number of analysis filter bank channels or the second number of synthesis filter bank channels in accordance with a configuration setting. | 06-13-2013 |
| 20130226596 | APPARATUS AND METHOD FOR LEVEL ESTIMATION OF CODED AUDIO FRAMES IN A BIT STREAM DOMAIN - An apparatus for level estimation of an encoded audio signal is provided. The apparatus has a codebook determinator for determining a codebook from a plurality of codebooks as an identified codebook. The audio signal has been encoded by employing the identified codebook. Moreover, the apparatus has an estimation unit configured for deriving a level value associated with the identified codebook as a derived level value and for estimating a level estimate of the audio signal using the derived level value. | 08-29-2013 |
| 20130241750 | SIGNAL PROCESSOR, WINDOW PROVIDER, ENCODED MEDIA SIGNAL, METHOD FOR PROCESSING A SIGNAL AND METHOD FOR PROVIDING A WINDOW - A signal processor for providing a processed version of an input signal in dependence on the input signal includes a windower configured to window a portion of the input signal, or of a pre-processed version thereof, in dependence on a signal processing window described by signal processing window values for a plurality of window value index values, in order to obtain the processed version of the input signal. The signal processor also includes a window provider for providing the signal processing window values for a plurality of window value index values in dependence on one or more window shape parameters. | 09-19-2013 |
| 20130246492 | SIGNAL PROCESSOR, WINDOW PROVIDER, ENCODED MEDIA SIGNAL, METHOD FOR PROCESSING A SIGNAL AND METHOD FOR PROVIDING A WINDOW - A signal processor for providing a processed version of an input signal in dependence on the input signal has a windower configured to window a portion of the input signal, or of a pre-processed version thereof, in dependence on a signal processing window described by signal processing window values for a plurality of window value index values, in order to obtain the processed version of the input signal. The signal processor also has a window provider for providing the signal processing window values for a plurality of window value index values in dependence on one or more window shape parameters. | 09-19-2013 |
| 20130332148 | APPARATUS AND METHOD FOR ENCODING AND DECODING AN AUDIO SIGNAL USING AN ALIGNED LOOK-AHEAD PORTION - An apparatus for encoding an audio signal having a stream of audio samples has: a windower for applying a prediction coding analysis window to the stream of audio samples to obtain windowed data for a prediction analysis and for applying a transform coding analysis window to the stream of audio samples to obtain windowed data for a transform analysis, wherein the transform coding analysis window is associated with audio samples within a current frame of audio samples and with audio samples of a predefined portion of a future frame of audio samples being a transform-coding look-ahead portion, wherein the prediction coding analysis window is associated with at least the portion of the audio samples of the current frame and with audio samples of a predefined portion of the future frame being a prediction coding look-ahead portion, wherein the transform coding look-ahead portion and the prediction coding look-ahead portion are identically to each other or are different from each other by less than 20%; and an encoding processor for generating prediction coded data or for generating transform coded data. | 12-12-2013 |
| 20130332151 | APPARATUS AND METHOD FOR PROCESSING A DECODED AUDIO SIGNAL IN A SPECTRAL DOMAIN - An apparatus for processing a decoded audio signal including a filter for filtering the decoded audio signal to obtain a filtered audio signal, a time-spectral converter stage for converting the decoded audio signal and the filtered audio signal into corresponding spectral representations, each spectral representation having a plurality of subband signals, a weighter for performing a frequency selective weighting of the filtered audio signal by a multiplying subband signals by respective weighting coefficients to obtain a weighted filtered audio signal, a subtractor for performing a subband-wise subtraction between the weighted filtered audio signal and the spectral representation of the decoded audio signal, and a spectral-time converter for converting the result audio signal or a signal derived from the result audio signal into a time domain representation to obtain a processed decoded audio signal. | 12-12-2013 |
| 20130332174 | AUDIO CODEC SUPPORTING TIME-DOMAIN AND FREQUENCY-DOMAIN CODING MODES - An audio codec supporting both, time-domain and frequency-domain coding modes, having low-delay and an increased coding efficiency in terms of iterate/distortion ratio, is obtained by configuring the audio encoder such that same operates in different operating modes such that if the active operative mode is a first operating mode, a mode dependent set of available frame coding modes is disjoined to a first subset of time-domain coding modes, and overlaps with a second subset of frequency-domain coding modes, whereas if the active operating mode is a second operating mode, the mode dependent set of available frame coding modes overlaps with both subsets, i.e. the subset of time-domain coding modes as well as the subset of frequency-domain coding modes. | 12-12-2013 |
| 20140074486 | APPARATUS AND METHOD FOR AUDIO ENCODING AND DECODING EMPLOYING SINUSOIDAL SUBSTITUTION - An apparatus for generating an audio output signal based on an encoded audio signal spectrum has a processing unit, a pseudo coefficients determiner, a spectrum modification unit, a spectrum-time conversion unit, a controllable oscillator and a mixer. The pseudo coefficients determiner is configured to determine pseudo coefficients of the decoded audio signal spectrum. The spectrum modification unit is configured to set the pseudo coefficients to a predefined value to acquire a modified audio signal spectrum. The spectrum-time conversion unit is configured to convert the modified audio signal spectrum to a time-domain. The controllable oscillator is configured to generate a time-domain oscillator signal and is controlled by the spectral location and the spectral value of at least one of the pseudo coefficients. The mixer is configured to mix the time-domain conversion signal and the time-domain oscillator signal. | 03-13-2014 |
| 20140343953 | MULTI-MODE AUDIO CODEC AND CELP CODING ADAPTED THEREFORE - In an embodiment, bitstream elements of sub-frames are encoded differentially to a global gain value so that a change of the global gain value results in an adjustment of an output level of the decoded representation of the audio content. Concurrently, the differential coding saves bits. Even further, the differential coding enables the lowering of the burden of globally adjusting the gain of an encoded bitstream. In another embodiment, a global gain control across CELP coded frames and transform coded frames is achieved by co-controlling the gain of the codebook excitation of the CELP codec, along with a level of the transform or inverse transform of the transform coded frames. In another embodiment, the gain value determination in CELP coding is performed in the weighted domain of the excitation signal. | 11-20-2014 |
| 20150066488 | TIME WARP ACTIVATION SIGNAL PROVIDER, AUDIO SIGNAL ENCODER, METHOD FOR PROVIDING A TIME WARP ACTIVATION SIGNAL, METHOD FOR ENCODING AN AUDIO SIGNAL AND COMPUTER PROGRAMS - An audio encoder has a window function controller, a windower, a time warper with a final quality check functionality, a time/frequency converter, a TNS stage or a quantizer encoder, the window function controller, the time warper, the TNS stage or an additional noise filling analyzer are controlled by signal analysis results obtained by a time warp analyzer or a signal classifier. Furthermore, a decoder applies a noise filling operation using a manipulated noise filling estimate depending on a harmonic or speech characteristic of the audio signal. | 03-05-2015 |
| 20150066489 | TIME WARP ACTIVATION SIGNAL PROVIDER, AUDIO SIGNAL ENCODER, METHOD FOR PROVIDING A TIME WARP ACTIVATION SIGNAL, METHOD FOR ENCODING AN AUDIO SIGNAL AND COMPUTER PROGRAMS - An audio encoder has a window function controller, a windower, a time warper with a final quality check functionality, a time/frequency converter, a TNS stage or a quantizer encoder, the window function controller, the time warper, the TNS stage or an additional noise filling analyzer are controlled by signal analysis results obtained by a time warp analyzer or a signal classifier. Furthermore, a decoder applies a noise filling operation using a manipulated noise filling estimate depending on a harmonic or speech characteristic of the audio signal. | 03-05-2015 |
| 20150066490 | TIME WARP ACTIVATION SIGNAL PROVIDER, AUDIO SIGNAL ENCODER, METHOD FOR PROVIDING A TIME WARP ACTIVATION SIGNAL, METHOD FOR ENCODING AN AUDIO SIGNAL AND COMPUTER PROGRAMS - An audio encoder has a window function controller, a windower, a time warper with a final quality check functionality, a time/frequency converter, a TNS stage or a quantizer encoder, the window function controller, the time warper, the TNS stage or an additional noise filling analyzer are controlled by signal analysis results obtained by a time warp analyzer or a signal classifier. Furthermore, a decoder applies a noise filling operation using a manipulated noise filling estimate depending on a harmonic or speech characteristic of the audio signal. | 03-05-2015 |
| 20150066491 | TIME WARP ACTIVATION SIGNAL PROVIDER, AUDIO SIGNAL ENCODER, METHOD FOR PROVIDING A TIME WARP ACTIVATION SIGNAL, METHOD FOR ENCODING AN AUDIO SIGNAL AND COMPUTER PROGRAMS - An audio encoder has a window function controller, a windower, a time warper with a final quality check functionality, a time/frequency converter, a TNS stage or a quantizer encoder, the window function controller, the time warper, the TNS stage or an additional noise filling analyzer are controlled by signal analysis results obtained by a time warp analyzer or a signal classifier. Furthermore, a decoder applies a noise filling operation using a manipulated noise filling estimate depending on a harmonic or speech characteristic of the audio signal. | 03-05-2015 |
| 20150066492 | TIME WARP ACTIVATION SIGNAL PROVIDER, AUDIO SIGNAL ENCODER, METHOD FOR PROVIDING A TIME WARP ACTIVATION SIGNAL, METHOD FOR ENCODING AN AUDIO SIGNAL AND COMPUTER PROGRAMS - An audio encoder has a window function controller, a windower, a time warper with a final quality check functionality, a time/frequency converter, a TNS stage or a quantizer encoder, the window function controller, the time warper, the TNS stage or an additional noise filling analyzer are controlled by signal analysis results obtained by a time warp analyzer or a signal classifier. Furthermore, a decoder applies a noise filling operation using a manipulated noise filling estimate depending on a harmonic or speech characteristic of the audio signal. | 03-05-2015 |
| 20150066493 | TIME WARP ACTIVATION SIGNAL PROVIDER, AUDIO SIGNAL ENCODER, METHOD FOR PROVIDING A TIME WARP ACTIVATION SIGNAL, METHOD FOR ENCODING AN AUDIO SIGNAL AND COMPUTER PROGRAMS - An audio encoder has a window function controller, a windower, a time warper with a final quality check functionality, a time/frequency converter, a TNS stage or a quantizer encoder, the window function controller, the time warper, the TNS stage or an additional noise filling analyzer are controlled by signal analysis results obtained by a time warp analyzer or a signal classifier. Furthermore, a decoder applies a noise filling operation using a manipulated noise filling estimate depending on a harmonic or speech characteristic of the audio signal. | 03-05-2015 |
