Patent application number | Description | Published |
20100145692 | METHODS AND ARRANGEMENTS IN A TELECOMMUNICATIONS NETWORK - The present invention relates to a postfilter and a postfilter control to be associated with a postfilter for improving perceived quality of speech reconstructed at a speech decoder. The postfilter control comprises means for measuring stationarity of a speech signal reconstructed at a decoder, means for determining a coefficient to a postfilter control parameter based on the measured stationarity, and means for transmitting the determined coefficient to a postfilter, such that the postfilter can process the reconstructed speech signal by applying the determined coefficient to the postfilter control parameter to obtain an enhanced speech signal. | 06-10-2010 |
20110119039 | Objective Measurement of Audio Quality - In an apparatus for objective perceptual evaluation of speech quality, parameters BandwidthRef and BandwidthTest representing the bandwidth are forwarded to a calculator | 05-19-2011 |
20110153336 | MULTI-MODE SCHEME FOR IMPROVED CODING OF AUDIO - The present invention relates to an improved scheme for coding of audio. In particular, the present invention relates to an encoder device and a method for coding an input signal in an encoder system. The method comprises applying a first mode to the input signal to form a first output and applying a second mode to the input signal to form a second output. A first processed output is then formed from at least a part of the first output, and a second processed output is formed from at least a part of the second output. Forming a second processed output comprises estimating a part of the input signal from at least a part of the second output. Then, an optimum mode is determined based on the firstprocessedoutput and the secondprocessedoutput, and the output according to the optimum mode is selected. | 06-23-2011 |
20110282656 | Method And Arrangement For Processing Of Audio Signals - Method and decoder for processing of audio signals. The method and decoder relate to deriving a processed vector {circumflex over (d)} by applying a post-filter directly on a vector d comprising quantized MDCT domain coefficients of a time segment of an audio signal. The post-filter is configured to have a transfer function H which is a compressed version of the envelope of the vector d. A signal waveform is reconstructed by performing an inverse MDCT transform on the processed vector {circumflex over (d)}. | 11-17-2011 |
20110295599 | Aligning Scheme for Audio Signals - Methods, devices, and computer programs described herein may segment a reference signal that corresponds to a non-degraded signal into a plurality of reference signal segments; generate filter coefficients based on each reference signal segment; and filter each reference signal segment with its corresponding generated filter coefficients. The methods, devices, and computer programs may also filter a degraded signal, which includes a delayed signal of the reference signal, with each of the generated filtering coefficients to produce a number of degraded signals equivalent to a number of the plurality of reference signal segments; perform time-wise alignment for each filtered degraded signal with respect to each corresponding filtered reference signal segment; and output a time offset based on the performing. | 12-01-2011 |
20110313758 | Method and Arrangement for Processing of Speech Quality Estimate - Method and arrangement for processing of a speech quality estimate, which involve adaption of a speech quality estimate based on information related to the bandwidth of a reference signal used when determining said speech quality estimate, such that the adapted speech quality estimate is independent of the bandwidth of the reference signal. The method and arrangement enable objective speech quality measurements or assessments to be performed on a unified bandwidth scale, independent of the bandwidth of a reference signal, which allows e.g. a more relevant comparison of communication systems and/or equipment, such as e.g. codecs. | 12-22-2011 |
20120020484 | Audio Signal Quality Prediction - Method and apparatus for predicting the quality of an audio signal after transmission through a communication system ( | 01-26-2012 |
20120069888 | Method and Arrangement for Estimating the Quality Degradation of a Processed Signal - An objective quality assessment method for obtaining an improved estimate of a perceptual quality degradation of a processed signal, and an arrangement for executing such a method, is provided, which is executed on a processed signal and an associate reference signal. Both signals are split up into associated frame-pairs after into frames which either all or selected frame-pairs are processed further, by creating a reference residual signal and a processed residual signal for each frame-pair, calculating separate ratios of p-norms on both residual signals, and by calculating and storing a per-frame frame-pair quality estimate on the basis of the ratios of p-norms for each selected frame-pair. An objective per-signal quality estimate that is proportional to the perceptual quality Create degradation is then provided by aggregating the calculated per-frame-pair quality estimates. | 03-22-2012 |
20120116759 | Method, Computer, Computer Program and Computer Program Product for Speech Quality Estimation - The invention relates to a method, computer, computer program and computer program product for speech quality estimation. The method comprises the steps of: determining a coding distortion parameter (Q | 05-10-2012 |
20120221326 | Methods and Arrangements for Loudness and Sharpness Compensation in Audio Codecs - In a method of improving perceived loudness and sharpness of a reconstructed speech signal delimited by a predetermined bandwidth, performing the steps of providing (S | 08-30-2012 |
20120230515 | BANDWIDTH EXTENSION OF A LOW BAND AUDIO SIGNAL - Estimation of a high band extension of a low band audio signal includes the following steps: extracting (S | 09-13-2012 |
20120239388 | EXCITATION SIGNAL BANDWIDTH EXTENSION - An apparatus for generating a high band extension of a low band excitation signal (e | 09-20-2012 |
20120278085 | METHOD AND A DECODER FOR ATTENUATION OF SIGNAL REGIONS RECONSTRUCTED WITH LOW ACCURACY - The embodiments of the present invention improves conventional attenuation schemes by replacing constant attenuation with an adaptive attenuation scheme that allows more aggressive attenuation, without introducing audible change of signal frequency characteristics. | 11-01-2012 |
20130006646 | Transform Audio Codec and Methods for Encoding and Decoding a Time Segment of an Audio Signal - Methods and devices for efficient encoding/decoding of a time segment of an audio signal. Methods comprise deriving an indicator, z, of the position in a frequency scale of a residual vector associated with the time segment of the audio signal, and deriving a measure, Φ, related to the amount of structure of the residual vector. The methods further comprise determining whether a predefined criterion involving the measure Φ, the indicator z and a predefined threshold Θ, is fulfilled, which corresponds to estimating whether a change of sign of at least some of the non-zero coefficients of the residual vector would be audible after reconstruction of the audio signal time segment. The amplitude of the coefficients of the residual vector is encoded, and the signs of the coefficients of the residual vector are encoded only when it is determined that the criterion is fulfilled, and thus that a change of sign would be audible. | 01-03-2013 |
20130044647 | BANDWIDTH EXTENSION IN A MULTIPOINT CONFERENCE UNIT - A multipoint conference unit includes input/output ports to communicate with at least three client terminals via at least three communication channels with each communication channel communicating with one of the at least three client terminals, a memory to store data streams communicated between multipoint conference unit and the client terminals, and a processor to mix data streams received from the client terminals and to store the mixed data streams in the memory. The processor also determines a number of each of three different types of communication channels and selectively implements bandwidth extension to the communication channels based on the determination. | 02-21-2013 |
20130132075 | METHODS AND ARRANGEMENTS IN A TELECOMMUNICATIONS NETWORK - The present invention relates to a postfilter and a postfilter control to be associated with a postfilter for improving perceived quality of speech reconstructed at a speech decoder. The postfilter control comprises means for measuring stationarity of a speech signal reconstructed at a decoder, means for determining a coefficient to a postfilter control parameter based on the measured stationarity, and means for transmitting the determined coefficient to a postfilter, such that the postfilter can process the reconstructed speech signal by applying the determined coefficient to the postfilter control parameter to obtain an enhanced speech signal. | 05-23-2013 |
20130317811 | Efficient Encoding/Decoding of Audio Signals - A method for encoding of an audio signal comprises performing ( | 11-28-2013 |
20130339038 | Post-Quantization Gain Correction in Audio Coding - A gain adjustment apparatus ( | 12-19-2013 |
20130346087 | Filling of Non-Coded Sub-Vectors in Transform Coded Audio Signals - A spectrum filler for filling non-coded residual sub-vectors of a transform coded audio signal includes a sub-vector compressor ( | 12-26-2013 |
20140046658 | FRAME BASED AUDIO SIGNAL CLASSIFICATION - An audio classifier for frame based audio signal classification includes a feature extractor configured to determine, for each of a predetermined number of consecutive frames, feature measures representing at least the following features: auto correlation, frame signal energy, inter-frame signal energy variation. A feature measure comparator is configured to compare each determined feature measure to at least one corresponding predetermined feature interval. A frame classifier is configured to calculate, for each feature interval, a fraction measure representing the total number of corresponding feature measures that fall within the feature interval, and to classify the latest of the consecutive frames as speech if each fraction measure lies within a corresponding fraction interval, and as non-speech otherwise. | 02-13-2014 |
20140081646 | Method and a Decoder for Attenuation of Signal Regions Reconstructed with Low Accuracy - The embodiments of the present invention improves conventional attenuation schemes by replacing constant attenuation with an adaptive attenuation scheme that allows more aggressive attenuation, without introducing audible change of signal frequency characteristics. | 03-20-2014 |
20140114667 | Transform Audio Codec and Methods for Encoding and Decoding a Time Segment of an Audio Signal - Methods and devices for efficient encoding/decoding of a time segment of an audio signal. The methods comprise deriving an indicator, z, of the position in a frequency scale of a residual vector associated with the time segment of the audio signal, and deriving a measure, Φ, related to the amount of structure of the residual vector. The methods further comprise determining whether a predefined criterion involving the measure Φ, the indicator z and a predefined threshold Θ, is fulfilled, which corresponds to estimating whether a change of sign of at least some of the non-zero coefficients of the residual vector would be audible after reconstruction of the audio signal time segment. The respective amplitude of the coefficients of the residual vector is encoded, and the signs of the coefficients of the residual vector are encoded only when it is determined that the criterion is fulfilled, and thus that a change of sign would be audible. | 04-24-2014 |
20140249808 | Methods and Arrangements in a Telecommunications Network - The present invention relates to a postfilter and a postfilter control to be associated with a postfilter for improving perceived quality of speech reconstructed at a speech decoder. The postfilter control comprises means for measuring stationarity of a speech signal reconstructed at a decoder, means for determining a coefficient to a postfilter control parameter based on the measured stationarity, and means for transmitting the determined coefficient to a postfilter, such that the postfilter can process the reconstructed speech signal by applying the determined coefficient to the postfilter control parameter to obtain an enhanced speech signal. | 09-04-2014 |
20140249828 | Audio Encoding/Decoding based on an Efficient Representation of Auto-Regressive Coefficients - Described is an encoder ( | 09-04-2014 |
20140257827 | GENERATION OF A HIGH BAND EXTENSION OF A BANDWIDTH EXTENDED AUDIO SIGNAL - An audio decoder configured to generate a high band extension of an audio signal from an envelope and an excitation. The audio decoder includes a control arrangement configured to jointly control envelope shape and excitation noisiness with a common control parameter (f). | 09-11-2014 |
20140288925 | BANDWIDTH EXTENSION OF AUDIO SIGNALS - Audio decoder and method therein for supporting bandwidth extension (BWE) of a received signal. The method involves receiving a first signal representing the lower frequency spectrum of a segment of an original audio signal; receiving a second signal, being a BWE signal, representing a higher frequency spectrum of the segment of the original audio signal. The method further comprises determining a degree of voicing in the lower frequency spectrum of the audio signal, based on the received first signal; and selecting a spectral tilt adaptation filter, out of at least two spectral tilt adaptation filters having different spectral attenuation characteristics, based on the determined degree of voicing. The selected spectral tilt adaptation filter is then applied on the received second signal. Thus, a differentiation of spectral tilt in the higher frequency spectrum of a reconstructed audio signal, based on lower frequency spectrum characteristics of the original audio signal is enabled. | 09-25-2014 |
20150046171 | Transform Encoding/Decoding of Harmonic Audio Signals - An encoder ( | 02-12-2015 |
20150051907 | VECTOR QUANTIZER - Vector Quantizer and method therein for efficient vector quantization, e.g. in a transform audio codec. The method comprises comparing an input target vector s with a plurality of centroids, each centroid representing a respective class of codevectors in a codebook. Further, a starting point for a search related to the input target vector in the codebook is determined, based on the result of the comparison. The codevectors in the codebook are sorted according to a distortion measure reflecting the distance between each codevector and the centroids of the classes. The Vector Quantizer and method enables that the class of codevectors comprising the most probable candidate codevectors in regard of the input vector. s may be searched first. | 02-19-2015 |
20150088527 | BANDWIDTH EXTENSION OF HARMONIC AUDIO SIGNAL - Methods and arrangements in a codec for supporting bandwidth extension, BWE, of an harmonic audio signal. The method in the decoder part of the codec comprises receiving a plurality of gain values associated with a frequency band b and a number of adjacent frequency bands of band b. The method further comprises determining whether a reconstructed corresponding frequency band b′ comprises a spectral peak. When the band b′ comprises a spectral peak, a gain value associated with the band b′ is set to a first value based on the received plurality of gain values; and otherwise the gain value is set to a second value based on the received plurality of gain values. The suggested technology enables bringing gain values into agreement with peak positions in a bandwidth extended frequency region. | 03-26-2015 |