Patents by Inventor Stefan DÖHLA

Stefan DÖHLA has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 10176817
    Abstract: The invention provides an audio encoder including a combination of a linear predictive coding filter having a plurality of linear predictive coding coefficients and a time-frequency converter, wherein the combination is configured to filter and to convert a frame of the audio signal into a frequency domain in order to output a spectrum based on the frame and on the linear predictive coding coefficients; a low frequency emphasizer configured to calculate a processed spectrum based on the spectrum, wherein spectral lines of the processed spectrum representing a lower frequency than a reference spectral line are emphasized; and a control device configured to control the calculation of the processed spectrum by the low frequency emphasizer depending on the linear predictive coding coefficients of the linear predictive coding filter.
    Type: Grant
    Filed: July 28, 2015
    Date of Patent: January 8, 2019
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Stefan Doehla, Bernhard Grill, Christian Helmrich, Nikolaus Rettelbach
  • Patent number: 10147432
    Abstract: The invention provides a decoder being configured for processing an encoded audio bitstream, wherein the decoder includes: a bitstream decoder configured to derive a decoded audio signal from the bitstream, wherein the decoded audio signal includes at least one decoded frame; a noise estimation device configured to produce a noise estimation signal containing an estimation of the level and/or the spectral shape of a noise in the decoded audio signal; a comfort noise generating device configured to derive a comfort noise signal from the noise estimation signal; and a combiner configured to combine the decoded frame of the decoded audio signal and the comfort noise signal in order to obtain an audio output signal.
    Type: Grant
    Filed: June 19, 2015
    Date of Patent: December 4, 2018
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Guillaume Fuchs, Anthony Lombard, Emmanuel Ravelli, Stefan Doehla, Jeremie Lecomte, Martin Dietz
  • Publication number: 20180342253
    Abstract: The invention provides a decoder being configured for processing an encoded audio bitstream, wherein the decoder includes: a bitstream decoder configured to derive a decoded audio signal from the bitstream, wherein the decoded audio signal includes at least one decoded frame; a noise estimation device configured to produce a noise estimation signal containing an estimation of the level and/or the spectral shape of a noise in the decoded audio signal; a comfort noise generating device configured to derive a comfort noise signal from the noise estimation signal; and a combiner configured to combine the decoded frame of the decoded audio signal and the comfort noise signal in order to obtain an audio output signal.
    Type: Application
    Filed: August 2, 2018
    Publication date: November 29, 2018
    Inventors: Guillaume FUCHS, Anthony LOMBARD, Emmanuel RAVELLI, Stefan DOEHLA, Jérémie LECOMTE, Martin DIETZ
  • Publication number: 20180342252
    Abstract: An apparatus for encoding a multi-channel signal including at least two channels includes a time-spectral converter for converting sequences of blocks of sampling values of the at least two channels into a frequency domain representation having sequences of blocks of spectral values for the at least two channels; a multi-channel processor for applying a joint multi-channel processing to the sequences of blocks of spectral values to obtain at least one result sequence of blocks of spectral values including information related to the at least two channels; a spectral-time converter for converting the result sequence of blocks of spectral values into a time domain representation including an output sequence of blocks of sampling values; and a core encoder for encoding the output sequence of blocks of sampling values to obtain an encoded multi-channel signal.
    Type: Application
    Filed: July 13, 2018
    Publication date: November 29, 2018
    Inventors: Guillaume FUCHS, Emmanuel RAVELLI, Markus MULTRUS, Markus SCHNELL, Stefan DOEHLA, Martin DIETZ, Goran MARKOVIC, Eleni FOTOPOULOU, Stefan BAYER, Wolfgang JAEGERS
  • Publication number: 20180330740
    Abstract: An apparatus for encoding a first channel and a second channel of an audio input signal including two or more channels to obtain an encoded audio signal according to an embodiment includes a normalizer configured to determine a normalization value for the audio input signal depending on the first channel of the audio input signal and depending on the second channel of the audio input signal. Moreover, the apparatus includes an encoding unit configured to generate a processed audio signal having a first channel and a second channel. The encoding unit is configured to encode the processed audio signal to obtain the encoded audio signal.
    Type: Application
    Filed: July 20, 2018
    Publication date: November 15, 2018
    Inventors: Emmanuel Ravelli, Markus Schnell, Stefan Doehla, Wolfgang Jaegers, Martin Dietz, Christian Helmrich, Goran Markovic, Eleni Fotopoulou, Markus Multrus, Stefan Bayer, Guillaume Fuchs, Juergen Herre
  • Publication number: 20180322884
    Abstract: An apparatus for estimating an inter-channel time difference between a first channel signal and a second channel signal, includes: a calculator for calculating a cross-correlation spectrum for a time block from the first channel signal in the time block and the second channel signal in the time block; a spectral characteristic estimator for estimating a characteristic of a spectrum of the first channel signal or the second channel signal for the time block; a smoothing filter for smoothing the cross-correlation spectrum over time using the spectral characteristic to obtain a smoothed cross-correlation spectrum; and a processor for processing the smoothed cross-correlation spectrum to obtain the inter-channel time difference.
    Type: Application
    Filed: July 13, 2018
    Publication date: November 8, 2018
    Inventors: Stefan BAYER, Eleni FOTOPOULOU, Markus MULTRUS, Guillaume FUCHS, Emmanuel RAVELLI, Markus SCHNELL, Stefan DOEHLA, Wolfgang JAEGERS, Martin DIETZ, Goran MARKOVIC
  • Publication number: 20180322883
    Abstract: The apparatus for encoding a multi-channel signal having at least two channels, includes: a parameter determiner for determining a broadband alignment parameter and a plurality of narrowband alignment parameters from the multichannel signal; a signal aligner for aligning the at least two channels using the broadband alignment parameter and the plurality of narrowband alignment parameters to obtain aligned channels; a signal processor for calculating a mid-signal and a side signal using the aligned channels; a signal encoder for encoding the mid-signal to obtain an encoded mid-signal and for encoding the side signal to obtain an encoded side signal; and an output interface for generating an encoded multi-channel signal including the encoded mid-signal, the encoded side signal, information on the broadband alignment parameter and information on the plurality of narrowband alignment parameters.
    Type: Application
    Filed: July 12, 2018
    Publication date: November 8, 2018
    Inventors: Stefan BAYER, Eleni FOTOPOULOU, Markus MULTRUS, Guillaume FUCHS, Emmanuel RAVELLI, Markus SCHNELL, Stefan DOEHLA, Wolfgang JAEGERS, Martin DIETZ, Goran MARKOVIC
  • Patent number: 10115401
    Abstract: A coding efficiency of coding spectral coefficients of a spectrum of an audio signal is increased by en/decoding a currently to be en/decoded spectral coefficient by entropy en/decoding and, in doing so, performing the entropy en/decoding depending, in a context-adaptive manner, on a previously en/decoded spectral coefficient, while adjusting a relative spectral distance between the previously en/decoded spectral coefficient and the currently en/decoded spectral coefficient depending on an information concerning a shape of the spectrum.
    Type: Grant
    Filed: January 2, 2018
    Date of Patent: October 30, 2018
    Inventors: Guillaume Fuchs, Matthias Neusinger, Markus Multrus, Stefan Doehla
  • Publication number: 20180293993
    Abstract: The invention provides an audio encoder including a combination of a linear predictive coding filter having a plurality of linear predictive coding coefficients and a time-frequency converter, wherein the combination is configured to filter and to convert a frame of the audio signal into a frequency domain in order to output a spectrum based on the frame and on the linear predictive coding coefficients; a low frequency emphasizer configured to calculate a processed spectrum based on the spectrum, wherein spectral lines of the processed spectrum representing a lower frequency than a reference spectral line are emphasized; and a control device configured to control the calculation of the processed spectrum by the low frequency emphasizer depending on the linear predictive coding coefficients of the linear predictive coding filter.
    Type: Application
    Filed: July 28, 2015
    Publication date: October 11, 2018
    Inventors: Stefan DOEHLA, Bernhard GRILL, Christian HELMRICH, Nikolaus RETTELBACH
  • Patent number: 10083706
    Abstract: The coding efficiency of an audio codec using a controllable—switchable or even adjustable—harmonic filter tool is improved by performing the harmonicity-dependent controlling of this tool using a temporal structure measure in addition to a measure of harmonicity in order to control the harmonic filter tool. In particular, the temporal structure of the audio signal is evaluated in a manner which depends on the pitch. This enables to achieve a situation-adapted control of the harmonic filter tool so that in situations where a control made solely based on the measure of harmonicity would decide against or reduce the usage of this tool, although using the harmonic filter tool would, in that situation, increase the coding efficiency, the harmonic filter tool is applied, while in other situations where the harmonic filter tool may be inefficient or even destructive, the control reduces the appliance of the harmonic filter tool appropriately.
    Type: Grant
    Filed: January 20, 2017
    Date of Patent: September 25, 2018
    Assignee: Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e. V.
    Inventors: Goran Markovic, Christian Helmrich, Emmanuel Ravelli, Manuel Jander, Stefan Doehla
  • Publication number: 20180240467
    Abstract: The invention provides an audio encoder including a combination of a linear predictive coding filter having a plurality of linear predictive coding coefficients and a time-frequency converter, wherein the combination is configured to filter and to convert a frame of the audio signal into a frequency domain in order to output a spectrum based on the frame and on the linear predictive coding coefficients; a low frequency emphasizer configured to calculate a processed spectrum based on the spectrum, wherein spectral lines of the processed spectrum representing a lower frequency than a reference spectral line are emphasized; and a control device configured to control the calculation of the processed spectrum by the low frequency emphasizer depending on the linear predictive coding coefficients of the linear predictive coding filter.
    Type: Application
    Filed: April 18, 2018
    Publication date: August 23, 2018
    Inventors: Stefan Doehla, Bernhard Grill, Christian Helmrich, Nikolaus Rettelbach
  • Publication number: 20180233155
    Abstract: A better compromise between a too high bitstream and decoding overhead on the one hand and flexibility of frame element positioning on the other hand is achieved by arranging that each of the sequence of frames of the bitstream has a sequence of N frame elements and, on the other hand, the bitstream has a configuration block having a field indicating the number of elements N and a type indication syntax portion indicating, for each element position of the sequence of N element positions, an element type out of a plurality of element types with, in the sequences of N frame elements of the frames, each frame element being of the element type indicated, by the type indication portion, for the respective element position at which the respective frame element is positioned within the sequence of N frame elements of the respective frame in the bitstream.
    Type: Application
    Filed: April 11, 2018
    Publication date: August 16, 2018
    Inventors: Max NEUENDORF, Markus MULTRUS, Stefan DOEHLA, Heiko PURNHAGEN, Frans DE BONT
  • Publication number: 20180197556
    Abstract: An audio decoder decodes a bit stream of encoded audio data, which bit stream represents a sequence of audio sample values and includes a plurality of frames, wherein each frame includes associated encoded audio sample values. The audio decoder includes a determiner configured to determine whether a frame of the encoded audio data is a special frame including encoded audio sample values associated with the special frame and additional information, wherein the additional information include encoded audio sample values of a number of frames preceding the special frame, wherein the encoded audio sample values of the preceding frames are encoded using the same codec configuration as the special frame, wherein the number of preceding frames is sufficient to initialize the decoder to be in a position to decode the audio sample values associated with the special frame if the special frame is the first frame upon start-up of the decoder.
    Type: Application
    Filed: March 9, 2018
    Publication date: July 12, 2018
    Inventors: Daniel FISCHER, Bernd CZELHAN, Max NEUENDORF, Nikolaus RETTELBACH, Ingo HOFMANN, Harald FUCHS, Stefan DOEHLA, Nikolaus FAERBER
  • Publication number: 20180197552
    Abstract: An apparatus for encoding a multi-channel signal having at least two channels, has: a time-spectral converter for converting sequences of blocks of sample values of the at least two channels into a frequency domain representation having sequences of blocks of spectral values for the at least two channels, wherein a block of sampling values has an associated input sampling rate, and a block of spectral values of the sequences of blocks of spectral values has spectral values up to a maximum input frequency being related to the input sampling rate; a multi-channel processor to obtain at least one result sequence of blocks of spectral values having information related to the at least two channels; a spectral domain resampler to obtain a resampled sequence of blocks of spectral values; a spectral-time converter for converting the resampled sequence of blocks of spectral values into a time domain representation; and a core encoder for encoding the output sequence of blocks of sampling values to obtain an encoded mu
    Type: Application
    Filed: November 22, 2017
    Publication date: July 12, 2018
    Inventors: Guillaume FUCHS, Emmanuel RAVELLI, Markus MULTRUS, Markus SCHNELL, Stefan DOEHLA, Martin DIETZ, Goran MARKOVIC, Eleni FOTOPOULOU, Stefan BAYER, Wolfgang JAEGERS
  • Publication number: 20180190302
    Abstract: A jitter buffer control for controlling a provision of a decoded audio content on the basis of an input audio content is configured to select a frame-based time scaling or a sample-based time scaling in a signal-adaptive manner. An audio decoder uses such a jitter buffer control.
    Type: Application
    Filed: March 2, 2018
    Publication date: July 5, 2018
    Inventors: Stefan REUSCHL, Stefan DOEHLA, Jérémie LECOMTE, Manuel JANDER
  • Patent number: 9997167
    Abstract: A jitter buffer control for controlling a provision of a decoded audio content on the basis of an input audio content is configured to select a frame-based time scaling or a sample-based time scaling in a signal-adaptive manner. An audio decoder uses such a jitter buffer control.
    Type: Grant
    Filed: December 18, 2015
    Date of Patent: June 12, 2018
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Stefan Reuschl, Stefan Doehla, Jeremie Lecomte, Manuel Jander
  • Patent number: 9986287
    Abstract: A transport stream provider for providing a plurality of transport stream packets describing digital media information is configured to provide a transport stream packet of a first packet type including a program association table and key information for decrypting encrypted media information. The program association table contains an association between a program No. and a packet type identifier of a further transport stream packet of a second packet type. The transport stream provider is configured to provide a transport stream packet of the second packet type in such a manner that the transport stream packet of the second packet type contains a reference to packet type identifiers of transport stream payload data packets which describe contents of different content types of the digital media information.
    Type: Grant
    Filed: June 24, 2014
    Date of Patent: May 29, 2018
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Birgit Bartel-Kurz, Stefan Doehla, Markus Prosch
  • Patent number: 9972331
    Abstract: A better compromise between a too high bitstream and decoding overhead on the one hand and flexibility of frame element positioning on the other hand is achieved by arranging that each of the sequence of frames of the bitstream has a sequence of N frame elements and, on the other hand, the bitstream has a configuration block having a field indicating the number of elements N and a type indication syntax portion indicating, for each element position of the sequence of N element positions, an element type out of a plurality of element types with, in the sequences of N frame elements of the frames, each frame element being of the element type indicated, by the type indication portion, for the respective element position at which the respective frame element is positioned within the sequence of N frame elements of the respective frame in the bitstream.
    Type: Grant
    Filed: June 5, 2017
    Date of Patent: May 15, 2018
    Assignees: FRAUNHOFER-GESELLSCHAFT ZUR FOERDERUNG DER ANGEWANDTEN FORSCHUNG E.V., DOLBY INTERNATIONAL AB, KONINKLIJKE PHILIPS N.V.
    Inventors: Max Neuendorf, Markus Multrus, Stefan Doehla, Heiko Purnhagen, Frans De Bont
  • Publication number: 20180122387
    Abstract: A coding efficiency of coding spectral coefficients of a spectrum of an audio signal is increased by en/decoding a currently to be en/decoded spectral coefficient by entropy en/decoding and, in doing so, performing the entropy en/decoding depending, in a context-adaptive manner, on a previously en/decoded spectral coefficient, while adjusting a relative spectral distance between the previously en/decoded spectral coefficient and the currently en/decoded spectral coefficient depending on an information concerning a shape of the spectrum.
    Type: Application
    Filed: January 2, 2018
    Publication date: May 3, 2018
    Inventors: Guillaume FUCHS, Matthias NEUSINGER, Markus MULTRUS, Stefan DOEHLA
  • Patent number: 9928845
    Abstract: An audio decoder decodes a bit stream of encoded audio data, which bit stream represents a sequence of audio sample values and includes a plurality of frames, wherein each frame includes associated encoded audio sample values. The audio decoder includes a determiner configured to determine whether a frame of the encoded audio data is a special frame including encoded audio sample values associated with the special frame and additional information, wherein the additional information include encoded audio sample values of a number of frames preceding the special frame, wherein the encoded audio sample values of the preceding frames are encoded using the same codec configuration as the special frame, wherein the number of preceding frames is sufficient to initialize the decoder to be in a position to decode the audio sample values associated with the special frame if the special frame is the first frame upon start-up of the decoder.
    Type: Grant
    Filed: April 18, 2016
    Date of Patent: March 27, 2018
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Daniel Fischer, Bernd Czelhan, Max Neuendorf, Nikolaus Rettelbach, Ingo Hofmann, Harald Fuchs, Stefan Doehla, Nikolaus Faerber