Patent application number | Description | Published |
20090299755 | Method for Post-Processing a Signal in an Audio Decoder - A method of post-processing in an audio decoder a signal reconstructed by time and frequency shaping ( | 12-03-2009 |
20090326931 | HIERARCHICAL ENCODING/DECODING DEVICE - A system for coding a hierarchical audio signal, comprising, at least, a core layer using parametric coding by analysis by synthesis in a first frequency band, a band extension layer for widening said first frequency band into a second frequency band, or wideband. The system also comprises a wideband audio coding quality enhancement layer based on transform coding using a spectral parameter obtained from said band extension layer. Application to transmitting speech and/or audio signals over packet networks. | 12-31-2009 |
20100121646 | CODING/DECODING OF DIGITAL AUDIO SIGNALS - The invention relates to the coding/decoding of a signal into several sub-bands, in which at least a first and a second sub-bands which are adjacent are transform coded ( | 05-13-2010 |
20100145712 | CODING OF DIGITAL AUDIO SIGNALS - The invention concerns an encoder for an input audio signal (S(z)) comprising a combination module combining the input audio signal with an intermediate counter-reaction signal forming a modified input signal and a quantification module scalable for the rate ( | 06-10-2010 |
20100191538 | HIERARCHICAL CODING OF DIGITAL AUDIO SIGNALS - The invention relates to a method for scalar quantization-based coding of the samples of a digital audio signal (S), the samples being coded over a pre-determined number of bits in order to obtain a binary frame of quantization indices (I | 07-29-2010 |
20100241427 | LIMITATION OF DISTORTION INTRODUCED BY A POST-PROCESSING STEP DURING DIGITAL SIGNAL DECODING - The invention relates to the processing of a digital signal originating from a decoder and a noise reduction post-processing step, including, in particular, limitation of distortion introduced by the post-processing step in order to deliver a corrected output signal (S | 09-23-2010 |
20100306625 | TRANSMISSION ERROR DISSIMULATION IN A DIGITAL SIGNAL WITH COMPLEXITY DISTRIBUTION - The present invention relates to a method of transmission error concealment in a digital signal split up into a plurality of successive frames associated with different time intervals in which, on reception, the signal might comprise erased frames and valid frames and in order to replace at least the first erased frame (N) after a valid frame, at least two steps are performed, a first step (E | 12-02-2010 |
20100306629 | PROCESSING OF BIT ERRORS IN A DIGITAL AUDIO BIT FRAME - The invention relates to a method of processing bit errors in a bit frame emanating from a digital audio coder, comprising a step of receiving a current bit frame liable to comprise bit errors. According to the invention, the bit frame comprises sensitive bits to be protected which are catalogued in at least one category according to the type of parameter that they code and the method furthermore comprises the steps of receiving protection bits, of reading the sensitive bits received in the current bit frame, the number of sensitive bits being lower than the number of bits of the bit frame, of detecting bit errors as a function of said protection bits received and of said sensitive bits received and in the event of detecting at least one erroneous bit in said bit frame, of modifying the current bit frame before decoding, as a function of the category in which the erroneous bit is catalogued. The invention also pertains to a device implementing the method according to the invention as well as to a decoder and a coding/decoding system comprising such a device. | 12-02-2010 |
20100318349 | SYNTHESIS OF LOST BLOCKS OF A DIGITAL AUDIO SIGNAL, WITH PITCH PERIOD CORRECTION - The present invention relates to signal modification before pitch period repetition for the synthesis of blocks lost on decoding digital audio signals. The effects of repetition of transitories, such as the plosives of a speech signal, are avoided by comparing the samples of a pitch period with those of the previous pitch period. The signal is modified preferentially by taking the minimum between a current sample (e( | 12-16-2010 |
20110116542 | SYMBOL PLANE ENCODING/DECODING WITH DYNAMIC CALCULATION OF PROBABILITY TABLES - The invention relates to an arithmetic encoding by bit planes (MSB, . . . , LSB), that comprises using tables of probability to have a 0 or 1 bit for encoding each bit plane. According to an embodiment of the invention, the probability tables are calculated dynamically for each signal frame based on a probability density model (Mod) corresponding to the distribution (H) of the signal (X) on each frame. | 05-19-2011 |
20120207311 | OPTIMIZED LOW-BIT RATE PARAMETRIC CODING/DECODING - A parametric coding method and apparatus are provided for coding a multichannel digital audio signal. The method includes a coding step for coding a signal from a channel reduction matrixing of the multichannel signal. The coding method also includes: obtaining, for each frame of predetermined length, spatial information parameters of the multichannel signal; dividing the spatial information parameters into a plurality of blocks of parameters; selecting a block of parameters as a function of the index of the current frame; and coding the block of parameters selected for the current frame. | 08-16-2012 |
20120265542 | OPTIMIZED PARAMETRIC STEREO DECODING - A method and decoder are provided for parametrically decoding a stereo digital audio signal. The method includes synthesizing the stereo signal, per frequency sub-band, on the basis of a decoded mono signal ({circumflex over (M)}[j]), arising from a downmix of the stereo signal and from spatial information parameters of the stereo signal, in such a way that the signals obtained have the following form: | 10-18-2012 |
20130204630 | Controlling a Noise-Shaping Feedback Loop in a Digital Audio Signal Encoder - A method and apparatus are provided for controlling the shaping of encoding noise during the ADPCM encoding of a digital audio input signal. The noise-shaping is carried out through the use of feedback that comprises filtering noise. The method includes the following steps: obtaining a parameter for indicating a high spectral dynamic range of the signal, the parameter indicating a risk of instability of the feedback; detecting a risk of instability by comparing the indication parameter to at least one predetermined threshold; limiting the feedback in the event that a risk of instability is detected; and gradually reactivating the feedback over a predetermined number of frames subsequent to the current frame for which the feedback is limited. Also provided is an encoder with feedback, including a control module implementing the control method as described. | 08-08-2013 |
20130262130 | STEREO PARAMETRIC CODING/DECODING FOR CHANNELS IN PHASE OPPOSITION - A method and apparatus for the parametric encoding of a stereo digital-audio signal. The method includes encoding a mono signal produced by downmixing applied to the stereo signal and encoding spatialisation information of the stereo signal. Downmixing includes determining, for a predetermined set of frequency sub-bands, a phase difference between two stereo channels; obtaining an intermediate channel by rotating a first predetermined channel of the stereo signal through an angle obtained by reducing the phase difference; determining the phase of the mono signal from the phase of the signal that is the sum of the intermediate channel and the second stereo signal, and from a phase difference between, on the one hand, the signal that is the sum of the intermediate channel and the second channel and, on the other hand, the second channel of the stereo signal. Also provided are a decoding method, an encoder and a decoder. | 10-03-2013 |
20130268268 | ENCODING OF AN IMPROVEMENT STAGE IN A HIERARCHICAL ENCODER - A method and coding device are provided for coding a digital audio input signal in a hierarchical coder, which includes a core coding stage with B bits and at least one current improvement coding stage k, delivering quantization indices which are concatenated to form the indices of a preceding embedded coder. The method includes: obtaining possible quantization values for the current improvement stage k by determining absolute reconstruction levels of just the current stage k on the basis of the indices of the preceding embedded coder; and quantizing the input signal of the hierarchical coder having undergone or not a perceptual weighting processing, on the basis of the possible quantization values so as to form a scalar quantization index for the stage k and a quantized signal corresponding to one of the possible quantization values. | 10-10-2013 |
20130289981 | LOW-DELAY SOUND-ENCODING ALTERNATING BETWEEN PREDICTIVE ENCODING AND TRANSFORM ENCODING - An encoder and a method for encoding a digital signal are provided. The method includes encoding a preceding frame of samples of the digital signal according to a predictive encoding process, and encoding a current frame of samples of the digital signal according to a transform encoding process. The method is implemented such that a first portion of the current frame is also encoded by predictive encoding that is limited relative to the predictive encoding of the preceding frame by reusing at least one parameter of the predictive encoding of the preceding frame and only encoding the parameters of said first portion of the current frame that are not reused. A decoder and a decoding method are also provided, which correspond to the described encoding method. | 10-31-2013 |