Texas Instruments Corporation

Jacek Piotr Stachurski

Lorin Paul Netsch

Alan V McCree

Ali Erdem Ertan

A method of encoding samples in a digital signal is provided that includes receiving a frame of N samples of the digital signal, determining L possible distinct data values in the N samples, determining a reference data value in the L possible distinct data values and a coding order of L−1 remaining possible distinct data values, wherein each of the L−1 remaining possible distinct data values is mapped to a position in the coding order, decomposing the N samples into L−1 coding vectors based on the coding order, wherein each coding vector identifies the locations of one of the L−1 remaining possible distinct data values in the N samples, and encoding the L−1 coding vectors.

Method and system for lossless value-location encoding

A method for sound source localization in a digital system having at least two audio capture devices is provided that includes receiving audio signals from the two audio capture devices, computing a signal-to-noise ratio (SNR) for each frequency band of a plurality of frequency bands in a processing frame of the audio signals, determining a frequency band weight for each frequency band of the plurality of frequency bands based on the SNR computed for the frequency band, computing an estimated time delay of arrival (TDOA) of sound for the processing frame using the frequency band weights, and converting the estimated TDOA to an angle representing sound direction.

Robust estimation of sound source localization

A method of encoding samples in a digital signal is provided that includes receiving a frame of N samples of the digital signal, determining L possible distinct data values in the N samples, determining a reference data value in the L possible distinct data values and a coding order of L&#x2212;1 remaining possible distinct data values, wherein each of the L&#x2212;1 remaining possible distinct data values is mapped to a position in the coding order, decomposing the N samples into L&#x2212;1 coding vectors based on the coding order, wherein each coding vector identifies the locations of one of the L&#x2212;1 remaining possible distinct data values in the N samples, and encoding the L&#x2212;1 coding vectors.

A method of encoding samples in a digital signal is provided that includes receiving a plurality of samples of the digital signal, and encoding the plurality of samples, wherein an output number of bits is adapted for coding efficiency when a value in a range of possible distinct data values of the plurality of samples is not found in the plurality of samples.

Adaptive encoding of a digital signal with one or more missing values

A layered code-excited linear prediction (CELP) encoder, an Adaptive Multirate Wideband (AMR-WB) encoder and methods of CELP encoding and decoding. In one embodiment, the encoder includes: (1) a core layer subencoder and (2) at least one enhancement layer subencoder, at least one of the core layer subencoder and the enhancement layer subencoder having first and second adaptive codebooks and configured to retrieve a pitch lag estimate from the second adaptive codebook and perform a closed-loop search of the first adaptive codebook based on the pitch lag estimate.

Method and apparatus for layered code-excited linear prediction speech utilizing linear prediction excitation corresponding to optimal gains

Methods, encoders, and digital systems are provided for predictive encoding of speech parameters in which an input frame is encoded by quantizing a parameter vector of the input frame with a strongly-predictive codebook and a weakly-predictive codebook to obtain a strongly-predictive distortion and a weakly-predictive distortion, adjusting a correlation indicator based on a relative correlation of the input frame to a previous frame, wherein the correlation indicator is indicative of the strength of the correlation of previously encoded frames, and encoding the input frame with the weakly-predictive codebook unless the correlation indicator has reached a correlation threshold.

Method and system for speech compression

Layered (embedded) code-excited linear prediction (CELP) speech encoders/decoders with adaptive plus algebraic codebooks applied in each layer with fixed codebook pulses of one layer used in higher layers. Pulse weightings emphasize lower layer pulses relative to the higher layer pulses.

Layered CELP system and method

Hybrid linear predictive speech coding system with phase alignment predictive quantization zero phase alignment of speech prior to waveform coding aligns synthesized speech frames of a waveform coder with frames synthesized with a parametric coder. Inter-frame interpolation of LP coefficients suppresses artifacts in resultant synthesized speech frames.

Hybrid speech coding and system

Linear predictive system with classification of LP residual Fourier coefficients into two or more overlapping classes, and each class has its own vector quantization codebook(s). The use of strong and weak predictors minimizes codebook size by only quantizing the difference between Fourier coefficients of a frame and the Fourier coefficients predicted from a prior frame. The choice of using either a strong or weak predictor adapts to the prior choice of predictor so that a strong predictor following a weak predictor is changed to a weak predictor to insure attenuation of error propagation as arise from frame erasures.

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Dallas, TX, United States of America

Jacek Piotr Stachurski