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6732069 |
Linear predictive analysis-by-synthesis encoding method and encoder
A linear predictive analysis-by-synthesis encoder includes a search algorithm block ( 50 ) and a vector quantizer ( 58 ) for vector quantizing optimal gains from a plurality of subframes in a...
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6732070 |
Wideband speech codec using a higher sampling rate in analysis and synthesis filtering than in excitation searching
A codec (coder and decoder) in which LP analysis and LP synthesis of a full wideband speech signal is performed, and, in an excitation search part of the coder (searching for a codeword in case of...
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6728669 |
Relative pulse position in celp vocoding
An apparatus and method for vocoding an input signal comprising a linear predictive filter for generating a filtered signal with a first signal pulse and a second signal pulse in response to...
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6711538 |
Information processing apparatus and method, and recording medium
In order to improve the accuracy of an excitation source for a band-spreading apparatus and to generate a wide-band signal having no gaps, an α band-widening section generates a prediction...
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6711537 |
Comfort noise generation for open discontinuous transmission systems
A Comfort Noise Generation (CNG) system is provided for use in open systems where there is no predefined protocol for transmission of Silence Insertion Descriptor (SID) information from transmitter...
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6704705 |
Perceptual audio coding
A method and apparatus for perceptual audio coding. The method and apparatus provide high-quality sound for coding rates down to and below 1 bit/sample for a wide variety of input signals including...
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6704701 |
Bi-directional pitch enhancement in speech coding systems
A bi-directional pitch enhancement system for speech coding systems. As speech data applications continue to operate in areas having intrinsic bandwidth limitations, the perceptual quality of...
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6694293 |
Speech coding system with a music classifier
The invention provides a speech coding system with a music classifier. An encoder is disposed to receive an input signal and provides a bitstream based upon a speech coding of a portion of the...
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6694010 |
Recognition of a single frequency tone
A fast-converging, computationally simple, method for recognizing a single frequency tone or a sinusoid in a signal without prior knowledge of the tone frequency. The method employs a second order...
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6694292 |
Apparatus for encoding and apparatus for decoding speech and musical signals
A speech and musical signal codec employing a band splitting technique encodes sound source signals of each of a plurality of bands using a small number of bits. The codec includes a second pulse...
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6691082 |
Method and system for sub-band hybrid coding
A system and method are provided for processing audio and speech signals using a pitch and voicing dependent spectral estimation algorithm (voicing algorithm) to accurately represent voiced speech,...
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6691092 |
Voicing measure as an estimate of signal periodicity for a frequency domain interpolative speech codec system
A system determines a voicing measure as a measure of the degree of signal periodicity and uses the determined voicing measure to quantize the spectral magnitude of the slowly evolving waveform...
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6691083 |
Wideband speech synthesis from a narrowband speech signal
Wideband speech is synthesized from a bandlimited speech signal, for example from speech which has been transmitted via the public switched telephone network. Due to the nature of the vocal tract,...
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6687667 |
Method for quantizing speech coder parameters
A method for encoding speech at a low bit rate. The method assembles parameters on N consecutive frames to form a super-frame. A vector quantization of transition frequencies of a voicing during...
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6687672 |
Methods and apparatus for blind channel estimation based upon speech correlation structure
Methods and apparatus for blind channel estimation of a speech signal corrupted by a communication channel are provided. One method includes converting a noisy speech signal into either a cepstral...
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6687668 |
Method for improvement of G.723.1 processing time and speech quality and for reduction of bit rate in CELP vocoder and CELP vococer using the same
A method of searching an MP-MLQ fixed codebook through bit predetermination includes the steps of generating a target vector with amplitude, reducing time to search an optimal pulse array through...
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6681209 |
Method and an apparatus for sampling-rate conversion of audio signals
Generally, performing sampling-rate conversion from a higher sampling frequency fs1 to a lower sampling frequency fs 2 results in aliasing. It is known to use a low-pass filter, known as...
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6678654 |
TDVC-to-MELP transcoder
The system and method of the present invention comprises a compressed domain universal transcoder that transcodes a bit stream representing frames of data encoded according to a first compression...
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6678653 |
Apparatus and method for coding audio data at high speed using precision information
An audio signal is converted from time domain into frequency conversion signal, and is coded at high speed. In order that the frequency information decoded by using the quantizing data may not be...
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6678649 |
Method and apparatus for subsampling phase spectrum information
Method and apparatus for subsampling phase spectrum information by analyzing and reconstructing a prototype of a frame. The prototype is analyzed by correlating phase parameters generated from the...
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6678647 |
Perceptual coding of audio signals using cascaded filterbanks for performing irrelevancy reduction and redundancy reduction with different spectral/temporal resolution
A perceptual audio coder is disclosed for encoding audio signals, such as speech or music, with different spectral and temporal resolutions for the redundancy reduction and irrelevancy reduction...
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6678651 |
Short-term enhancement in CELP speech coding
A speech-coding device includes a fixed codebook, an adaptive codebook, a short-term enhancement circuit, and a summing circuit. The short-term enhancement circuit connects an output of the fixed...
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6675144 |
Audio coding systems and methods
An audio signal is decomposed into lower and upper sub-band and at least the noise component of the sub-band is encoded. At the decoder the audio signal is synthesised by a decoding means which...
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6665638 |
Adaptive short-term post-filters for speech coders
Methods and systems for filtering synthesized or reconstructed speech are implemented. A filter based on a set of linear predictive coding (LPC) coefficients is constructed by transforming the LPC...
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6662153 |
Speech coding system and method using time-separated coding algorithm
A time-separated speech coder that codes a transitional signal of voiced/unvoiced sound through harmonic speech coding, the coder including a transitional excitation signal analyzer/synthesizer for...
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6662154 |
Method and system for information signal coding using combinatorial and huffman codes
The invention provides a method of coding an information signal. An information signal is represented by a sequence of pulses. A plurality of pulse parameters are determined based on the sequence...
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6661357 |
System for sampling rate conversion in digital audio applications
A method for upsampling a digital audio signal is described. The method includes receiving a first digital audio signal including samples and having a first sampling rate. The method also includes...
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6658112 |
Voice decoder and method for detecting channel errors using spectral energy evolution
A voice decoder detects channel errors and loss of cryptographic synchronization using the change in spectral energy between sequential frames. The change in energy between frames is determined...
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6658383 |
Method for coding speech and music signals
The present invention provides a transform coding method efficient for music signals that is suitable for use in a hybrid codec, whereby a common Linear Predictive (LP) synthesis filter is employed...
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6654718 |
Speech encoding method and apparatus, input signal discriminating method, speech decoding method and apparatus and program furnishing medium
In a speech codec, the total number of transmitted bits is reduced to decrease the average amount of bit transmission by imparting a relatively large number of bits to the voiced speech having a...
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6654716 |
Perceptually improved enhancement of encoded acoustic signals
The invention relates to encoding of broadband and narrowband acoustic source signals (x) such that the perceived sound quality of corresponding reconstructed signals is improved in comparison to...
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6650762 |
Types-based, lossy data embedding
A new approach to data embedding within ITU G.722 and ITU G.711 based upon the method of types and universal classification is disclosed. A secondary data sequence is embedded in the original...
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6640209 |
Closed-loop multimode mixed-domain linear prediction (MDLP) speech coder
A closed-loop, multimode, mixed-domain linear prediction (MDLP) speech coder includes a high-rate, time-domain coding mode, a low-rate, frequency-domain coding mode, and a closed-loop...
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6636829 |
Speech communication system and method for handling lost frames
An exemplary decoder comprises a receiver that receives parameters of a speech signal on a frame-by-frame basis, a control logic for decoding parameters and for resynthesizing the speech signal,...
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6633841 |
Voice activity detection speech coding to accommodate music signals
An extended signal coding system that accommodates substantially music-like signals within a signal while maintaining a high perceptual quality in a reproduced signal during discontinued...
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RE38269 |
Enhancement of speech coding in background noise for low-rate speech coder
A speech coding system employs measurements of robust features of speech frames whose distribution are not strongly affected by noise/levels to make voicing decisions for input speech occurring in...
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6631347 |
Vector quantization and decoding apparatus for speech signals and method thereof
A vector quantizing apparatus, a decoding apparatus, a vector quantization method, and a decoding method are provided. Upon encoding of a speech signal by the vector quantization apparatus and...
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6625574 |
Method and apparatus for sub-band coding and decoding
An input digital audio signal is divided into sub-band signals in respective sub-bands. Scale factors of the respective sub-bands are determined on the basis of the sub-band signals for every...
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6622117 |
EM algorithm for convolutive independent component analysis (CICA)
In connection with blind source separation, proposed herein, inter alia, are: expectation-maximization equations to iteratively estimate unmixing filters and source density parameters in the...
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6611798 |
Perceptually improved encoding of acoustic signals
Encoding an acoustic source signal such that a signal {circumflex over (z)} reconstructed from the encoded information has a perceptually high sound quality. The acoustic source signal is encoded...
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6608877 |
Reduced complexity signal transmission system
In a CELP coder a comparison between a target signal and a plurality of synthetic signals is made. The synthetic signal is derived by filtering a plurality of excitation sequences by a synthesis...
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6606591 |
Speech coding employing hybrid linear prediction coding
A speech coding system that employs hybrid linear prediction coding during extraction of linear prediction coefficients within ITU-Recommendation speech coding standards. The present invention is...
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6606592 |
Variable dimension spectral magnitude quantization apparatus and method using predictive and mel-scale binary vector
A variable dimension spectral magnitude quantization apparatus and method using a predictive and mel scale binary vector is provided. The apparatus according to linear prediction spectral envelope...
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6603832 |
CELP coding with two-stage search over displaced segments of a one-dimensional codebook
In a CELP coder a comparison between a target signal and a plurality of synthetic signals is made. The synthetic signal is derived by filtering a plurality of excitation sequences from a one...
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6601074 |
Episode identification
A method, system, signal and software which maintains an electronic program guide (EPG) that includes episode identifiers associated with program information. The method includes keeping a database...
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6590972 |
DTMF detection based on LPC coefficients
A system and method for DTMF tone detection receives an input signal. The input signal includes a DTMF tone. The DTMF tone has a first frequency and a second frequency. An initial first frequency...
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6584441 |
Adaptive postfilter
The invention relates to the coding of speech at a variable bit rate, whereby the bit rates can vary from frame to frame, and more specifically to the methods and filters used for improving the...
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6581030 |
Target signal reference shifting employed in code-excited linear prediction speech coding
A speech coding system that employs target signal reference shifting in code-excited linear prediction speech coding. The speech coding system performs modification of a target signal that is used...
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6564183 |
Speech coding including soft adaptability feature
A speech encoding/decoding apparatus. A speech encoding apparatus has a coding portion for receiving input information related to an uncoded signal representative of an original speech signal, the...
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6564182 |
Look-ahead pitch determination
An encoding system is presented for coding and processing an input signal on a frame-by-frame basis. The encoding system processes each frame in two subframes of a first half and a second half. In...
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