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51. 发明专利

AU2003297342A1 SUB-SAMPLED EXCITATION WAVEFORM CODEBOOKS 未知
公开(公告)号：AU2003297342A1
公开(公告)日：2004-07-14
申请号：AU2003297342
申请日：2003-12-17
申请人： QUALCOMM INC
发明人： KANDHADAI ANANTHAPADMANABHAN A , MANJUNATH SHARATH , EL-MALEH KHALED
IPC分类号： G10L19/00 , G10L19/12 , G10L19/14
摘要： Methods and apparatus are presented for reducing the number of bits needed to represent an excitation waveform. An acoustic signal in an analysis frame is analyzed to determine whether it is a band-limited signal. A sub-sampled sparse codebook is used to generate the excitation waveform if the acoustic signal is a band-limited signal. The sub-sampled sparse codebook is generated by decimating permissible pulse locations from the codebook track in accordance with the frequency characteristic of the acoustic signal.

52. 发明专利

BR0012540A 未知
公开(公告)号：BR0012540A
公开(公告)日：2004-06-29
申请号：BR0012540
申请日：2000-07-19
申请人： QUALCOMM INC
发明人： ANANTHAPADMANABHAN ARASANIPALA , MANJUNATH SHARATH
IPC分类号： G10L19/06 , G10L19/00 , G10L19/04 , H03M7/30
摘要： A method and apparatus for interleaving line spectral information quantization methods in a speech coder includes quantizing line spectral information with two vector quantization techniques, the first technique being a non-moving-average prediction-based technique, and the second technique being a moving-average prediction-based technique. A line spectral information vector is vector quantized with the first technique. Equivalent moving average codevectors for the first technique are computed. A memory of a moving average codebook of codevectors is updated with the equivalent moving average codevectors for a predefined number of frames that were previously processed by the speech coder. A target quantization vector for the second technique is calculated based on the updated moving average codebook memory. The target quantization vector is vector quantized with the second technique to generate a quantized target codevector. The memory of the moving average codebook is updated with the quantized target codevector. Quantized line spectral information vectors are derived from the quantized target codevector.

53. 发明专利

ES2176478T3 未知
公开(公告)号：ES2176478T3
公开(公告)日：2002-12-01
申请号：ES96926869
申请日：1996-08-01
申请人： QUALCOMM INC
发明人： GARDNER WILLIAM R , MANJUNATH SHARATH , MONTA PETER
IPC分类号： G10L19/02 , G10L19/00 , G10L19/04 , G10L19/06 , H03M7/30 , H03M7/36 , H04B14/04
摘要： A novel and improved method and apparatus for encoding line predictive coding (LPC) data in a speech compression system using line spectral square root values is disclosed. A novel and computationally efficient procedure for determining the set of quantization sensitivities for the line spectral square root values is disclosed, which results in a computationally efficient error measure for use in vector quantization of the line spectral square root values. A novel method of weighting the quantization error is disclosed, which accumulates the quantization error in each line spectral square root value and weights that error by the sensitivity of that line spectral square root value.\!

54. 发明专利

PT842509E 未知
公开(公告)号：PT842509E
公开(公告)日：2002-10-31
申请号：PT96926869
申请日：1996-08-01
申请人： QUALCOMM INC
发明人： GARDNER WILLIAM R , MANJUNATH SHARATH , MONTA PETER
IPC分类号： G10L19/02 , G10L19/00 , G10L19/04 , G10L19/06 , H03M7/30 , H03M7/36 , H04B14/04
摘要： A novel and improved method and apparatus for encoding line predictive coding (LPC) data in a speech compression system using line spectral square root values is disclosed. A novel and computationally efficient procedure for determining the set of quantization sensitivities for the line spectral square root values is disclosed, which results in a computationally efficient error measure for use in vector quantization of the line spectral square root values. A novel method of weighting the quantization error is disclosed, which accumulates the quantization error in each line spectral square root value and weights that error by the sensitivity of that line spectral square root value.\!

55. 发明专利

HK1042370A1 Low bit-rate coding of unvoiced segments of speech 未知
公开(公告)号：HK1042370A1
公开(公告)日：2002-08-09
申请号：HK02104019
申请日：2002-05-30
申请人： QUALCOMM INC
发明人： DAS AMITAVA , MANJUNATH SHARATH
IPC分类号： G10L19/00 , G10L19/04 , G10L19/08 , G10L19/14 , G10L25/93 , H03M7/30 , G10L
摘要： A low-bit-rate coding technique for unvoiced segments of speech includes the steps of extracting high-time-resolution energy coefficients from a frame of speech, quantizing the energy coefficients, generating a high-time-resolution energy envelope from the quantized energy coefficients, and reconstituting a residue signal by shaping a randomly generated noise vector with quantized values of the energy envelope. The energy envelope may be generated with a linear interpolation technique. A post-processing measure may be obtained and compared with a predefined threshold to determine whether the coding algorithm is performing adequately.

56. 发明专利

BR0012539A 未知
公开(公告)号：BR0012539A
公开(公告)日：2002-07-23
申请号：BR0012539
申请日：2000-07-19
申请人： QUALCOMM INC
发明人： MANJUNATH SHARATH , DEJACO ANDREW P
IPC分类号： G10L19/00 , G10L19/04 , H04B7/26
摘要： A method and apparatus for providing feedback from the decoder to the encoder to improve performance in a predictive speech coder under frame erasure conditions includes notifying an encoder in a receiving speech coder if a decoder in the receiving speech coder fails to receive a frame transmitted by an encoder in a transmitting speech coder. A modified packet is transmitted from the encoder in the receiving speech coder to a decoder in the transmitting speech coder in response to the notification. The decoder in the transmitting speech coder notifies the encoder in the transmitting speech coder when the modified packet is received. The encoder in the transmitting speech coder then encodes a packet with a modified encoding format. The modified encoding format may be either a low-memory encoding format or a memoryless encoding format. The modified packet may have an erasure indicator bit set to a digital value of one.

57. 发明专利

DE69621620D1 未知
公开(公告)号：DE69621620D1
公开(公告)日：2002-07-11
申请号：DE69621620
申请日：1996-08-01
申请人： QUALCOMM INC
发明人： GARDNER R , MANJUNATH SHARATH , MONTA PETER
IPC分类号： G10L19/02 , G10L19/00 , G10L19/04 , G10L19/06 , H03M7/30 , H03M7/36 , H04B14/04
摘要： A novel and improved method and apparatus for encoding line predictive coding (LPC) data in a speech compression system using line spectral square root values is disclosed. A novel and computationally efficient procedure for determining the set of quantization sensitivities for the line spectral square root values is disclosed, which results in a computationally efficient error measure for use in vector quantization of the line spectral square root values. A novel method of weighting the quantization error is disclosed, which accumulates the quantization error in each line spectral square root value and weights that error by the sensitivity of that line spectral square root value.\!

58. 发明专利

CA2380992A1 METHOD AND APPARATUS FOR IDENTIFYING FREQUENCY BANDS TO COMPUTE LINEAR PHASE SHIFTS BETWEEN FRAME PROTOTYPES IN A SPEECH CODER 未知
公开(公告)号：CA2380992A1
公开(公告)日：2001-01-25
申请号：CA2380992
申请日：2000-07-18
申请人： QUALCOMM INC
发明人： ANANTHAPADMANABHAN ARASANIPALA , DEJACO ANDREW P , MANJUNATH SHARATH , HUANG PENGJUN , CHOY EDDIE LUN TIK
IPC分类号： G10L19/02 , G10L19/00 , G10L19/04 , G10L19/12 , H03M7/36
摘要： A method and apparatus for identifying frequency bands to compute linear pha se shifts between frame prototypes in a speech coder includes partitioning the frequency spectrum of a prototype of a frame by dividing the frequency spectrum into segments, assigning one or more bands to each segment, and establishing, for each segment, a set of bandwidths for the bands. The bandwidths may be fixed and uniformly distributed in any given segment. The bandwidths may be fixed and non-uniformly distributed in any segment. The bandwidths may be variable and non-uniformly distributed in any given segmen t.

59. 发明专利

AU1524300A Closed-loop variable-rate multimode predictive speech coder 未知
公开(公告)号：AU1524300A
公开(公告)日：2000-06-05
申请号：AU1524300
申请日：1999-11-12
申请人： QUALCOMM INC
发明人： DAS AMITAVA , MANJUNATH SHARATH , DEJACO ANDREW P
IPC分类号： G10L19/18 , H03M7/36 , G10L19/14
摘要： A closed-loop, multimode, predictive speech coder includes a codec (100, 200) configured to operate in any of several coding modes, and a closed-loop mode decision module configured to apply a lowest-bit-rate coding mode to an input speech frame. A performance measure of the codec is obtained and compared with a threshold value. If the performance measure does not exceed the threshold value, the lowest-bit-rate coding mode is rejected in favor of a coding mode with a higher bit rate. The process can be continued until the coding performance is satisfactory. A higher-bit-rate, direct coding mode may be applied after a lower-bit-rate, prediction-based coding mode has failed to perform satisfactorily.

60. 发明专利

AU702506B2 Method and apparatus for generating and encoding line spectral square roots 未知
公开(公告)号：AU702506B2
公开(公告)日：1999-02-25
申请号：AU6688596
申请日：1996-08-01
申请人： QUALCOMM INC
发明人： GARDNER WILLIAM R , MANJUNATH SHARATH , MONTA PETER
IPC分类号： G10L19/02 , G10L19/00 , G10L19/04 , G10L19/06 , H03M7/30 , H03M7/36 , H04B14/04 , G10L9/14
摘要： A novel and improved method and apparatus for encoding line predictive coding (LPC) data in a speech compression system using line spectral square root values is disclosed. A novel and computationally efficient procedure for determining the set of quantization sensitivities for the line spectral square root values is disclosed, which results in a computationally efficient error measure for use in vector quantization of the line spectral square root values. A novel method of weighting the quantization error is disclosed, which accumulates the quantization error in each line spectral square root value and weights that error by the sensitivity of that line spectral square root value.\!

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