公开(公告)号：AT456846T

公开(公告)日：2010-02-15

申请号：AT06785795

申请日：2006-06-29

Applicant: MOTOROLA INC

Inventor： ASHLEY JAMES ,  MITTAL UDAR

IPC: G10L19/08 ,  G10L25/90

Abstract: In a speech encoder/decoder a pitch delay contour endpoint modifier is employed to shift the endpoints of a pitch delay interpolation curve up or down. Particularly, the endpoints of the pitch delay interpolation curve are shifted based on a variation and/or a standard deviation in pitch delay.

公开(公告)号：BRPI0407593A

公开(公告)日：2006-02-21

申请号：BRPI0407593

申请日：2004-12-17

Applicant: MOTOROLA INC

Inventor： JASIUK MARK A ,  RAMABADRAN TENKASI V ,  MITTAL UDAR ,  ASHLEY JAMES P ,  MCLAUGHLIN MICHAEL J

IPC: G10L19/08 ,  G10L25/90 ,  G10L11/04 ,  G10L19/00 ,  G10L19/12 ,  G10L19/10 ,  G10L19/04

Abstract: A method and apparatus for prediction in a speech-coding system extends a 1st order long-term predictor (LTP) filter, using a sub-sample resolution delay, to a multi-tap LTP filter. From another perspective, a conventional integer-sample resolution multi-tap LTP filter is extended to use sub-sample resolution delay. Such a multi-tap LTP filter offers a number of advantages over the prior-art. Particularly, defining the lag with sub-sample resolution makes it possible to explicitly model the delay values that have a fractional component, within the limits of resolution of the over-sampling factor used by the interpolation filter. The coefficients (betai's) of the multi-tap LTP filter are thus largely freed from modeling the effect of delays that have a fractional component. Consequently their main function is to maximize the prediction gain of the LTP filter via modeling the degree of periodicity that is present and by imposing spectral shaping.

公开(公告)号：AU2003287595A1

公开(公告)日：2004-06-03

申请号：AU2003287595

申请日：2003-11-06

Applicant: MOTOROLA INC

Inventor： MITTAL UDAR ,  ASHLEY JAMES P ,  CRUZ EDGARDO M

IPC: G10L19/00 ,  G10L19/12 ,  G10L25/90 ,  G10L25/93 ,  G10L19/08 ,  G10L19/10 ,  G10L19/14 ,  G10L19/06 ,  G10L11/04 ,  G10L11/06

Abstract: A CELP encoder is provided that optimizes excitation vector-related parameters in a more efficient manner than the encoders of the prior art. In one embodiment, a CELP encoder optimizes excitation vector-related parameters based on a computed correlation matrix, which matrix is in turn based on a filtered first excitation vector. The encoder then evaluates error minimization criteria based on at least in part on a target signal, which target signal is based on an input signal, and the correlation matrix and generates a excitation vector-related index in response to the error minimization criteria. In another embodiment, a CELP encoder is provided that is capable of jointly optimizing and/or sequentially optimizing multiple excitation vector-related parameters by reference to a joint search weighting factor, thereby invoking an optimal error minimization process.