Hybrid speech coding and system

• US 20050065787A1
• Filed: 01/30/2004
• Published: 03/24/2005
• Est. Priority Date: 09/23/2003
• Status: Abandoned Application

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Stachurski, Jacek
• Application Number:
  US10/769,500
• Publication Number:
  US 20050065787A1
• Time in Patent Office: Days
• US Class Current: 704/229
• CPC Class Codes: B41F 27/1281 details of the printing plate ends
• CPC Class Codes: G01R 23/20 Measurement of non-linear distortion

Abstract

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.

Claims

1. A method of encoding speech filter coefficients, comprising:

(a) providing a first set of filter coefficients for a first location in a frame, a second set of filter coefficients for a second location in said frame, and a number of bits for encoding said second set;

(b) splitting said second set of filter coefficients into a plurality of subsets and allocating said number of bits to said subsets;

(c) for each of said subsets from step (b), determining interpolation coefficients according to said corresponding allocated bits;

(d) encoding said second set of filter coefficients with said interpolation coefficients from step (c).

2. The method of claim 1, wherein:

(a) said first location is the end of said frame;

(b) said second location is the middle of said frame.

3. The method of claim 1, wherein:

(a) said first set of filter coefficients are quantized.

4. The method of claim 1, wherein:

(a) said determining of step (c) of claim 1 is by minimizating an error from estimation of said second set of filter coefficients arising from interpolation of said first set of filter coefficients and a third set of filter coefficients of a preceding frame using said interpolation coefficients.

5. The method of claim 4, wherein:

(a) said third set of filter coefficients are for a location in said preceding frame corresponding to said first location of said frame.