Voice encoding device, voice decoding device, and methods therefor

• US 8,364,495 B2
• Filed: 09/01/2005
• Issued: 01/29/2013
• Est. Priority Date: 09/02/2004
• Status: Active Grant

• Current Assignee: III Holdings 12, LLC (Intellectual Ventures LLC)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Morii, Toshiyuki
• Primary Examiner(s): Shah, Paras D
• Assistant Examiner(s): Baker, Matthew
• Application Number:
  US11/574,543
• Publication Number:
  US 20070271102A1
• Time in Patent Office: 2,707 Days
• Field of Search: 704/E19.044, 704/500, 704/222, 704/223, 704/219, 704/220
• US Class Current: 704/500
• CPC Class Codes: G10L 19/24 Variable rate codecs, e.g. for generating different qualities using a scalable representation such as hierarchical encoding or layered encoding

Abstract

An encoding device capable of realizing a scalable CODEC of a high performance. In this encoding device, an LPC analyzing unit (551) analyzes an input voice (301) efficiently with a synthesized LPC parameter obtained from a core decoder (305), to acquire an encoded LPC coefficient. An adaptive code note (552) is stored with its sound source codes, as acquired from the core decoder (305). The adaptive code note (552) and a stochastic code note (553) send sound source samples to a gain adjusting unit (554). This gain adjusting unit (554) multiplies the individual sound source samples by an amplification based on the gain parameters acquired from the core decoder (305), and then adds the products to acquire sound source vectors. These vectors are sent to an LPC synthesizing unit (555). This LPC synthesizing unit (555) filters the sound source vectors acquired at the gain adjusting unit (554), with the LPC parameter, to acquire a synthetic signal.

Claims

1. A speech encoding apparatus that encodes an input signal using encoded information of n layers, n being an integer greater than or equal to 2, the speech encoding apparatus comprising:

a base layer encoder that encodes the input signal to generate the encoded information of layer 1;

a decoder of layer i that decodes the encoded information of layer i , i being an integer greater than 1 and less than or equal to n−

1, to generate a decoded signal of layer i;

an adder, comprising a processor, that adds either a difference signal of layer 1 which is a difference between the input signal and the decoded signal of layer 1 or a difference signal of layer i which is a difference between the decoded signal of layer i−

1 and the decoded signal of layer i; and

an enhancement layer encoder of layer i+1 that encodes the difference signal of layer i to generate encoded information of layer i+1;

wherein the enhancement layer encoder of layer i+1 performs an encoding process utilizing decoding parameters received separately from the difference signal and from a decoding section of layer j, j being an integer less than or equal to i and obtained in the decoding process of the decoding section of layer j.

2. A speech encoding apparatus according to claim 1 wherein the enhancement layer encoder of layer i+1 is a CELP type encoder that utilizes LPC parameter information obtained through decoding in the decoding section of layer j.

3. A speech encoding apparatus according to claim 1 wherein the enhancement layer encoder of layer i+1 is a CELP type encoder that utilizes information of an adaptive codebook obtained through decoding in the decoder of layer j.

4. A speech encoding apparatus according to claim 1 wherein the enhancement layer encoder of layer i+1 is a CELP type encoder that utilizes gain information obtained through decoding in the decoder of layer j.

5. A speech decoding apparatus that decodes encoded information of n layers, n being an integer greater than or equal to 2, the speech decoding apparatus comprising:

a base layer decoder that decodes the inputted encoded information of layer 1;

a decoder of layer i that decodes the encoded information of layer i+1, i being an integer greater than 1 and less than or equal to n+1, to generate a decoded signal of layer i+1; and

an adder, comprising a processor, that adds the decoded signal of each layer,

wherein the decoder of layer i+1 performs a decoding process utilizing decoding parameters received separately from the encoded information of layer i+1 and from a decoder of layer j, j being an integer less than or equal to i and obtained in a decoding process of the decoder of layer j.

6. A speech decoding apparatus according to claim 5 wherein the decoder of layer i+1 is a CELP type decoder that utilizes LPC parameter information obtained through decoding in the decoder of layer j.

7. A speech decoding apparatus according to claim 5 wherein the decoder of layer i+1 is a CELP type decoder that utilizes information of an adaptive codebook obtained through decoding in the decoder of layer j.

8. A speech decoding apparatus according to claim 5 wherein the decoder of layer i+1 is a CELP type decoder that utilizes gain information obtained through decoding in the decoder of layer j.

9. A speech encoding method that encodes input signals using the encoded information of n layers, n being an integer greater than or equal to 2, the speech encoding method comprising:

a base layer encoding process that encodes the input signal to generate the encoded information of layer 1,

a decoding process of layer i that decodes the encoded information of layer i, i being an integer greater than 1 and less than or equal to n−

1 to generate the decoded signal of layer i;

an addition process that either determines a difference signal of layer 1 which is a difference between the input signal and the decoded signal of layer 1 or a difference signal of layer i which is a difference between the decoded signal of layer i−

1 and the decoded signal of layer i; and

an enhancement layer encoding process of layer i+1 that encodes the difference signal of layer i to generate encoded information of layer i+1;

wherein the enhancement layer encoding process of layer i+1 an encoding process utilizing decoding parameters received separately from the difference signal and from a decoding process of layer j, j being an integer less than or equal to i and obtained in the decoding process of layer j.

10. A speech decoding method that decodes encoded information of n layers, n being an integer greater than or equal to 2, the speech decoding method comprising:

a base layer decoding process that decodes the inputted encoded information of layer 1;

a decoding process of decoding encoded information of layer i+1, i being an integer greater than 1 and less than or equal to n−

1 to generate a decoded signal of layer i+1; and

an addition process that adds the decoded signal of each layer;

wherein the decoding process of layer i+1 performs a decoding process utilizing decoding parameters received separately from the encoded information of layer i+1 and from a decoding process of layer j, j being an integer less than or equal to i and obtained in the decoding process of layer j.