Method and apparatus for coding or decoding wideband speech

• US 20060020450A1
• Filed: 10/03/2005
• Published: 01/26/2006
• Est. Priority Date: 04/04/2003
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Miseki, Kimio
• Granted Patent: US 7,788,105 B2
• Time in Patent Office: Days
• US Class Current: 704/219
• CPC Class Codes: G10L 19/18 Vocoders using multiple modes

Abstract

A wideband speech coding method comprising identifying whether an input speech signal is a narrowband signal or a wideband signal, and coding the input speech signal by controlling a predetermined parameter of a wideband speech coding process based on the identification result.

Claims

1. A wideband speech coding method comprising:

identifying whether an input speech signal is a narrowband signal or a wideband signal; and

coding the input speech signal by controlling a predetermined parameter of a wideband speech coding process based on the identification result.

2. A wideband speech coding method comprising:

identifying a sampling rate of an input speech signal; and

coding the input speech signal by controlling a predetermined parameter of a wideband speech coding process based on the identification result.

3. A wideband speech coding apparatus which represents a speech signal using spectrum parameter and excitation signal, comprising:

identification means for identifying whether an input speech signal is a wideband signal or a narrowband signal;

means for obtaining the spectrum parameter based on the input speech signal;

means for coding the excitation signal; and

control means for controlling the coding of the excitation signal using identification information from the identification means.

4. A wideband speech coding apparatus which represents a speech signal using spectrum parameter and excitation signal, comprising:

identification means for identifying whether an input speech signal is a wideband signal or a narrowband signal;

means for obtaining the spectrum parameter based on the input signal;

means for coding the excitation signal with a plurality of pulses; and

control means for controlling the coding of the pulses using identification information from the identification means.

5. A wideband speech coding apparatus which represents a speech signal using spectrum parameter and excitation signal, comprising:

identification means for identifying whether an input speech signal is a wideband signal or a narrowband signal;

means for obtaining the spectrum parameter based on the input speech signal;

means for coding the excitation signal with a plurality of pulses; and

control means for controlling position candidates of the pulses using identification information from the identification means.

6. A wideband speech coding apparatus sampling rate conversion means of input speech signal, comprising:

means for reducing the number of parameters or the number of coding candidates, regarding at least one means of;

(a) preprocessing means;

(b) spectrum parameter coding means;

(c) adaptive codebook searching means;

(d) excitation signal coding means; and

(e) gain coding means;

in correspondence with the sampling rate conversion of input speech signal.

7. A wideband speech coding apparatus comprising:

a plurality of wideband speech coding means having different bit rates;

identification means for identifying whether an input signal is a wideband signal or a narrowband signal; and

control means for controlling a bit rate of the wideband speech coding means using identification information from the identification means.

8. A wideband speech coding apparatus comprising:

means for identifying whether a speech signal is a wideband signal or a narrowband signal;

means for analyzing the spectrum of the speech signal to produce a target signal;

means for coding the target signal produced by the production means; and

bit rate control means for controlling the coding means in such a manner as to code the speech signal at a low bit rate in a case where the identification means identifies that the speech signal is the wideband signal and for controlling the coding means in such a manner as to code the speech signal at a high bit rate in a case where the identification means identifies that the speech signal is the narrowband signal.

9. A wideband speech coding apparatus having:

means for detecting that a sampling rate of a speech signal is lower than a predetermined value;

means for converting the speech signal into a speech signal whose sampling rate is the predetermined value; and

means for coding the converted speech signal, and

performing a process of reducing the number of parameters or the number of coding candidates in the coding means, as compared with the case where it is not detected when it is detected by the detection means that the sampling rate of the speech signal is lower than the predetermined value.

10. A wideband speech decoding apparatus having:

means for producing an excitation signal from coded data;

means for producing a synthesis filter; and

means for decoding a speech signal from the excitation signal and the synthesis filter, comprising;

acquisition means for acquiring identification information which identifies the speech signal to be decoded is narrowband; and

control means for controlling decoding means based on the identification information.

11. A wideband speech decoding apparatus having:

lower-band production means for producing a speech signal on a lower-band side; and

higher-band production means for producing a higher-band signal, comprising;

acquisition means for acquiring identification information which identifies that the speech signal to be decoded is narrowband; and

control means for controlling the lower-band production means based on the identification information.

12. A wideband speech decoding apparatus having:

means for producing an excitation signal from coded data;

means for producing a synthesis filter; and

means for decoding a speech signal from the excitation signal and the synthesis filter, comprising;

acquisition means for acquiring identification information which identifies that the speech signal to be decoded is narrowband; and

modification means for modifying the decoded speech signal or the excitation signal based on the acquired identification information.

13. A wideband speech decoding apparatus having:

lower-band production means for producing a speech signal on a lower-band side; and

higher-band production means for producing a higher-band signal, comprising;

acquisition means for acquiring identification information which identifies that a speech signal to be decoded is narrowband; and

modification means for modifying the speech signal or an excitation signal decoded in the lower-band production means based on the identification information.

14. A wideband speech decoding apparatus having:

means for producing an excitation signal from coded data;

means for producing a synthesis filter; and

means for decoding a speech signal from the excitation signal and the synthesis filter, comprising;

acquisition means for acquiring identification information which identifies that the speech signal to be decoded is narrowband; and

means for thinning out and accordingly sampling down the decoded speech signal or a signal resulting from the speech signal without using any band limiting filter in a case where narrowband is identified from the acquired identification information.

15. A wideband speech decoding apparatus having:

lower-band production means for producing a speech signal on a lower-band side; and

higher-band production means for producing a higher-band signal, comprising;

acquisition means for acquiring identification information which identifies that the speech signal to be decoded is narrowband; and

means for sampling down the decoded speech signal or a signal resulting from the speech signal by means of thinning-out without using any band limiting filter in a case where narrowband is identified from the acquired identification information.

16. A wideband speech decoding apparatus having:

lower-band production means for producing a speech signal on a lower-band side; and

higher-band production means for producing a higher-band signal, comprising;

means for acquiring identification information which identifies that the speech signal to be decoded is narrowband; and

means for controlling the higher-band production means based on the acquired identification information.

17. A wideband speech decoding apparatus having:

lower-band production means for producing a speech signal on a lower-band side; and

higher-band production means for producing a higher-band signal, comprising;

means for acquiring identification information which identifies that a speech signal to be decoded is narrowband; and

means for modifying the signal from the higher-band production means based on the acquired identification information.

18. A wideband speech coding apparatus having:

means for detecting that a speech signal is a narrowband signal;

means for reducing the number of parameters or the number of coding candidates in the coding means when a narrowband signal is detected by the detection means.