Encoding Device, Decoding Device, and Method Thereof

• US 20080262835A1
• Filed: 05/17/2005
• Published: 10/23/2008
• Est. Priority Date: 05/19/2004
• Status: Active Grant

• Current Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Oshikiri, Masahiro
• Granted Patent: US 8,463,602 B2
• Time in Patent Office: Days
• US Class Current: 704/205
• CPC Class Codes: G10L 19/02 using spectral analysis, e.g. transform vocoders or subband vocoders
• CPC Class Codes: G10L 19/032 Quantisation or dequantisation of spectral components
• CPC Class Codes: G10L 21/038 using band spreading techniques
• CPC Class Codes: H04B 1/667 using a division in frequency subbands for TV signals H04N19/63

Abstract

There is disclosed an encoding device capable of improving similarity between the high frequency band spectrum of the original signal and a new spectrum to be generated while realizing a low bit rate when encoding a wide-band signal spectrum. The encoding device has sub-band amplitude calculation units (122, 128) for calculating the amplitude of the respective sub-bands for the high frequency band spectrum obtained from the wide-band signal. A search unit (124) and a gain codebook (125) select some sub-bands from a plurality of sub-bands and only the gain of the selected sub-bands is subjected to encoding. An interpolation unit (126) expresses the gain of the sub-band not selected, by mutually interpolating the selected gains.

Claims

1. A coding apparatus comprising:

an acquisition section that acquires a spectrum divided into at least a low frequency band and a high frequency band;

a first coding section that codes the low frequency band spectrum;

a second coding section that codes a shape of the high frequency band spectrum;

a third coding section that codes only gain of a specific location of the high frequency band spectrum; and

an output section that outputs coded information obtained by the first, second, and third coding sections.

2. The coding apparatus according to claim 1, wherein the third coding section:

comprises;

a determination section that determines gain of the specific location of the high frequency band spectrum;

an interpolation section that finds gain of a location other than the specific location in the high frequency band spectrum by interpolating gain of the specific location; and

a change section that compares a spectrum indicated by gain found by both the determination section and the interpolation section with the high frequency band spectrum, and changes gain determined by the determination section according to similarity of these spectrum, and

codes gain after being changed by the change section.

3. The coding apparatus according to claim 1, wherein the third coding section codes gain in a vicinity of a lowest frequency of the high frequency band spectrum.

4. The coding apparatus according to claim 1, wherein the third coding section codes gain in a vicinity of a highest frequency of the high frequency band spectrum.

5. The coding apparatus according to claim 1, wherein the third coding section codes gain of a minimum point or maximum point of the high frequency band spectrum.

6. The coding apparatus according to claim 1, further comprising a fourth coding section that codes information relating to at least one location among the specific locations used by the third coding section;

wherein the output section also outputs coded information obtained by the fourth coding section.

7. A layered coding apparatus that generates coded information having scalability in a frequency axis direction, and uses the coding apparatus according to claim 1 for extension layer coding.

9. A communication terminal apparatus comprising the coding apparatus according to claim 1.

11. A base station apparatus comprising the coding apparatus according to claim 1.

8. A decoding apparatus that decodes coded information relating to a spectrum divided into at least a low-frequency band and a high frequency band, comprising:

a first decoding section that decodes coded information relating to the low frequency band spectrum;

a second decoding section that decodes coded information relating to gain of a specific location of the high frequency band spectrum; and

a third decoding section that decodes the high frequency band spectrum using gain obtained by the second decoding section.

10. A communication terminal apparatus comprising the decoding apparatus according to claim 8.

12. A base station apparatus comprising the decoding apparatus according to claim 8.

13. A coding method comprising:

an acquisition step of acquiring a spectrum divided into at least a low frequency band and a high frequency band;

a first coding step of coding the low frequency band spectrum;

a second coding step of coding a shape of the high frequency band spectrum;

a third coding step of coding only gain of a specific location of the high frequency band spectrum; and

an output step of outputting coded information obtained in the first, second, and third coding steps.

14. A decoding method of decoding coded information relating to a spectrum divided into at least a low frequency band and a high frequency band, comprising:

a first decoding step of decoding coded information relating to the low frequency band spectrum;

a second decoding step of decoding coded information relating to gain of a specific location of the high frequency band spectrum; and

a third decoding step of decoding the high frequency band spectrum using gain obtained in the second decoding step.