ENCODING DEVICE AND ENCODING METHOD

• US 20100049512A1
• Filed: 12/14/2007
• Published: 02/25/2010
• Est. Priority Date: 12/15/2006
• Status: Abandoned Application

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Oshikiri, Masahiro, Yamanashi, Tomofumi
• Application Number:
  US12/518,375
• Publication Number:
  US 20100049512A1
• Time in Patent Office: Days
• US Class Current: 704/230
• CPC Class Codes: G10L 19/038 Vector quantisation, e.g. TwinVQ audio
• CPC Class Codes: G10L 19/10 the excitation function being a multipulse excitation
• CPC Class Codes: H03M 7/3082 Vector coding for television signals, see H04N19/94

Abstract

Disclosed is an encoding device and others capable of suppressing quantization distortion while suppressing increase of a bit rate when encoding audio or the like. In the device, a dynamic range calculation unit (12) calculates a dynamic range of an input spectrum as an index indicating a peak of the input spectrum, a pulse quantity decision unit (13) decides the number of pulses of a vector candidate outputted from a shape codebook (14), and a shape codebook (14) outputs a vector candidate having the number of pulses decided by the pulse quantity decision unit (13) according to control from the search unit (17) by using a vector candidate element {−1, 0, +1}.

Claims

1. An encoding apparatus comprising:

a shape codebook that outputs a vector candidate in a frequency domain;

a control section that controls a distribution of pulses in the vector candidate according to sharpness of peaks in a spectrum of an input signal; and

an encoding section that encodes the spectrum using the vector candidate after distribution control.

2. The encoding apparatus according to claim 1, wherein the control section controls the distribution by changing a number of pulses in the vector candidate that is outputted from the shape codebook according to the sharpness of peaks.

3. The encoding apparatus according to claim 2, wherein the shape codebook outputs the vector candidate in which the pulses are allocated in the vicinity of frequencies of integral multiples of a pitch frequency of the input signal.

4. The encoding apparatus according to claim 1, further comprising a dispersing section that disperses the vector candidate using a dispersion vector,

wherein the control section control the distribution by changing a dispersion level in the dispersion vector according to the sharpness of peaks.

5. The encoding apparatus according to claim 1, further comprising a calculating section that calculates a dynamic range of the spectrum as an indicator to indicate the sharpness of peaks,

wherein the control section controls the distribution according to an amount of the dynamic range.

6. The encoding apparatus according to claim 5, further comprising another encoding section that performs encoding in a lower layer than the encoding section,

wherein the another encoding section comprises the calculating section.

7. The encoding apparatus according to claim 1, further comprising a decoding section that generates a decoded spectrum in a lower layer than the encoding section,

wherein the shape codebook outputs the vector candidate allocated the pulses only in a frequency band in which energy of the decoded spectrum is equal to or higher than a threshold.

8. A radio communication mobile station apparatus comprising the encoding apparatus according to claim 1.

9. A radio communication base station apparatus comprising the encoding apparatus according to claim 1.

10. A encoding method comprising:

controlling distribution of pulses in a vector candidate in a frequency domain according to sharpness of peaks in a spectrum of an input signal; and

encoding the spectrum using the vector candidate after distribution control.