Apparatus and method for encoding and decoding of integrated speech and audio utilizing a band expander to output the audio or speech to a frequency domain encoder or an LPC encoder

• US 8,990,072 B2
• Filed: 07/14/2009
• Issued: 03/24/2015
• Est. Priority Date: 07/14/2008
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute, Kwangwoon University Industry
• Original Assignee: Electronics and Telecommunications Research Institute, Kwangwoon University Industry
• Inventors: Lee, Tae Jin, Baek, Seung-Kwon, Kim, Min Je, Jang, Dae Young, Seo, Jeongil, Kang, Kyeongok, Hong, Jin-Woo, Park, Hochong, Park, Young-cheol
• Primary Examiner(s): Kazeminezhad, Farzad
• Application Number:
  US13/054,376
• Publication Number:
  US 20110112829A1
• Time in Patent Office: 2,079 Days
• Field of Search: 704/500, 704/203
• US Class Current: 704/205
• CPC Class Codes: G10L 19/008 Multichannel audio signal coding or decoding using interchannel correlation to reduce redundancy, e.g. joint-stereo, intensity-coding or matrixing
• CPC Class Codes: G10L 19/02 using spectral analysis, e.g. transform vocoders or subband vocoders
• CPC Class Codes: G10L 19/12 the excitation function being a code excitation, e.g. in code excited linear prediction [CELP] vocoders
• CPC Class Codes: G10L 19/20 using sound class specific coding, hybrid encoders or object based coding
• CPC Class Codes: G10L 19/22 Mode decision, i.e. based on audio signal content versus external parameters
• CPC Class Codes: G11C 2207/16 Solid state audio deprecated, only for historical reasons, G06F3/16, G11B

Abstract

Provided are an apparatus and a method for integrally encoding and decoding a speech signal and a audio signal. The encoding apparatus may include: an input signal analyzer to analyze a characteristic of an input signal; a first conversion encoder to convert the input signal to a frequency domain signal, and to encode the input signal when the input signal is a audio characteristic signal; a Linear Predictive Coding (LPC) encoder to perform LPC encoding of the input signal when the input signal is a speech characteristic signal; a frequency band expander for expanding a frequency band of the input signal whose output is transmitted to either the first conversion encoder or the LPC encoder based on the input characteristic; and a bitstream generator to generate a bitstream using an output signal of the first conversion encoder and an output signal of the LPC encoder.

Claims

1. An encoding apparatus for integrally encoding a speech signal and an audio signal, the encoding apparatus comprising:

an input signal analyzer to analyze a characteristic of an input signal;

a frequency band expander to expand frequency band of the input signal;

a first conversion encoder to convert the input signal to a frequency domain, and to encode core band of the converted input signal if the analyzed input signal is an audio characteristic signal;

a Linear Predictive Coding (LPC) encoder to encode core band of the input signal based on LPC if the analyzed input signal is a speech characteristic signal; and

a bitstream generator to generate a bitstream using an output signal of the first conversion encoder and an output signal of the LPC encoder,

wherein the core band includes band which is not expanded in the frequency band of the input signal,

wherein an output of the frequency band expander is transmitted to either the first conversion encoder or the LPC encoder, according to the characteristic of the input signal.

2. The encoding apparatus of claim 1, further comprising:

a stereo encoder to down-mix the input signal to a mono signal, and to extract stereo sound information.

3. The encoding apparatus of claim 2, wherein the stereo encoder controls a parameter value for stereo encoding according to the characteristic of the input signal.

4. The encoding apparatus of claim 1, wherein the input signal analyzer classifies the input signal into any one of the audio characteristic signal, the speech characteristic signal, and a low energy signal.

5. The encoding apparatus of claim 4, wherein:

the speech characteristic signal is classified into any one of a low steady-harmonic state, and a steady-noise state, and

the audio characteristic signal is classified into any one of a complex-harmonic state and a complex-noisy state.

6. The encoding apparatus of claim 1, wherein the frequency band expander selectively applies at least one Spectral Band Replication (SBR) standard according to the characteristic of the input signal.

7. The encoding apparatus of claim 1, further comprising:

a psychological acoustic unit to control the first conversion encoder using an acoustic characteristic of a human being.

8. The encoding apparatus of claim 1, wherein the LPC encoder comprises:

a time domain encoder to perform time-domain encoding of the input signal performed LPC encoding if the input signal performed LPC encoding is the speech characteristic signal; and

a second conversion encoder to perform frequency-domain encoding of the input signal performed LPC encoding if the input signal performed LPC encoding is the audio characteristic signal.

9. An encoding apparatus for integrally encoding a speech signal and an audio signal, the encoding apparatus comprising:

an input signal analyzer to analyze a characteristic of an input signal;

a stereo encoder to down-mix the input signal to a mono signal, and to extract stereo sound information;

a frequency band expander to expand frequency band of the input signal;

a first conversion encoder to convert the input signal to a frequency domain, and to encode core band of the converted input signal if the analyzed input signal is an audio characteristic signal;

an LPC encoder to encode core band of the input signal based on LPC if the analyzed input signal is a speech characteristic signal;

and a bitstream generator to generate a bitstream using the stereo sound information for expanding the input signal to a high frequency band signal, an output signal of the first conversion encoder, and an output signal of the LPC encoder,

wherein the core band includes band which is not expanded in the frequency band of the input signal,

wherein an output of the frequency band expander is transmitted to either the first conversion encoder or the LPC encoder, according to the characteristic of the input signal.

10. The encoding apparatus of claim 9, further comprising:

a psychological acoustic unit to control the first conversion encoder using an acoustic characteristic of a human being.

11. The encoding apparatus of claim 9, wherein the stereo encoder controls a parameter value for stereo encoding according to the characteristic of the input signal.

12. The encoding apparatus of claim 9, wherein the frequency band expander selectively applies at least one SBR standard according to the characteristic of the input signal.

13. The encoding apparatus of claim 9, wherein the LPC encoder comprises:

a time domain encoder to perform time-domain encoding of the input signal performed LPC encoding if the input signal performed LPC encoding is the speech characteristic signal; and

a second conversion encoder to perform frequency-domain encoding of the input signal performed LPC encoding if when the input signal performed LPC encoding is the audio characteristic signal.

14. A decoding apparatus for integrally decoding a speech signal and an audio signal, the decoding apparatus comprising:

a bitstream analyzer to analyze an input signal included in the bitstream;

a conversion decoder to convert the input signal to a frequency domain, and to decode core band of the converted input signal if the analyzed input signal is an audio characteristic signal;

an LPC decoder to decode core band of the input signal based on LPC if the analyzed input signal is a speech characteristic signal;

a frequency band synthesizer to synthesize a frequency band of the input signal;

and a stereo decoder to decode the input signal to a stereo signal,

wherein the core band includes band which is not expanded in the frequency band of the input signal,

wherein an output of the bitstream analyzer is transmitted to either the conversion decoder or the LPC decoder, according to the characteristic of an input signal.

15. A method for integrally encoding a speech signal and an audio signal, the method comprising:

analyzing a characteristic of an input signal;

expanding frequency band of the input signal;

encoding the input signal having expanded frequency band;

generating, executed by a computer, a bitstream using an encoding result of the input signal,

wherein the encoding performs one of the below encoding methods according to characteristic of the input signal,

(i) converting the input signal to a frequency domain, and encoding core band of the converted input signal if the analyzed input signal is an audio characteristic signal;

or

(ii) encoding core band of the input signal based on LPC if the analyzed input signal is a speech characteristic signal,

wherein the core band includes band which is not expanded in the frequency band of the input signal.

16. The method of claim 15, further comprising:

down-mixing the input signal to a mono signal; and

extracting stereo sound information.

17. The method of claim 16, further comprising:

controlling a parameter value for stereo encoding according to the characteristic of the input signal.

18. The method of claim 15, wherein the expanding selectively applies at least one Spectral Band Replication (SBR) standard according to the characteristic of the input signal.